Midwest State's Regional Pooled Fund Research Program Fiscal Year 1996-1997 (Year 7)

NDOR Research Project Number SPR-3(01 7)

CONCEPT DEVELOPMENT OF A BULLNOSE

GUARDRAIL SYSTEM FOR MEDIAN

APPLICATIONS

Bob W. Bielenberg Graduate Research Assistant

Jolm D. Reid, Ph.D. Associate Professor

Dean L. Sicking, Ph.D., P.E.

Submitted by

Associate Professor and MwRSF Director

Ronald K. Faller, Ph.D., P.E. Research Associate Engineer

John R. Rohde, Ph.D., P.E. Associate Professor

Eric A. Keller, E.I.T. Computer Design Technician II

MIDWEST ROADSIDE SAFETY FACILITY Civil Engineering Department

University of Nebraska-Lincoln 1901 "Y" Street, Building "C"

Lincoln, Nebraska 68588-060 I (402) 472-6864

Submitted to

MIDWEST STATE'S REGIONAL POOLED FUND PROGRAM Nebraska Department of Roads

I 500 Nebraska Highway 2 Lincoln, Nebraska 68502

MwRSF Research Report No. TRP-03-73-98

May 22, 1998

Technical Report Documentation Page 1. l~eport No. 2. 3. Recipient's Accession No.

SPR-3(017) 4. 'l'itle and Subtitle 5. Report Date

Concept Development of a Bullnose Guardrai l System for May 22, 1998 Median Applications

6.

7. Author(s) 8. l)crforming OrgMiZ.1tion Report No.

Bielenberg, B.W., Faller, R.K., Reid, J.D. , Rohde, J.R., TRP-03-73-98 Sicking, D.L. , and Keller, E.A.

9. Perfonning Org<mization Name and Ad~ress 10. l•rojcctffask/Work Unit No.

Midwest Roadside Safety Facility (MwRSF) University of Nebraska-Lincoln 1901 Y St., Bldg. C II. Contmct 0 or Grant (G) No.

Lincoln, NE 68588-060 I SPR-3(0 17)

12. Sponsoring Organization Name and A:!drcss 13. TypeofRep011 and Period Covered

Midwest States Regional Pooled Fund Program Final Report 1997- 1998 Nebraska Department of Roads

14. Sponsoring Agency Code 1500 Nebraska Highway 2 Lincoln, Nebraska 68502

IS. Suppleme-ntnry Notes

Prepared in cooperation with U.S. Department of Transportation, Federal Highway Administration

16. Abstract (Limit: 200 words)

The research study consisted of the design, fabrication, and full-scale vehicle crash testing of a bullnose barrier concept for the end treatment of median hazard;. The bullnose concept consisted of a 12-gauge thrie beam rail supported by twenty-two wood posts, eleven posts on each side of!he system. Horizontal slots were cut in the valleys of selected thrie beam sections to aid in vehicle capture as well as to reduce the buckling and bending capacities of the rail.

Two full-scale crash tests were performed, the first using a 2000-kg pickup truck and the second using an 820-kg small car. The first test, impacting at a speed of 101.4 kmlh and an angle ofO. I degrees at a !!.-point offset, was unsuccessful. Although the vehicle showed no potential for vehicle override, the thrie beam ruptured causing uncontrolled penetration of the vehicle behind the barrier. Consequently, the bullnose system was modified to include additional breakaway posts and horizontal s lots in other thrie beam sections. The second test, impacting at a speed of 103.3 km/h and an angle of3.4 degrees was detenuined to be successful according to the safety standards set f01th by the Test Level 3 evaluation criteria described in the National Cooperative Highway Research Report No. 350, Recommended Procedures for the Safety Petformance Evaluation of Nighway Features. The data and information gathered from the development phase of this project will be used in the development of a computer simulation LS-DYNA model of the bullnose system as well as an improved bullnose guardrail design.

17. Document Analysis/Descriptors 18. Availabi lity Statement

Highway Safety, Guardrail . Roadside Appm1enances, Crash No restrictions. Document available from: Longitudinal Barrier, Bullnose Barrier, Test, Compliance Test National Technical Information Services, Median Barrier, End Tenninal, Springfield, Virginia 22161

19. Security Class (this report) 20. Security Class (this page) 2 1. No. of Pages 22. Price

Unclassified Unclassified 93

DISCLAIMER STATEMENT

The contents of tlus report reflect the views of the authors who are responsible for the facts

and the accuracy of the data presented herein. The contents do not necessarily reflect the official

views or policies of the state highway departments participating in the Midwest State's Regional

Pooled Fund Program or the Federal Highway Administration. This report does not constitute a

standard, specification, or regulation.

II

ACKNOWLEDGMENTS

The authors wish to acknowledge the following organizations that made this project possible:

(I) the Midwest States Regional Pooled Fund Program funded by the Iowa Department of

Transportation, Kansas Department of Transportation, Minnesota Department of Transportation,

Missouri Department of Transportation, Nebraska Department of Roads, Ohio Department of

Transportation, South Dakota Department of Transportation, and Wisconsin Department of

TranspOrtation tor sponsoring this project; (2) MwRSF personnel for constructing the barriers and

conducting the crash tests; ( 4) Center for Infrastructure Research, Engineering Research Center, for

matching support; (5) the Federal Highway Administration for matching support; and (6) Daniel

Mushett of Buffalo Specialty Products- Timber Division for donating timber posts and blockouts.

A special thanks is also given to the following individuals who made a contribution to the

completion of this research project.

Midwest Roads ide Safety Facility

Brian G. Pfe ifer, Ph.D., P.E., Research Associate Engineer James C. Holloway, MSCE, E.I.T., Research Associate Engineer Kenneth L. Krenk, BSMA, Field Operations Manager Michael L. Hanau, Laboratory Mechanic I Undergraduate and Graduate Assistants

Missouri Department of Transportation

Vince Imhoff, P.E., Senior Research and Development Engineer

Nebraska Department of Roads

Leona Kolbet, Research Coordinator Ken Sieckmeyer, Transportation Planning Manager

Ill

Kansas Department of Transportation

Ron Seitz, P .E., Road Design Squad Leader

Iowa Department of Transpor tation

David Little, P.E., Design Methods Engineer

Minnesota Department of Transportation

Ron Cassell ius, Research Program Coordinator Glenn Korfhage, P.E., Design Standards Engineer

Ohio Department of Transportation

Larry Sha1mon, P.E., Standards and Geometries Engineer Monique Evans, P.E. Standards Engineer

South Dakota Department of Transportaion

David Huff, P.E. , Research Engineer

Wisconsin Department of Transpor tation

Rory Rhinesmith , P.E., Chief Roadway Development Engineer Fred Wisner, Standards Development Engineer

Federal Highway Administration

Mi lo Cress, P.E., Nebraska Division Office

Dunlap P hotography

James Dunlap, President and Owner

IV

TABLE OF CONTENTS Page

TECHNICAL DOCU.\t!ENTATION PAGE . . . . .. .. .. . .. . .. . .. . .. . . . .. . . . .... . . . . . . . i

DISCLAIMER STATEMENT . .. .. . ... . ... . ...... . .. . .. . .. . .. . . . .. . . . . . .... . . . . u

ACKNOWLEDGMENTS . .. .. .. .. . ... . .. . ... . ... . .. . .. • .. .. . . ... . .. .. . . .... ... iii

TABLE OF CONTENTS .. . . .. . ... . .......... ... . . .. . . .• .. . . . . . . . . .. . . . ... . . ... . v List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii List of Tables .. . ... . .. . ... . ...... . . . . . .. . . .. . . . . .. . . . .. . . . .. . . . . . . . .... ix

I INTRODUCTION .. . .. .. .. .. . .. .. .. .. . ... . .. . ....... . .. . . .. . . . .. .. • ... . . .... I 1.1 Background and Problem Statement ... . .. . .... . . ... . . . .. . . . . . . . • ... . ..... I 1.2 Obj ective and Scope of Design . ...... . .. . . . . .. . . .... . .. . . . .. . . • . . . . ..... 2 1.3 Previous Designs . .. . ... . ...... . ... ... . ... . . . . . .. . . .. . . . .... • . . . . . . ... 3

2 BARRIER DES!Gl\ . . .. . .. . . .. . . .. .. . .• ... . . .• .. . .. . . . . .. • .... • .... . . . . . ..... 8 2. 1 Rai l Concepts .. . .. .. .. . . .. . .. .. .. . .. . . .. . .. . .. . .. . . . .. . .... . . . . . . . . .. 8 2.2 Nose Section Design . . . . . .. . . .. . .. . . .. . . . . .. . . . ..... . . . ...... . ... . I I 2.3 Barrier Design Detai ls .. . .. .. .. .. .. . .. . .. . . .. . .. . ......... . ...... . . . . . I I

3 PERFORMANCE EVALUATION CRITERIA . . .. . . . ... . . . ... . .. . . . .. . . . ...... . . . 2 1 3. 1 Test Requirements .. . .. . .. .. .. . . . . . .. . . . . . . . . . ... . .. . . . . . . . . . . .... . . . 21 3.2 Evaluation Criteria . . .. . ... . .. .• ... . . . . ..... . ..... . .. . . . .. . . . . . .. . . . . . 23

4 TEST CONDITIONS .. . .. .. . . . ... . ... . .. .. .. . .. . .. . .. . .. . .. . . . .... . . . . . .. ... 25 4.1 Test Facility .. . .. .. . . . ... . ... . .. .. .. . .. .. . . .. . .. . .. . . . .... • . . . . .... . 25 4.2 Vehic le Tow and Guidance System .. . ... . .. . .. . .. . .. . .... . .... . . . . . .... . 25 4.3 Test Vehicles . . .. . .. . . ... . ... . .. . ... . .. . .. . .. . .. . .... . .... . . . . . ... .. 25 4.4 Data Acquisition Systems .. . .. . . .. . ... . .. . .. . .. . .. . .... • ..... . . . . .. ... 31

4.4 .1 Accelerometers .. .. . .. ... . .. . . .. . .. . .. . .. . . .. . . . . .. . . . . . . . ... 31 4.4.2 Rate Transducers . . ... . . . . . . . . ... . .. . .. . .. . . . .. . . . .. . . . . . . . . . . 31 4.4.3 High Speed Photography .. . .. . .. .. .. . . .. .... . .... . ...... • .. . . . 32 4.4.4 Pressure Tape Switches . .. .. .. . .. . .. . .... . . .. .. .. ... .. ... . .. . . . 32 4 .4.5 Strain Gauges .. .. .. .. .. . .. . . .. . .. . .. . . . • ... . .. ... . . .. .. ... . . 35

5 CRASH TEST MBN- 1 .. .. .. . ... . ... . .. . . . .•. .... . . .... .. . .. .. .... . . . . . ...... 37 5.1 Test MBN-1 . .. . . . . . .... . . . . . . . .. . . . . . .. .. .... . .. . .. . . . .... . . . . . . . . . 37 5.2 Test Description ... . . .. .. . .. . . .. .. . ... . . . .. .... • .. . . . .. . . . .. . . . . . . . . . 37 5.3 Vehicle Damage . .. . ... . .. .. . . . .. .• ...... . .. . .. . . .. . . .. . . . . . .. . . . ... . 37 5.4 Barrier Damage ... . ... . .. . . .. . .. . . .. . .. . . . .. .. . . .. . . . . .. . . . ...... . . . 38

v

5.5 Occupant Risk Values ....... . .. . . ..•. .......... .•. ... •. .............. 38 5.6 Discussion ............... . ..... ..•. ........... • .... •. . . ............ 39 5. 7 Barrier lnsliUIIlentation Results ........... .... .... . .... .• ........ . ...... 40

6 BARRIER MODIFICATIONS (DESIGN FOR MBN-2) ... ... . .... . .. . . . .... . . . . ... 49

7 CRASH TEST MBN-2 . . .. • . .... .. • ...... .• .. ...... . . .. . .... . .. .. • ........... 58 7.1 Test MBN-2 .... . .. ...... • . .. ... . . ... . .. . .. . .. • .... . .... • .... ... . ... 58 7.2 Test Description ... •...... • . .. ... . • ...... . .. . .. . .... . .. . . . ........... 58 7.3 Vehicle Damage .... ...... • ... . .. .• .. ... . ..... . ... .. . .... . ........ ... 58 7.4 Barrier Damage .. . ....... • ... . .. . . .. ... . ..... . .... . • .... • ... . .... ... 59 7.5 Occupant Risk Values .... . ....... • ... ... ......... . ........... . ..... .. 59 7.6 Discussion ....... ......... . .... . ............................... . ... 60

8 SUMMARY AND CONCLUSIONS . .. . ..................................... ... 71

9 RECOMMENDATIONS ...... .. . ....... . ... . .. ...... ... . .. . ............... .. 73

I 0 REFERENCES . ... . . . . . ...... • . ..... . ............. ... . ........... . ... .. . . . 74

11 APPENDICES . . .. . ... . ........................ . ....... . .... ... .. • . .. ... .. 76 APPENDIX A- ACCELEROMETER DATA ANALYSIS ... . .... ... .. • . .. .. ... 77 APPENDIX B- STRAIN GAUGE DATA ........ . ....... . .... • .. .. . .. . ... .. 91

VI

LIST OF FIGURES Page

I. Minnesota Bullnose Barrier Design ... . . .. . .. . ... . . . . .. . .. . .. . .... . .. . . . . . . . ..... 5 2. Colorado Bullnose Barrier Design . ... . ... . .. . ... . .. . .. . . . . .. . .... . .. . . . . . . . ..... 6 3. Southwest Rt>.se~~rch Institute Bullnose B~rrier Design .. . ..... . .. ..... .. .... . __ . _ . . . . 7 4. Preliminary W-Beam Bullnose Barrier Design Concepts . .. . .. . .. . . . .. . . . .... . . . . . . . . 9 5. Preliminary W-Beam Bullnose Barrier Design Concepts . .. . .. . .. . . . ... .... . . . . . . . .. 10 6. Bullnose Barrier Design Layout . .. .. . .. . . ... . .. . .. . .. . .. . .. . . . .. . . . .. . . • ... . .. 12 7. Modified Groundline Strut ... . ... . .. .. . . . .. . . .. . .. . .. . .. . .. . . . .. . . . .. . . • . . . . .. 14 8. Layout of Bullnose Rai ls No. I and 2 ..... . .. .. .... .. .. .. . . .. . . . . . . .. .. . . . . . . . .. 16 9. Rail Section No. I Detail .. .. . .. .. .. . ... .. .. . .. . .. . ..... . ...... . . . . . . . . • . . . . .. 17 I 0. Rail Section No. 2 Detail .. . ... . ... .. . . ... . ...... . .. . ............ . . . . . . . . . .. 18 I I. Bullnose Barrier Design .... . ... . ....... . .. . ...... . .. . ... .. .. . .... . . . . . ...... 19 12. Bullnose Barrier Design .. .. .. .. .. . . ... .. .. . ... . .. . .. . .. . ......... . . . . . ...... 20 13. Proposed Full Scale Crash Tests for Bullnose Barrier Evaluation .... . .. .. . . . . . ...... 22 14. Vehicle Dimensions, Test MBN-1 ........ . .. . . . ..... . . . .... .. . • .... • . . . . ...... 26 15. Vehicle Dimensions, Test MBN-2 . . .. . . . . . .. . . . . . .. • .. . . . . .. . . • .... • . . . . .. . ... 28 16. Vehicle Target Locations, Test MBN- 1 .... . .. . ... . .. • .. . .. • .... . ... . • ... . ...... 29 17. Vehicle Target Locations, Test MBN-2 .... . ... . .. . .. . .. . .. • .... . .. .. . ... . .. . ... 30 18. Location of High-Speed Cameras, Test MBN-1 . . .. . .. . .. . .. . .... . .... • ... . .. . . . . 33 19. Location of High-Speed Cameras, Test MBN-2 .. . .. .. . .. . .. . . .. . . .... • . . . . ...... 34 20. Strain Gauge Locations, Test MBN-1 . . ... .. . .. .. . .. . . . . .. . .. . . . .. . . . ... . .... . . 36 21. lmpact Location, Test MBN-1 . ... . .. . ... . ... . .. . . .. .. . ..... . .. .. . .. . . ...... . . 41 22. Summary and Sequential Photos, Test MBN-1 . .. .. . .. . .. . .. . . .. . . .. . . . ........ . . 42 23. Additional Sequential Photos, Test MBN-1 . .. .. .. . .. . .. . .. . .. . . . .. . . • ... . ...... 43 24. Vehicle Tr~jectory, Test MBN-1 . .. .. .. .. .. .. . .. . .. . . . . .. . .. . . . .. . . . .......... 44 25. Vehicle Damage, Test MBN-1 .. .. . ... . .. .. .. . .. . .. . . . . .. . .. . . . . . . . . . . ...... . . 45 26. Barrier Damage, Test MBN-1 .. .. . .. .. .. .. .. . .. .. . . . . .. . . .. . . . .. . . . ........ . . 46 27. Barrier Damage, Test MBN-1 . ... . ...... . ... . .. . .. . . . . .. . .. . . . . . . . . .. . . . ... . . 47 28. Bullnose Barrier Design, Test MBN-2 .... . ... . .. . .. . ..... . ....... . . . .. . . . . . . . . 51 29. Bullnose Design for Test MBN-2 . . .. .. ... . . . • .. . . . . . .... . . . . .... . . . ........ . . 52 30. Bullnose Design for Test MBN-2 . . . .. . ... . . .• .. . . . . . . .. . . .. ..... . . . .... . ... . . 53 31. Rail No. I Detail, Test MBN-2 ... . . . .. .. . . . . • .. . .. .. . . .. . . . . . . .. . . . .... . ... . . 54 32. Rail No.2 Detail, Test MBN-2 ... . . . .. .... . . . . . ... . . . ... .. . .. .. . . . . . ....... . . 55 33. Rail No.3 Detail, Test MBN-2 ... . .. .. .. . ... . .. . . . .. .... . . . .. .. . . . . ........ .. 56 34. Impact Location, Test MBN-2 . ... . .. .. .. . ... . .. . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 61 35.Summary and Sequential Photographs, Test MBN-2 . . . . .. .... • .... . . ... . . .. . . . . . . . 62 36. Additional Sequential Photographs, Test MBN-2 . .. . . . . ..... • .... . .... . . .. .. . . . . . 63 37. Full Scale Test, Test MBN-2 ............ . .. . ...... . ..... . .... . .... • ... . ... ... 64 3l!. Full ::>cale Test, Test MBN-2 . .. ..... . ... . .. • ... . . . . .... . .. ... . .... • . . . . .. . ... 65 39. Vehicle Trajectory, Test MBN-2 . . ... . .. . ... . .. .. .. . .. . .... . .. . .... . ... . . ... .. 66 40. Vehicle Damage, Test MBN-2 .. .. ...... .. .. . .. .. . . . . .. . . . . . .. . . . .. . . . . . ...... 67

VII

41. Barrier Damage, Test MBN-2 ... . .... . . .. .. . . . .. .. . .. . .. . ... . . .... . .. . . . . . . . . 68 42. Barrier Damage, Test MBN-2 ... . .... . . .. .. .. .. . .. . .. . .. . ... . . . .. . . .. . . . . . . . . 69 43. Permanent Rail Deflection, Test MBN-2 .. .. .. .. .. . .. . .. . .. . ... . . . .. . . . .. . . . . . . . 70 A-1. Graph of Angular Displacements, Test MBN- 1 . . . . ......... . ... .. . . . .. .. . • ... . . 78 A-2. Graph of Longitudinal Deceleration, Test MBN-1 . . ....... . . .... .. . . . .. .. . . . . . . . 79 A-3 Graph of Longitudinal Occupant Impact Velocity, Test MBN-1 . ... .. .... . .. . . • . . . . . 80 A-4. Graph of Longit~dinal Occupant Displacement, Test MBN-1 . .. . . .. .... . .... . . . . . . 8 1 A-5. Graph of Lateral Deceleration, Test MBN-1 ...... .. . .. . .. . .. . . .. . . . . . .... . ... . . 82 A-6. Graph of Lateral Occupant Impact Velocity, Test MBN-1 .... . .. . .. . . . .... . . • .. . . . 83 A-7. Graph of Lateral Occupant Displacement, Test MBN- 1 .. . .. . ..... . .. . .. . . . . . ... . . 84 A-8. Graph of Longitudinal Deceleration, Test MBN-2 ....... .. . ..... . .. . .... . . . . . . . . 85 A-9. Graph of Longitudinal Occupant Impact Velocity, Test MBN-2 .. . . . .... . .... . . . . . . 86 A-1 0. Graph of Longi tudinal Occupant Displacement, Test MBN-2 . .. . . .. . . . . . .. . • ..... 87 A-ll. Graph of Lateral Deceleration, Test MBN-2 . . . .. . .. .. . . . . . .. . . . . .. . . .... . . . . . . 88 A-1 2. Graph of Lateral Occupant Impact Velocity, Test MBN-2 . .. . . . . . .. . . . . . .. . ...... 89 A-1 3. Graph of Lateral Occupant Displacement, Test MBN-2 .. . .. . . . . . .. . .. . . .. . . . . . .. 90 B-1. Strain Gauge No. 3 Data, Test MBN- 1 . .. . ... . .. . .. . .. . .. . . . .. . . ... . . .. . . . . . . . 92 B-2. Strain Gauge No. 4 Data, Test MBN- 1 . . .... . . . ... . . . . ... . . . . . .. . . . .. .. ... . .. . 93

VII I

LIST OF TABLES Page

I. NCHRP Rcpon 350 Evaluation Criteria for 2000P Pickup Truck Crash Test 3-31 and 820C Small Car Crash Test 3-30 .............................................. ...... ....... 24 2. Strain Gauge Locations ........... .. ......... . .. .... .. • .............. • . ...... 36 3. Strain Gauge Data, Test MBN-1 ...... . ... . .. .... . . ..... . ....... .... ... . ... . .. . 48 4. Summary of Safety Performance Evaluation ......... . ..... . .... . ..... . ....... . ... 72

IX

1 INTRODUCTION

1.1 Background and Problem Statement

The use of the divided highway separated by a median area has been a valuable safety feature

in modern roadway design. The median allows a safe recovery area for errant vehicles to come to

rest without impeding upon oncoming traffic. It is possible, however, that the median is not always

a safe zone for vehicle recovery. Many roadway structures are built in the median such as bridge

supports, drainage structures, and large sign supports. These structures present hazards to vehicles

in the median.

There arc three main treatments that have been used in the protection against median hazards

such as crash cushions, open guardrai ls, and closed guardrai l envelopes. Bridge piers are often

treated by surrounding them with rigid barriers and placing crash cushions on each end. Tlus

alternative is vet)' sh01t and therefore reduces the number of run-off-road accidents to a min imUill.

Unfortwmtely, this type of treatment is very costly and therefore is hard to justifY for most median

situations. Another J:Opular treatment involves using open guardrail envelopes. This design

incorporates long runs of guardrai l upstream from the hazards. Although tllis alternative is less

expensive than crash cushion designs, the long rw1s of guardrail generate many guardrail related

accidents, and when used in narrow medians, the backside of the guardrails can become a major

hazard. Enclosed guardrai l envelopes, called bullnose systems, involve wrapping the guardrail

completely around the hazards. These designs are smaller and therefore generate fewer guardrail

accidents. Further, bullnose designs are generally the least costly alternative. Unforttmately, bullnose

guardrail designs have never met current safety standards. This report describes an effort to develop

a new bullnose guardrail design that wi ll meet modern safety standards.

1.2 Objective and Scope of Design

The objective of this research project was to develop and evaluate a bullnose guardrail

system for the treatment of median hazards. nus research focused on the development of several

bullnose barrier concepts, the preliminary design of one concept, and the crash testing and evaluation

of the selected design. Subsequently, the crash test results wiU be used to aid in computer simulation

modeling as well as for redesigning the bullnose barrier for fi.tture compliance testing. The design

of the bullnose guardrai l system was conducted with a focus on safety, economy, reliability, ease of

construction, and main:enance. The bullnose guardrail was developed to meet the Test Level 3 (TL-

3) safety performance criteria provided in the National Cooperative Highway Research Program

(NCHRP) Report No. 350, Recommended Procedures for the Safety Performance Evaluation of

Highway Features (1).

Phase I of the design process, which is covered in this report, included two full-scale crash

tests which will later provide infonnation for redesign and computer simulation of the bullnose

barrier system. In order to complete the design and implementation of the bullnose barrier design,

a comprehensive set of full-scale compliance testing of the final bullnose design would have to be

perfonned. The preliminary developmental testing of the bullnose barrier consisted of two fi.tll-scale

crash tests. The first test used a 2000-kg pickup truck as an impact vehicle while the second used a

820-kg small car. Both full-scale tests were perfom1ed for a head-on impact with the bullnose at a

target speed and angle of 100 km/h (62. 1 mph) and 0 deg respectively. However, the small car test

was conducted at a 11..-point offset on the nose section. The test results were analyzed. documented,

and evaluated. Conclusions and recommendations were then made with regards to the safety

performance of the bullnose barrier terminal.

2

1.3 Previous d esigns

In past years, several studies have been undertaken to evaluate the performance of closed

guardrail median barriers or bullnose designs. These include studies by the Texas Transportation

Institute CIT!) on the Minnesota and Colorado bullnose proj ects (2:l) as well as a study by the

Southwest Research Institute, San Antonio, TX (4-5). The Minnesota and Colorado designs both

used w-beam as the rail element, while the Southwest Research Institute (SWRI) design used a thrie­

beam rail element. These three previous design concepts are shovm in Figures I through 3.

The crash testing of the Miru1esota design demonstrated good results, but the system was

evaluated accord ing to the criteria provided in NCHRP Report 153, Recommended Procedures for

Vehicle Crash Testing of Highway Appurtenances (2). The design met all criteria set forth at the

time. In general, crash testing of the Colorado design also showed good results , although the design

did have significant difficulty with a sedan impact at an angle. Specifically, the crash test which

impacted downstream of the nose of the barrier at a 25 degree angle did not effectively redirect the

veh icle. The safety criteria used in the Colorado design evaluation were from Recommended

Procedures/or Vehicle Crash Testing ojHighway Appurtenances (1). These criteria were satisfied

for all but the sedan test at a 25 degree angle mentioned previously. The SWRI study performed 16

crash tests based on criteria set forth in NCHRP Report 230 (]).All evaluation criteria were not met

for all tests. The researchers involved in this study concluded that bullnose barrier designs possess

a great deal of promise for treatment of median hazards, even though they were unable to

successfully develop a design that met all crash test safety standards.

In addition to the atorementioned studies pertaining to bullnose designs, several research

efforts were performed on another guardrai l system having a curved nose section of guardrail, such

3

as the short-radius guardrail system (9-14). The results of these research studies were also reviewed

in order to provide insight into the des ign of the new bullnose configuration.

The focus of this report was to investigate the feasibility of developing an improved bullnose

guardrail design. The following sections describe the design, testing, and evaluation of an new

bullnose barrier terminal concept.

4

Figure I. Minnesota Bullnose Barrier Design

5

NOTE: W-beam not attached at posts 2 and 4.

24"1il Concrete Pier Coble Anembly

1 5'-10 3/4"- -t- -- 6'-3" - - -+--

Po•t No.

I

I I I I ' --.: -. f- -,-~:.

- I I I

I I '---· -

1" Sill

2

o I --1:..- .. , ,.:::. .... ==~, I I I_ __ _J

Figure 2. Colorado Bullnose Barrier Design

..

3" Slit

t of Symmetry

6"xe'x6'·o· Post (Typ)

6"xe"xl4" Block (Typ)

I , --2'· 5"

-- 12°

6'- 2 3/4"·- --1---6'-3" (Typ)-~

I" Sill

4

I I I _ 1

I .,~ .. . ' ~ -: ... ~- ~ 1 I L __ J

5

'

~etric Conversions: 1 ft = 0.305 m 1 f n. = 2. 54 em

0 6 by a ., WOOO)'US IS ::I ' lly I ., WOOD ll.()Q(OUI S (!I CIIIWX:.lf'OSIS tJ OCIWOOOI'OGIS

NESIF.O liM liE llEMI 1.. l.j

~--------------------MIDGE flAIL

2S.fl·RAOIUS TIIRIE BEAM. ELIMIN.\TE CENTER HOLES IN THRIE BEAM TO MINIMIZE TEARING POTENTIAl=

T IIPER RAl. MOUNTING HEIGHT IN THE LAST SECTION OF THAIE OEAM IF TMNSITIONING TO A SAFETY·SHftPEO BRIDGE RAIL

WI.C by 22 OLOCKOUTS ON ALL BUlttiOSE POSTS

PLAN

7

ELEVATION

6 5 4 3 2

NOTES: SOUTHWEST RESEARCH INSTIT\ITE

1. No Bolls on be~m ol poSI 3 & 5 2. Use rectangut~r washers at posts ?l an1 2R.

GENEML PU\N & ElEVATION 2 Of II

Figure 3. Southwest Research Institute Bullnose Barrier Design

2 6 AH RIER DESIGN

2. 1 Rail Concepts

The initial design of the bullnose barrier began with a series of preliminary design concepts.

The prel iminary designs were divided by the choice of guardrail beam shape used in lhe design. The

fi rst set of preliminary designs were based on using a stacked W-beam guardrail that would faci litate

the capture of various size vehicles. The stacked W-beam barrier configurations proposed are shown

in Figures 4 through S. The W-bcam systems were designed to have horizontal slots cut in the valley

of the beam. The slots cut into the rail aid the beam in capturing the vehicle and help prevent the

vehicle from overriding or underriding the rail.

The other preliminary design concept was based on using a slotted thrie beam guardrail. The

thrie beam design allowed the usc of a single beam to catch different s ize vehicles. llorizontal slots

cut in the valleys of the thrie beam aid in the capture oftlte impacting vehicle. It was believed that

the s lots would prevent potential overriding of the guardrail by pickups and underriding of the

guardrail by small cars. Previous testing of short radius lhrie beam guardrails suggested that the use

of an unsloned rail would not be capable of capturing an impacting pickup truck and preventing

underride of a small car (1.1). However. the concept of using a thrie beam rail rather than multiple

W-beam ra ils allowed for a simpler design because connections and blockouts for only one beam

were needed.

The usc of a lhrie beam rai l simplified the bullnose design since it did not requi re the use of

a more complicated stacked W-beam rail. Titus. the bullnose barrier would be easier to constmct and

mamtam, and have lower overall construction material costs. Thus, lhe slotted thrie beam system

was chosen for further evaluation.

8

330 [)

312 ~ =========: ------ --- 312 ------ ---

b 50 675 50 675

D 312 ~ 840 --------- ------ --- 312 --------- ------ ---

330 b 25]

255 255

"' "' "' "' "' "' "' "' "'

Figure 4. Preliminary W-Bell!1l Bullnose Barrier Design Concepts

312 312

50 675 50 675

0 ••••• 0

312 312 0

230 230

Figure 5. Preliminary W-Beam Bullnose Barrier Design Concepts

2.2 Nose Sedion Design

The worst case scenario for bullnose guardrails is when they are used in a narrow median.

In this situation. the rail element is forced to bend through an angle of 180 degrees as the vehicle

progresses into the system. Thus, narrow systems subject the rail element to higher strains and as

a result cause higher vehicle decelerations. Therefore, after reviewing the Pooled Fund member

states' bullnose standards, a 4,500 mm design was selected for use in the cu1Tent study. The shape

of the nose section was chosen after analysis of prior bullnose (2-5) and short radius guardrail

designs~). The nose section was fanned using one I ,580-mm radius curved section of guardrail

with one I 0,400-mm radius curved section attached to each end of the nose section. The overall

shape was chosen us ing simple curves to simplify the design and fabrication of the rail. The curve

rad ii were sized based on ease of fabrication as well as to maintain the design width of the system.

The front-end section of the bullnose barrier was designed without a post at the centerline

of the nose. T he Minnesota and Colorado designs, mentioned previously, both used a post at the

centerline of the nose section that created problems during impact. The end pOSt tends to rotate back

after impact, creating a potential for vaulting of the vehicle over the rail. It was determined that a

nose section without the centerline post would have sufficient stmctural strength to maintain the

shape of the rail while not causing the vaulting hazard.

2.3 Fina l Bar rier Design Details

The complete layout of the bullnose barrier system used for the first test is shown in Figure

6. A one-halfba•,-ier system was designed for testing purposes to limit costs and time of construction

for the design. The bullnose barrier was 4,500-lllll1 wide by 20, 144-mm long. The system was

constructed with twemy-two wood posts with eleven posts positioned on each side of the system.

II

Bull-Nose 350 MBN-1

Test Test

Layout

+------21&0 tnfl'l moln tlot. o.rot..-.d. •"" ·- .,..., "'*" 2$ tM'I '*-

fUS80-

-------------------------------------~ -----------------

Figure 6. Bullnose Barrier Design Layout

The first two posts on each side of the system were 140-mm wide by 190.5-mm deep BCT

(Breakaway Cable Terminal) posts set in foundation tubes with soil plates and ground line channel

strut. Post no. I on each side of the barrier used no blockout wiJ.i. le post no. 2 on each side used a

200-mm deep by 150-nml wide by 554-nml long thrie blockout. The next seven posts along both

sides of the bullnose barrier are standard 200-mm deep by 150-mm wide by I ,980-mm long wood

posts spaced 1,905-mm apart as shown in Figure 6. Each of these posts uses a 200-mm deep by 150-

mm wide by 554-mmlong th1ie blockoutto space the rail away from the post. The top mounting

height of the rai l was 804 mm as measured from the ground surface. Posts nos. 3 through 9 had a

soil embedment depth of I, 153 mm. The last two posts on each side of the bullnose ban·ier were 140-

mm wide by 190.5-mm deep BCT posts set in foundation tubes without soil plates but with a

ground line channel strut.

A modified ground strut, shown in Figure 7, between posts nos. I and 2 on each side of the

system was designed to compensate for the curve of the nose section. The ground strut was altered

by angling the upstream yoke of the stmt 12.2 degrees.

A cable anchor system was used between the first and second posts on each side of the

system to develop the tensile strength of the thrie beam guardrail downstream of the post no. 2. A

reverse cable anchor system was used between post nos. I 0 and I I to replicate the rail strength of

an actual installation. TlJ.i.s setup was used for testing purposes only in order to simulate the effects

of a complete bullnose barrier terminal system with both halves connected.

The guardrai l used throughout the bullnose barrier consisted of 12-gauge steel thrie beam.

The eleven 3,8 1 0-mm long sections of thrie beam were spliced together with a standard lap splice

on each end of the section. The nose section of the rail consists of a 3,810 ITUU long section of

13

""mm ,.....,1 I I

100 mm

__ l_ __ _

Yoke

1----------- 1691 nvn ----------~f- 4 mm

C150x12..2 ChOnneol Section

1.5"

12.2"

... """ JJ mm l-----------1~2mm----------~

Strut

5mm

Assembly

NOTE: Strut cs shown for one side of the system, for other side the m irror image is required.

Figure 7. Modified Groundline Strut

14

12-gauge thrie beam bent into a I ,580 nun radius, as shown in Figure 8. The nose section is cut with

slots in the valleys to aid in vehicle capture as shown in Figure 9. There are six 700-mm slots

centered about the midspan of the rail, three in each valley. Each of the slots is separated by a 25-mm

gap. In addition. eight smaller 230-mm long slots, four on each end of the rai l section, are also cut

with a 50-mm gap betvveen them. All slots are 25-mm wide.

The second rail section on each side of the bullnose system is bent to form a I 0,400-mm

radius curve, as shown in Figure 8. These sections are cut with different slot patterns, as shown in

Figure 10. The fi rst two slots on each end are cut 290-mm long. The fourteen s lots in between are

each cut 300-mm long. A I 00-mm gap separates each slot. The eight remaining rail sections of the

system consist of standard 12-gauge thrie beam spliced together at the ends.

Photographs of the assembled bullnose barrier system are shown in Figures II through 12.

15

1580 mm radius

Top View, Rai l #1 ~End Section

[ 10400 mm radius

~ ~~.~~======~~~~~·~ Top View, Ro il #2

~ End Section

3810 mm, 12 gage, typ ica l thrie beam section

&­c

1---------3810 mm ---------1

Front View (unbent)

Figure 8. Layout of Bullnose Rails No. I and 2

~End Section

~:2 ~ 00 ,..: "'"' ~ n ~

.. ., "' ... 0> N «>- "'

., "' 0 "'"' 0 ..., ... " ~ 0 - ... "' < -- N NN "' f-244-f-2<6-

,_ I

~ ~

~ ~ ~

\ Splk-t Ovetlop Une "'-• 25 mm (typlc:ol)

Roil Section 1 ("Nose'' Section, MBN-1)

50 50 - 2-'0- - 230- 700 -=1

i Q Q Q Q

Q Q Q Q

Q Q Q Q

0 0 0 0

\_ SP'Iet Overlap line \All odditioi'IOI slOts 2$ mm

1

in widt.h

3733

Roil Section 1 ("Nose" Section, MBN-1)

Figure 9. Rail Section No. 1 Detail

0

0

:1 0 N ... "' 0>

0>

0 N "' 0> ... 0

N 0> "' 0> -N

0

~ N

0 N ... N

"' 0> 0> N

0 N

"' "' 1-18- - 2&M- H:l· - m.o- H:l· -21~.0- H:l· -m.o- -!:l· -m.o- - !:l· - m.o- -!:l·l- 27~.o- -~·l-27~.o- -!:l -t-m.o-Hz-I

0 0 0

0 0 0

0 0 0

0 0 0

~pli<e Overlap Une "'-• 25 mm (typico1)

1

3792.0

Rail Section 2 (MBN-1)

00

0

8 l--290.0 - 300.0 - JOO.O - JOO.O - -

I I 0 0 0

0 0 0

0 0 0

0 0 0

\.Spike Ov.rlop Une \_ AJe O<Sditionol •lots 25 mm in1

width

3792.0

Rail Section 2 (MBN-1)

Figure I 0. Rail Section No. 2 Detail

0

0

0

0

0

0

0

0

Figure ll. Bullnose Barrier Design

19

3 PERFORMANCE EVALUAT ION C RITERIA

3.1 Test Requirements

Terminals and crash cushions. such as bullnose barrier terminals. must satisfY the

requirements provided in NCIIRP Report No. 350 (1) in order to be accepted for usc on new

construction projects or as a replacement for existing barriers not meeting current safety standards.

The bullnose barrier terminal is defined as a gating device and must fulfil l the requirements for

gating tenninals. A gating device is one designed to allow controlled penetration of the vehicle when

impacted between the beginning and the end of the length of need. According to NCIIRP RepOrt No.

350, terminals and crash cushions must be subjected to seven full-scale vehicle crash tests. four using

a 2000-kg pickup truck and three using an 820-kg small car. The required 2000-kg pickup truck

crash tests for a Test Level 3 (TL-3) device are: (I) Test 3-31, a I 00 km/h impact at a nominal angle

ofO degrees on the tip of the barrier nose; (2) Test3-33, a 100 km/h impact at a nominal angle of

15 degrees on the tip of the barrier nose; (3) Test 3-35. a I 00 km/h impact at a nominal angle of 20

degrees on the beginni'lg of the LON (Length-of-Need); and (4) Test 3-39. a 100 kmlh impact at a

nominal angle of20 deg on a pOint at the length of the terminal divided by two. The required 820-kg

small <:.'\1' crash tests for a TL-3 device are: ( I ) Test 3-30, a 100 kmlh impact at a no1ninal angle of

0 degrees on the tip of the barrier nose with a I /4-point offset; (2) Test 3-32, a I 00 km/h impact at

a nominal angle of 15 degrees on the tip of the barrier nose; (3) Test 3-34, a I 00 km/h impact at a

nominal angle of 15 degrees on the CIP (Critical Impact Point). A diagram showing the impact

location for the seven crash tests is shown in Figure 13.

As previously mentioned. only two full-scale crash tests were conducted for this repOrt. tests

3-30 and 3-31. These two tests were run as a preliminary safety evaluation of the bullnose barrier

21

·-----------------------------·-·-·-

'"" I

·-·-·-·-----------------------·-·-·-C,I,P, (TIO)

Figure 13. Proposed Full Scale Crash Tests for Bullnose Barrier Evaluation

tenninal concept. The primary goal was to demonstrate that the new concept could capture both light

trucks and mini-size vehicles. The results from these two tests would be used to obtain information

for calibration of computer models, evaluate the feasibility of the design concept for the other

required impact conditions, and obtain information for future design modifications and

improvements.

3.2 Evaluation Criteria

Evaluation criteria for full-scale veh icle cr-dSh testing are based on three appraisal areas: (I)

structural adequacy; (2) occupant risk; and (3) vehicle trajectory after collision. Criteria for structural

adequacy are intended to evaluate the abi lity of the te1minal to contain, redirect, or allow controlled

veh icle penetration in a predictable manner. Occupant risk evaluates the degree of hazard to

occupants in the impacting veh icle. Vehicle traj ectory after collision is a measure of the potential

for the post-impact trajectory of the veh icle to cause subsequent multi-vehicle accidents, thereby

subjecting occupants of other vehicles to undue hazard or to subject the occupants of the impacting

vehicle to secondary collisions with other fixed objects. These three evaluation criteria are defined

in Table I . The full-scale vehicle crash tests were conducted and reported in accordance with the

procedures provided in NCHRP Report No. 350.

23

Table I . NCI-IRP RepOrt 350 Evaluation Criteria for 2000? Pickup Truck (Test 3-31) and 820C Small Car (Test 3-30)

Structural C. Acceptable test article performance may be by redirection, controlled Adequacy penetration, or controlled stopping of the vehicle.

D Detached elements, fragments or other debris from the test article should not penetrate or show potential for penetrating the occupant compa11ment, or present an undue hazard to other traffic, pedestrians, or personnel in a work zone. Deformations o f, or intrusions into, the occupant compartment that could cause serious injuries should not be permitted.

F. The vehicle should remain upright during and after collision although moderate roll, pitching, and yawing are acceptable.

Occupant H. Occupant impact velocities should satisfy the following: Risk Occupant Impact Velocity Limits (m/s)

Comuonent Preferred Maximum Longitudinal and 9 12 Lateral

I. Occupant ridedown accelerations should satisfy the following: Occupant Ridedown Accelerat ion Limits (G's)

!:;QillJ20nent Preferred Maximum Longitudinal and 15 20 Lateral

K. After coll ision it is preferable that the vehicle's trajectory not intrude Vehicle into adjacent traffic lanes.

Trajectory N. Vehicle traj ectory behind the test article is acceptable.

24

4 T EST CONDITIONS

4.1 T est Facility

The testing f<~cil ity is located at the Lincoln Air-Park on the NW end of the Lincoln

Municipal Airport and is approximately 8.0 km NW of the University ofNebraska-Lincoln. The site

is protected by an 2.44-m l1igh chain-link security fence.

4.2 Vehicle Tow and Guidance System

A reverse cable tow system with a I :2 mechanical advantage was used to propel the test

vehicles. The distance traveled and the speed of the tow vehicle are one-half that of the test vehicle.

The test veh icle was released from the tow cable before impact with the bullnose barrier. A fifth

wheel , built by the Nucleus Corporation, was located on the tow vehicle and used in conjunction

with a digital speedometer to increase the accuracy of the test vehicle impact speed.

A vehicle guidance system developed by Hinch (.12) was used to steer the test veh icle. A

guide-flag, attached to the front-left wheel and the guide cable, was sheared off before impact. The

9.5-mm diameter guide cable was tensioned to approximately 13.3 kN, and supp011ed laterally and

vertically every 30.48 m by hinged stanchions. The hinged stanchions stood upright while holding

up the guide cable, but as the vehicle was towed down the line, the guide-flag struck and knocked

each stanchion to the ground. The veh icle guidance system was approximately 457 .2-m long.

4.3 Test Vehicles

For test MBN-1, a 1989 Ford F-250 %-ton pickup truck was used as the test vehicle. The test

ine1tial and gross static weights were 1,998 kg. The test vehicle and vehicle dimensions are shown

in Figure 14.

For test MBN-2, a 1988 Ford Fest iva compact car was used as the test vehicle. The test

25

Do. te• 7122197 Test NuMber• MBN- 1 Model• E -250

Mo.ke• fORO Vehicle I. D. »• _...!1.t.f.J.TnHEw2~5;LY!..!4i!K>.LL.J.A!.>3!!;6tj4~8!J..I _ __ _

Tire Size• 235/85 R16 Yeo.r• 1989 OdoMeter• __,6..,5"'4,_9zc9z_ ___ _

•<All Meo.sur eMents Refer to !Mpo.ctlng Side)

Vehicle GeoMetry - Ml'l

0. 193Q.4 b 1854.2

' !0> c 5334,0 d 12 065

T L__j [:::::J

I

' t n -- 1'1 0.

l_ ,---, [:::::J j_

e 3390.9 f 736,6

h 1485,6 9 738,4

431 8 j 7366

\ k 438.15 654,0 )....- o.cc~lj?r"OMI?ters

M 1670 0 n 1632 0

I / ~\ Tire dro. I _,:_

Yl (

-~ ~ b ~ Jl 0

~ .-\@) 9 tv' ~~1Jf tl k1 Sl

0 1219.2 p 44.45

q 793,75 r 4445

s 5207 t 1930 4

f-- h - "' heel Center Height front 368.3

l--ei f -

\Jvreo.r e

'Wf'ronD "' c "'

heel Center Height Reo.r 381.0

heel 'Well Cleo.ro.nce (fR) 882.65

'Wheel 'Well Cleo.ro.nce <RR) 965.2

Engine Type S!Rlllui::II f> CYL 'Weights - kg Cur b Tes t lnertlo.l Gross Sto. t ic Engine Size 300 lnA3

'Wfront ll~Q 11~:3 11~:3 T r o.nsMiSSion Type•

'«'reo.r Elf>~ 67:5 az:s ~or Mo.nuo.l

"'toto.l l~fl~ ~~~a ~~~a E'WD or 8 o r 4'WD

Note o.ny do.Mo.ge pr ior to test• Minor f'loorboo.rcl deforMo.tion o.ncl dents on drivers side.

Figure 14. Vehicle Dimensions, Test MBN-1

26

inertial and gross static weights were 886 kg. The test vehicle and vehicle dimensions are shown in

Figure 15.

The Suspension Method was used to determine the vertical component of the center of

gravity for the test vehicles. This method is based on the principle that the center of gravity of any

fi·eely suspended body is in the ve1tical plane through the point of suspension. The vehicle was

suspended successively in three positions, and the respective planes containing the center of gravity

were established. The intersection of these planes pinpointed the location of the center of gravity.

The longitudinal component of the center of gravity was determined using the measured axle

weights. The location of the fi nal centers of gravity are shown in Figures 14 through 15.

Square, black and white-checkered targets were placed on the vehic le to aid in the analysis

of the high-speed fi lm, as shown in Figures 16 through 17. One target was placed on the center of

gravity on the dri ver's side door, the passenger's side door, and on the roof of the vehicle. The

remaining targets were located for reference so that they could be viewed from the high-speed

cameras for fi lm analysis.

The fi·ont wheels of the test vehicle were aligned for camber, caster, and toe-in values of zero

so that the vehicles would track properly along the guide cable. Two 58 flash bulbs were mounted

on both the hood and roof of the vehicles to pinpoint the time of impact with the bullnose barrier on

the high-speed fi lm. The flash bulbs were fued by a pressure tape switch mounted on the front face

of the bumper. A remote controlled brake system was installed in the test vehicle so the vehicle

could be brought safely to a stop after the test.

27

Do.te: 7/25/97 Test Nunber• ~M~B~N~-~2 ______ _ Model: FEST!VA

Mo.ke: ~F~O~R~DL--------­

Tire Size• 145 Rl2

Vehicle I.D.II• KNJBT06K4JBI25183

Yeo.r• 1988 Odoneter• 125473

Vehicle Geonetry - MM

L-J ~\ 0. 1:274.6 b 141;!1;!,1

·- <i vente e

n t c J:i!l:i 2 d :2:26.6

~r ::... e 1;!1;!26.7 f fl!IZ.Z

g :2!12.1 h 661;!.2:2

:lfll.Q j :i:l2.Z:i

k :l:;i:;i.2 ::i2Q,Z

M 1J2Q.2:2 n l:l64.J

0 722,Q p 72,2

q :227.Q r JJQ.;;:

s 272A t 1574.6

height of wheel ~47.2:2 center

Engine Type STRA1!:iHT 4 !;;YI..

Engine size Velght - kg Curb Tes t Gross Tro.nsnlsslon Type: lnertlo.l Sto.tlc

'-'front 46:2 :iQ1 :i:l7 Autono.tlc or~ 8or RVD or 4VD

'-'reo.r 266 3!Q 350

'-'toto.t Z:iJ 6ll !l!l2

Do.no.ge prior to test: front grill broken. front bunper bent

Figure 15. Vehicle Dimensions, Test MBN-2

28

--+- -- c -----~- 1

I--- h ----~--

TEsT #: _ _!._M!....,!:B::.J..._N.!......._,!l'--_

TARGET GEOMETRY (MM)

0. 876.3 b 635.0 c 2578.1 cl 1803.4

e 1695.5 f 1695.5 g 844.5 h 1492.3

1905.0 j 1066.8 k 717.6 l 1130.3

Figure 16. Vehicle Target Locations, Test MBN-1

29

Top View

a -t--- d - ---1

Sicle View

-----<~~-- g -----1

TEST #: MSN - 2 TARGET GEOMETRY (mm)

a 11 30.3 b 127.0 c 273.0 d

e 660.4 f 882.6 g 1416.0 h

536.6 J 658.8

Figure 17. Vehicle Target Locations, Test MBN-2

30

1130.3

698.5

4.4 Data Acquisition Systems

4.4.1 Accelerometers

One triaxial piezoresistive accelerometer system with a range of ±200 G's was used to

measure the acceleration in the longitudinal, lateral , and vertical directions at a sample rate of I 0,000

Hz. The envirorunen:al shock and vibration sensor/recorder system, Model EDR-4M6, was

developed by Instrumented Sensor Technology (1ST) of Okemos, Michigan and includes three

differential chrumels as well as three single-ended channels. The EDR-4 was configured with 6Mb

of RAM memory and a 1,500 Hz lowpass filter. Computer software, "DynaMax I (DM- 1 )"and

"DADiSP" were used to digi tize, analyze, and plot the accelerometer data.

A backup triaxial piezoresistive accelerometer system with a range of ±200 G's was also used

to measure the acceleration in the longitudinal , lateral , and vertical d irections at a sample rate of

3,200 Hz. The envirorunental shock and vibration sensor/recorder system, Model EDR-3, was

developed by Instrumented Sensor Technology (1ST) of Okemos, Michigan. The EDR-3 was

configured with 256 Kb of RAM memory and a I, 120 Hz lowpass filter. Computer software,

"DynaMax I (DM-1 )"and "DADiSP" were used to digitize, analyze, and plot the accelerometer data.

4.4.2 Rate Tn1nsducers

A Humphrey 3-axis rate trru1sducer with a mnge of250 deglsec in each of the three directions

(pitch, roll , and yaw) was used to measure the rates of motion of the test vehicle. The rate transducer

was rigidly attached to the vehicles near the center of gravity of the test vehicle. Rate trru1sducer

signals, excited by a 28-volt DC power source, were received through the three single-ended

channels located externally on the EDR-4M6 and stored in the internal memory. The raw data

measurements were then downloaded for rumlysis and plotting. Computer software, "DynaMax I

31

(DM- 1 )" and "DADiSP" were used to digitize, analyze, and plot the rate transducer data.

4.4.3 High Speed Photography

For test MBN-1, seven high-speed 16-mm Red Lake Locam cameras, with operating speeds

of approximately 500 frames/sec, were used to film the crash test. A Locam, with a wide-angle 12.5-

mm lens, was placed above the test installation to provide a field of view perpendicular to the

ground. A Locam, with a zoom lens, was placed downstream from the impact point and had a field

of view parallel to the barrier. Two Locams, with zoom lenses, were placed on both sides of the

barrier at the nose and had a field of view perpendicular to tbe barrier. A Locam was placed 9.14 m

upstream and offset 19.81 m to the east for a view of the front of the barrier. The two remaining

Locams were placed 6.4 m and 37.8 m downstream and offset 12.19 m and 21.34 m to the left,

respectively, to provide additional viewing angles of the crash test. A schematic of all seven camera

locations for test MBN-1 is shown in Figure 18. For test MBN-2, the exact same high-speed camera

setup was used as test MBN-1. A schematic of the seven high speed camera locations for test MBN-

2 is shown in Figure 19. The film was analyzed using the Vanguard Motion Analyzer. Actual camera

speed and camera divergence factors were considered in the analysis of the high-speed film.

4.4.4 Pressure T ape Switches

For tests MBN-1 and MBN-2, four pressure-activated tape switches, spaced at 2-m intervals,

were used to determine the speed of the vehicle before impact. Each tape switch fi red a strobe light

which sent an electronic timing signal to the data acquisition system as the left front tire of the test

vehicle passed over iL Test vehicle speeds were determined from electronic timing mark data

recorded on "EGAA" software. Strobe lights and high-speed film analysis are used only as a backup

in the event that vehic:e speeds cannot be determined from the electronic data.

32

- - 6.40 m

Locom r #2 1~ 12.1 9 m

I 7.01 m

Locom #6

, f SVHS #1

.....----+-- V"":":, Oh Locom ·( 15.01 m)

1---=

21.33 m

1-------- 37.80 m - -------;

16.76 19.81 m l l----------- 64.32 m --

• I~ Locom #7

Locom #1

~ SVHS #2 Panning

I- 9.14 m -

Figure 18. Location of High-Speed Cameras, Test MBN-1

mm

Locom #5

... SVHS #3 ... DC Locom #4

- f- 6.40 m

Locom #6

' ~ SVHS #1

r~ Locom #2 1111 I' 12.1 9 m

I 7.01 m

-.------+-- 1~ Oh Locom ' (15.0 1 m) I~

21 .33 m

f-------- 37.80 m ---------1

16.76 19.8 1 m

l f------------- 64.32 m

lr

~ Locom #7

Locom #1

I SVHS #2 Panning

9.1 4 m-

Figure 19. Location ofHigh-Speed Cameras, Test MBN-2

mm

Locom #5

.... SVHS #3 .... DC Locom #4

4.4.5 Strain Gauges

For test MBN-1, four strain gauges were installed on the thrie beam guardrail, consisting of

four gauges located on the back side of the thrie beam rail. The strain gauge positions and a

photograph showing the gauges on the bullnose barrier terminal are shown in Figure 20. Strain

gauges were not used in the instmmentation for the small car test, MBN-2.

For the tests, weldable strain gauges were used and consisted of gauge type LWK-06-

W2508-350. The nominal resistance of the gauges was 350.0 :1: 1.4 ohms with a gauge factor equal

to 2.02. The operating temperature limits of the gauges was -195 to +260 degrees Celsius. The strain

limi ts of the gauges were 0.5% in tension or compression (5000 IJ.€). T he strain gauges were

manufactured by the Micro-Measurements Division of Measurements Group, Inc. of Raleigh, North

Carol ina. The installation procedure required that the metal surface be clean and free from debri s and

oxidation. Once the surface was prepared, the gauges were spot welded to the test surface.

A Measurements Group Vi shay Model 23 10 signal conditioning ampl ifier was used to

condition and amplify the low-level signals to high-level outputs for multicharmel, simultaneous

dynamic recording on 'Test Point" software. After each signal was amplified, it was sent to a Keithly

Metrabyte DAS-1802HC data acquisition board, and then stored permanently on the portable

computer. The sample rate for al l gauges was 5,000 samples per second (5,000 Hz), and the duration

of sampling was 6 seconds.

35

Tabk 2. Strain Gauge Locations

I STRAlN GAUGE INSTRUMENTATION I Gu ugc Loc:rtion Position Distance

I Top - Middle Hump-Neutral 4" Upstream of Post II I Edge Axis - Oack Side 7" Upstream Post # I CL

2 Bottom - Middle Hump- 4" Upstream of Post II I Edge Neutral Axis - Back Side 7" Upstream Post # I CL

3 Top- Middle Hump-NeUiral Midspan Between Posts 114 Axis - Back Side and #5

4 Bottom- Middle Hump- Midspan Between Posts #4 NcutmJ Axis - Back Side and #5

figlltC 20. Str!lin liauge Locations, Test MAN-I

36

5 CRASH TEST MBN - 1

5.1 Test MIJN-1.

Tbt: 1998-kgpickup truck impact.:d the bullnos.: barrier terminal at a speed of 101 .4 km/h

aml an angle ofO. l dt:gret:S, as shown in Figun: 21. A stmunary oCthe test results !utd llu: sequt:ntial

photogmphs are shown in Figure 22. Atldit ional sequential photographs are shown in Figure 23.

5.2 Test Oesca;pt ion

f-ollowing tbtl initial impact with the pickup truck, the thric beam rai l immediately began to

deform inward. At 0.064 SI:!C aner impact, post no. l on both sides of the barrier fractured and the

front 'Juarter or the:: truck pw1etmted into the:: bullnose. The slolled thric beam flanened acaoss the

front of the truck 'apturing the bumper and 14rill of the truck. A large "knee" or kink forrncd in the

rail on the lell side of U1.: barrier between post nos. I and 2 al 0. l l sec after impact. As the truck

continued to penelrdte the barrit~r, post no. 2 on both sides of the barrica failed at 0.18 sec aftca·

impact. At tllis point, the fumt oftht~truck w<ts t:Vtlrl willa post no. 3. 1h~ thrjc beam srtagged at post

no. 3 on Ute right side of the barrier at a lime of 0.31 ~ec alter impact causing Uae tbrie beam to

rupture. At this time, the velocity of the pickup truck was 75.7 krn/br. This allowed the tn1ck to

continue traveling forward in the middlt: r.:gion of the barrier. At lime 1.20 sec aFter impact, the

U'Uck impacted and !ractured post no. 7 ontht: lefl side of lhe barrier as it exited the system. Figure

24 shows the trujectory of U1e pickup tluring the crash lest.

5.3 Vehicle Damage

Vehicle damagt: WiiS moderdte, as shown in Figure 25. The fr011t bumper and front end of the

truck were ' rushed inward. "111.: right-front render ofthc pickup truck wa5 cru5hed out-wmd due to

the barrier impact. ll1e luwt:r section of the right door was slightly crushed inward. The left-front

37

fender of the truck !:howed some damage but there wa~ 110 damage to the left-side door. There was

no crushing of the pickup truck's occupant compartment The front tire on the right side was

detached from the rim during impact. Finally. the bolt mount~ on the transmission were sheared off.

5.4 llan ·icr Damage

Barrier damage was extensive. as is shown in Figures 26 through 27. All fottr of the BCT

posts used in the barrier fractured at the hole near the base of the post. Post no. J on both sides of

the barrier wJs also broken. Post no. I I on the len side of the barrier was contacted :md broken as

the tn1ck exited tlu-ough the middle ofthe barrier. The thrie beam buckled :md bent at post no. Jon

both sides of the barrier. The thrie beam also buckled at post no. 4 on the led'\ side of the barrier.

The tbrie beam tore at two locations during the impact. The first tear occurred 229-mm

upstream of post no. I on the left side. The tear reached [rom the top of the beam to the slot in the

lowest valley of the beam. The second tear in the tbrie beam occurred 762-mm upstream of post no.

I on tbe right side. The tear was located bctw~.:en the valleys of the. beam.

5.5 Occupant l~isk V:tluc~

The nonnaliwd longitudinal occupant impact velocity (OlV) was detcnn.incd 10 be 4.83 m/s.

The maximum 0.0 I O-see average occupant ridedown deceleration (ORO) in the longitt~dinal

direction was 9.95 g's.1l1c latcml OIV and ORO limits were not dctcrmi11Cd due to the absence of

contact between a hypothetical occupant and the side of tlhc vehicle. It is noted tl1at tlhc occupant

impact velocities and occupant ridcdown decelerations were within the suggested limits provided

in NCHRP Report No. 350. The resu lts of the occupnnt risk dnttl nrc summarized in figure 22.

Results arc shown graphically m Appendix /\.

J8

5.6 Discussion

Following lest MBN-1. <1 satety performance evaluation wus conducted, and the bullnose

barrier design was determined lu be unacceptable according to NCHRP Report No. 350 criteria. TI1e

bullnose barrier did not ~:ontain or stop the test vehicle in a controlled manner due to the fracture of

the thrie beam during the impact. llowever, it should be noted that the pickup tmck did not override

Ute U1rie beam during the imp<lcl prior to lht: thrit: beam frc~~.:ture. Detached elements and debris from

Ute test article tlid uol pt:nt:trate or show potential lor penetrating the occupant compartment. There

was no deform<•lion o~ or intrusion into, tht: occupant compartment that could have caused serious

injury. ·n1e vehicle remaint:d upright during and afier collision and the vehicle's trajectory did not

intrude into al!jm:enl traffic lunes. Vehi.cle Ln~jectory behind the test article was una\:Ct:ptable as the

test vehicle pcm.:l rated iluough 1 be barrier and imo the median area behind the bu II nose. The

occupant impact velocities a1\d ridedown accelerations were wiLhinl11e suggested limits imposetl by

NCHRP Report No. 350.

Tht: failure uftl1e system 10 meet all of the safety perfonnanc~ criteria wa:; directly attributed

tu th~ fmcture uf lbe lhric beam. Tho.: caus,.;s of the lluit: beam fracture were invesligllted for

corrccl'ion in lt llurc designs. The t11rie beam fractu1·e occurred when the rai l wrapped around post M .

3 on the rir,:ht side of the batTier. When the post did not fracmrc, the thrie beam was pu lled tight

while bending, thus creating large stressc~ in the thrie beam at high strain rates ultl•11ately causing

the thrie beam ll' fracture. The usc of weaker posts at post nos. 3 and 4 would allow t·he beam to

cotliinue 10 deform wi thout snagging on the po$t,~, preventing the large Sfi'C$$CS and ensuing beam

failure that occurred in test M8N-I .

39

•

5.713m..-ier lnstnnnentation Results

For test MBN-1, s1 rain gauges were located on the thrie beam rai l. The resu lts of the strain

gauge analysis are provided in Table 3. The data for strain gauges no. I and 2 was not used due to

evidence of yielding in the rail. The straitl gauges were defom1ed and the data would have been

invalid. Graphs ofrhe data taken from gauges11o. 3 ru1d 4 are located in the Appendix 8 (Figures B-1

and B-2).

110

41

~~··

. ··~~IlL I I r

0.00 sec

• 1 eS~ Number • Daie . ... • • App~nnncc .. •• • 1'ou11 LengJh • S1<>cl1ltrle Beam (Nc,;tcd)

"l'hicknds fop MOIUIU!Il\ l!ciJltl .. ,

• Wood l'osl>

......

I'm I Nos. I • 2, 10 • I I ( IJC'I ) I'O>I Nos. 3 • 9

• Wood Spacer Blocks PO>I '110<1 I • 8

• So1I Typ: • Vehicle Model .. . ..

Curb 1'C>tln::nool Gross S~a<oc

• Velude Spe<d ~ Elcl

.... ... ...

MIJN-1 71221'!7 Bullnose Median llnrricr

. 20.144 rnm

• 12 gouge (2.66 ntnll 80~ mm

I~CI mm ~ 190.5 mm • 1.080-mnolong 150 mm" 200 mm' 1,9&(knru !ong

1~0 ••m x 200 mn• x 554-mm long ()rod.nJ: B • t\ASIITO M 147-65 (1990) 1989 Ford 130 2WD 1.982 kg 1.998 Ls t.998ls

101 .4 kmltr 'it\

Figure 22. Summary and Sequential Photos, Test MBN-1

O.l 15s<t

• VehiCle Anr,lc lmJN!CI Gxll

• Vehicle Snagging . . , , • • Vehicle Slabilil} • Occupnnl R1dedo"n Deco!< ration ( 10 mscc :.vg)

U.ngiludinnl ..• l.mcrnl (nOI r"'!ulrcd) ••

• Occup•n• hnp.1<1 Velocll) f.'lormal!Ud\ Longiludlnal .. Latcrolcnol r<quitcd) •

• Vehicle ~age fAD SAE

• Vehicl< Sto;>J!ing OiSiwtce .

• ML•imunl Dc:1l<Ctl~ Permanent Sci 0)narnic: ..

....

... 0.1 deg

.... N,\dcg . ... None . .. Sausfaclory

.. .. 99Sg's )'lA

4.83 in/$

I' A Moderate 12-FD-1 12FDE\vS 24.69 m down.<tt<::\111 &.38m left of ccnlcrline rr """.,;, e 11111 clam:lg< :md ihe fract.wu1 pos~

.. NA ... NA

0.063 sec

().185 Sl:c

figw'C 23. AddiliOil& l Sequemiol Photographs. Test MON-1

43

23.1 6 m -------~· ~

9.45 m

Figure 24. Vehicle T~ajectory, MBN-1

Figure 25.

45

Figure 26. Barrier Dan1agc, Test

46

47

Table 3. Strain Gauge Data, Test MBN-1

Hnrdwarc Stmin Maximum Maximum Comments typo G<IUgc Nn. 11 Stmin1 S1rcsr

(lnJ in .) (ksi)

I NA NA Datu was llOIIftken because or yield or the rail at the gauge location

Thl'ie 13eam 2 NA NA Data was not take11 because of yield of the rail at the

snuse iocation

3 260 7806 Noue

4 421 12625 None

1- All stmin vulues ore shown ns the absolute value only '· All elnsuc strtSS \'a lues are <hown as the absolute value unly and culculutcd by multiplying the strain by the

mutluiW< ul'chosticity cqunlto 30.000 ksl. Mlnnnum yltld stress for the thrie beam is 50 ksl. NA· NCll Available

4ll

c; BARRJF.R MODIFICAT IONS (DESIGN FOR MDN • 2)

·n1c bullnose barrier tem1inal system was modified prior to conducting the second full-scale

cr.tsh to.:st, l~t MBN-2. An analysis of the test MBN-1 results revealed problems or flaws th<tt needed

tu l>c ICillctlicd prior to performing additional crash tests.

As p1cvinusly described. tho bullnose configuration used for test MBN- 1 was constructed

with stnndnrd 150-mm wide by 200-mm tleep timber guardrai l posts for post nos. 3 thmugll 9 on

each side. Also. the thrie beam rail sections on either side of the system did not contain any

ho1 iromal slot~ between post nos. 3 through II . ll1creforc, tbe relative strength of the guardrail

system was much higl:er downstream of post no. 3 versus the region upstream of post no. 3.

Dttri llf! test MBN-1. the first two posts on each side of the system trncturcd ns planned. and

the first two thrie beam segments buckled and dctormcd easily with lltc inclusion of the horizontal

slots. However. when the thrie beam rail dctormcd around post no. 3 on tJ1c right side ofthc system,

the post did not fulcture, resulting in high stresses and strains being induced into the lltric beam roil.

This high impulse loading led to the rupture of the thric beam rail on the right side of the guardrail

system without stopping the vehicle. In addition. even though post no. 3 on the ten side of the

system fulctured. another potential problem was revealed ns the sriffscgment ofthrie benm between

pMt nos. J and 4 was tlcformcd toward the leO side of U1e vehicle ns the vehicle penetmted the

bullnose system. Since ll1c thrie beam did not contnin slots for weakening the mil in this region. the

thrie beam kinked at post no. 4 and tonncd o knee ot post no. 3. This knee revealed the potential for

peneu-.lling or snagging on an impacting vclliclc although no actual vehicle contact occurred on the

len side of the system.

Although the thric beam fmctured during test MBN-1 and did not capture the pickup truck,

<19

the sloued tlu il: beam mi l prevented the pickup truck from ove1·riding tl1e no~e section of the ~ystem.

'l'he•'efor.:. tho: researchers believed that the sy~tem could be ~ignifieantly improved by weakening

the buckling 1111d bending strcJlgth of the thrie beam rail a . .fter post no. 3 as well a~ replacing post nos.

3 aud 4 wi th posrs :hnt would fracture more ea~ily. Following the failure of test MBN-1 ,

modi ficario.ns were made ro the guardrai l sy~tem. These modifications to the bullnose guardrail

system con~isted of changing of post nos. 3 :md 4 to breakaway posts and incorporating slots in

another ~ection of the tluie beam rai I. A schematic of the modi.fied design is shown in Figure 28, and

photographs nrc provided iu f:' igures 29 through 30.

For the fi rst modification, post no. 3 on each side of Lhe system was replaced by a 140-mm

by 190.5-mm BCT post set in a foundation tube wi thout a bearing plate, while post no. 4 on each

side wa~ replaced by a CRT post. These post changes were made to accek:ratc the fracture of the

posrs in those areas, prevent high loads being imparted into the thrie beam rail , and reduce the high

rail stresses from occurring at concentrated locations. These changes would a.lso allow for a more

gradual dissipation of the vehicle's kinetic energy.

The slot pattern for mil ~ectioo no. 2 on both side.s of the bul lnose barrier terminal was also

modified sl.ightly from the original design. The new slot pattern tor rail no. 2 is shown i.n Figure 32.

The slot pattern was changed to lorm eighteen 290-mm long slots, 9 in each valley. Each of the slots

is separated by a I 00-mm gap. The slot width remained 25 mm. The final major modification to the

bullnose ~ystem was the addition or slots to rai l section no. 3 on both sides of the system. The slot

pattern of ro:~ i l ~cction no. 3 is shown in Figure 33. Twelve 300-mm slots were cut out of tl1e valleys,

six in each valley. with 250-mm spaces between them. I he modification of the slots in section no.

2 and the addition of slots to section no. 3 serve to reduce the strength oftlte beam. Reducing the

50

Bull-Nose 350 Test Layout MBN-2 Test.

+------11)0 .. ~ 1111;\ c.. ..... ~to........_.-..-~- ...

------------------------------------ ..,.~, -----------------

""' Figure 28. Bullnose Barrier Design. Test MBN-2 L

Figure 29. OullnoliC De.sign for Tcsl MBN-2

52

53

g 00 r.: •. ,,., ~~

Oil')

i ; ... ..... N oo- ~~ "' ~ 0000 0 .., ... i 0 -- "" "'"' e- 1" -= ·-I

:II

~c.o.-,u ... "'-• 2S "'"' (!>*"I

I

Roil Section 1 ('Nose" Section, 'viBN-2)

f-130- ' I

~

~ ~

S¢1co o.. ........ \,., c<hitlcnol ..... 25 rrm

1

In • dll>

Roi Section 1 ('Nose" Section, MSN-2)

Figure 31. Rail No. I Decail Test. MBN-2

0

0

0

0

0

0

"l

"' 0 N 0

0 :;

0

"' N

~ 2650- ~+-••• o- 1-~-l- 265.0-l-~-l-265.0-l-~· l-265.0-l-~·

I

0

0

0 ' 0

~'!coo O..rtop Uoe "'-• 25 nvn (\)'olccl~ 3792.0

Roil Section 2 (MBN-2)

g 1290.0-+= 1+-,.90.0

§ 2so o-+= I+-1 ... o

<! ~ 0 l! 0 :: I

I I I

<!

,l! I I

\_~1 oddhionol alola 2.5 mm ~~ WSI~

l-265.0-l-~· 1-2•s.o- H!· "' co

l-265.0-• ,.,

~-;r·65.J) ~-t-

'

~ 0

0

0

0

~----------------------------------------3~2Jl•-----------------------------------------4

Roil Section 2 (MBN-2)

Figure 32. Rail No. 2 Detail Test, MBN-2

0

0

0

0

0

1265--r-27~127~127512751275--r-2651265,275,2751275127~1275--r-2651

0 - - 0

0 - 0

0 0

0 0 - -~. 25mm (lypiccl)

I

~----------------------------------------MIO----------------------------------------~

Roil Section 3 (MBN-2)

-JOO-l-2~- -300--l--2~-1--JOO-- -252.51 i

0 0 0 0

0 0 0 0

0 0 0 0

0 0 0 0

~•• O.erlop Line \_All Additionol Slott 2Smm in WidU'I

1

MIO

Roil Section 3 (MBN-2)

Figure 33. Rail No.3 Detail Test, MBN-2

strength of the beam will also allow the beam to deform more easily during impact, thereby

decreasing the high stresses created by the kinking action in the beam. The slots a lso aid in the

capture of the vehicle by allowing the beam to wrap around the vehicle during impact to prevent

overriding or under riding of the beam.

It was decided that the second test should be the 820-kg small car test as planned and not a

rerun of the fai led 2000-kg truck test. The project team wanted data for both a truck and a small car

because one of the major purposes of these initial tests was to verify that the slotted thrie beam could

capture mini-size vehicles as well as light trucks and provide data for computer simulation modeling

of the bullnose system. A rerun of the truck test would have limited the available data to the behavior

of the barrier in a truck impact only.

57

7 CRASH TEST MBN - 2

7.1 Test MBN-2

The 886-kg small car impacted the bullnose baJTier terminal at a speed of I 03.3 km/h and

an angle of -3.4 degrees with a 1/4-point offset A summary of the test results and the sequential

photographs are shown in Figure 35. Additional sequential photographs are shown in Figure 36.

Full-scale crash documentary photographs are shown in Figure 37 through Figure 38.

7.2 Test Description

The nose section of the bullnose ban·ier began to deform immediately after the initial impact

of the 886-kg small car. At 0.107 sec after impact, post no. I on both sides of the barrier failed and

approximately one half of the small car had penetrated the bullnose barrier. The slotted nose sections

of tlu·ie beam rai l wrapped around the front of the vehicle capturing the vehicle's bumper and grilL

After the failure of pOst no. I, the back of the vehicle began to rotate counterclockwise towards the

right side of the barrier. Post no. 2 on the right side of the barrier failed at 0. 196 sec after impact. A

rail "knee" or kink formed in the thrie beam on the right side of the barrier as the vehicle continued

to penetrate and deform the barrier. The knee impacted the right-rear quarter panel of the small car

at 0.282 sec after initial impact, deforming the right-side of the vehicle and shattering the rear

window. At 0.542 sec, the vehicle was brought to a complete stop. The vehicle trajectory is shown

in Figure 39.

7.3 Vehicle Oamage

Vehicle damage was ex tensive, as shown in Figure 40. The front end of the small car was

crushed, includ ing the bumper, engine compartment, hood, and front quru1er panels. The front

windshield was also fractured during the impact. The right-side sheet metal behind the door was

58

deformed inward approximately 12.7 em due to "knees" fotming in the thrie beam rail and impacting

the side of the vehicle. The righ t-side door was damaged a long its entire length, and the right-side

window glass was shattered. The left-side door was deformed and wedged shut at the front hinge.

Only minor floorboard deformation was found in the occupant compartment.

7.4 Barrier Damage

Barrier damage was extensive, as shown in Figure 41 through Figure 42. Post nos. I and 2

on each side of the system were completely fractured. The rail buckled during impact at post no. 2

on the left side o f the system and slightly upstream of post no. 3 on the right side of the system.

Significant tearing of the thrie beam occurred where the rail wrapped around the front end of the

small car. Tearing of the horizontal slots in the thrie beam occurred at several posts and where the

rail buckled near the posts nos. 2 and 3. In addition, tearing of the slots occurred at some midspan

locations. Deformations to the thrie beam occurred to the nose piece as well as rail section no. 2 on

both sides of the system. The deformed shape and deflection of the barrier is shown in Figure 43.

The maximum permanent rail deflection was 7. 11 m.

7.5 Occupan t Risk Values

The normalized longitudinal and lateral occupant impact velocities (01 V) were determined

to be 9.60 m/s and 3.27 m/s respectively. The maximum 0.010-sec average occupant ridedown

decelerations (ORD) in the longitudinal and lateral directions were 11.37 g's and -9.98 g's

respectively. It is noted that the occupant impact velocities and occupant ridedown decelerations

were within the suggested limits provided in NCHRP Report No. 350. The results of the occupant

risk, determined fi·om the accelerometer, are stumnarized in figure 35. Kesults are shown graphically

in Appendix A.

59

7.6 Discussion

Following test MBN-2, a safety performance evaluation was conducted, and the bullnose

batTier design was determined to be acceptable for Test 3-30 according to NCHRP Report No. 350

criteria. The bullnose barrier contained atld stopped the test vehicle in a controlled manner. It should

be noted that the thrie beatn captured the small car with no overrid ing or under riding of the rail.

Detached e lements and debris from the test article did not penetrate or show potential for penetrating

the occupant compartment. There was no deformation of, or intrusion into, the occupant

compartment that could have caused serious injury. The vehicle remained upright during and after

co ll ision and the vehicle's trajectory did not intrude into adjacent traffic lanes. Vehicle U<Jjectory

behind the test article was acceptable as the test vehicle did not penetrate tlu·ough the barrier and into

the median area behind the bullnose. The occupant impact velocities and ridedown accelerations

were within the suggested limits imposed by NCHRP Report No. 350.

It is noted that the actual impact angle of -3.4 deg was not within the allowable angle

tolerance of :1: 1.5 deg on a target impact angle of 0 deg, as provided in NCHRP Report 350.

However, the authors believe that this error accentuated the vehicular yaw motion induced by the

1/4-point offset, thus making the crash test a more stringent impact condition by increasing the

potential for rai l penetration in the side of the car.

60

figure 34. Impact Location Test MBN-2

Iii

0.00 sec

• rc:st Number . . • D:ue e ~\ppUrtC3laJ1CC

• Totnl Length .• • Steel Thri< Bum INcstl)tl)

Thickness .• . •. Top Mountin~ llct£ht •.

• Wood l'osts l'ost '<os. 1 • 3, 10 • I I (IICn Post No.4 !Cit l) Post Nos. l • 9

• Wood Sp:;c~r B.odcs Po>! Nu 1 • 8

• S"' I Typ.: • Vd!icle MoJcl

Curb . r o:st .. ..,,., Gross Swic . • •

• Vehicle Speed lmpoct E•it . .

• . MBN-2 .. 7f.!sm

0.107 sec

• llullnose Median Barrier . 20,144 m

• 12 aaugc (l.li(; ntm) .. 80~ mm

1~0 mm' 190.S mm' l.080-mm long I SO mm' 200 nm> >. 1,98Q..mm long ISO 111111 x 200 ntm >. 1,98Q..mm loog

150 nt·n x 200 n>m ' j$4-mm long . Omdirg B · AASHTO M 1 ~7-65 ( 19901 • 1983 rord Fcsti>a . lSJ k&

Sll kJ • 386 k&

. 103.3 .nnlhr • 0.0 Lm.'tr

Figure 35. Summary and Sequential Photographs, Test MBN-2

• Vc:hlclc Antle lmptct Exit

• Vehtclc Snagging •. • Vehicle Stnbilhy •

. ... I ' o I I ' o ' ' o

I o o o o o 1 o o o o o I o o o o

• Oocupam RidedoM> l),..,elcr"tion (It)'"'"" ••&-l LonGitudlnol .. . .. • ... Latcml (not required) • • • • • ••.

• U<etip:lllt lmpael Velocity (Nonnalitedl Lonsnudtnol l.ottrnl tnot rcqnircd)

• Vc:hfdc Datnage ·rAD S/,[

• Vchtdc Stoppint Di>w.:c

• Ma~unurn DeOcehors Pennancnt Set

Oyn:mic

-3.4 dcg NA ~one

Sa~l.fncl(>ry

11.37 !'• 9.091-9.98 g's

9.60 mls J ,27 mls :>loder:ttc 12-FD-5 11 3-RBQ-1 l lFOciVS lo'OJRBEK9 655 m downsmam 1..58 m >V<Sl ofcancrlmc E.XJensive rail damage and rour (rliCt\lred JlOS"..S

1 II m do"11Strcam 0 97 m "'"" of cent<rfmc ~A

0.105 set:

0.209 sec

'· . --. ,.. . ': . ... . \ ~-:'"•o· .. l~'\ ..... -rr.. ~ \r"";~·~ • t .... ..

' I ' I

0.275 SI.:C

0.477 sec

Figure 36. AdUitional Sequential Photographs. Test MBN-2

63

Figun: 37. Full-Sc<tle Cmsb Tcsr, MBN-2

64

Fii\Urt! 38. Full-Scale Crash Test. Test MBN-2

65

6.55 m

6.25 m

Figure 39. Vehicle Trajectory. Test MBN-2

67

61!

rigure 42. Oarrier Damage, Test MBN-2

69

~--------7l.12 M---------1

Figure 43. Permanent Rail Deflection, Test MBN-2

--------- ORIGINAL SHAPE DEFLECTED SHAPE

8 SUMMARY AND CONCLUSIONS

A bullnose median barrier terminal was developed and full-scale crash tested to evaluate the

initial design concept and to provide data for future design modifications and computer s imulation.

Two crash tests were performed accord ing to Test Level 3 (TL-3) ofNCH~P Report No. 350. A

summary of the safety performance evaluation is shown in Table 4. Test MBN-1 was conducted with

a 1998-kg truck, while test MBN-2 used an 886-kg small car. The first test, test MBN-1 , failed after

the thrie beam fractured resulting in an uncontrolled penetration of the vehicle behind the barrier.

llowever. the pickup truck did not show any potent.ial for override of the thrie beam. Following this

crash test, the bullnose barrier was modified to prevent the fracture of the thrie beam during impact.

The bullnose was modified by the addition of BCT posts at post no. 3 on each side, CRT posts at

post no. 4 on each side, and horizonta l slots in the valleys of rai l section no. 3. The second test, test

MBN-2, was performed on the modified barrier and was determined to be acceptable accord ing to

the TL-3 crash test criteria ofNCH~ Report No. 350. The small car did not show any potential for

underride of the thrie beam.

The phase I development of the bullnose barrier median treatment was successfully

completed. An initial design concept was developed and tested. The data gathered during the testing

provided valuable information that will be used in further modification and testing of the bullnose

design and in computer simulation of the bullnose ban·ier.

71

Table 4. Summary of Safety Performance Evaluation

Evaluation Evaluation Criteria Test Test Factors MBN-1 MBN-2

Structural c. Acceptable test anic le performance may be by red irection, controlled u s Adequacy penetration, or controlled stopping of the vehicle.

D. Detached e lements, fragments or other debris from the test artic le s s should not penetrate or show potentia l for penetrating the occupant companment, or present an undue hazard to other traffic, pedestrians, or· personnel in a work zone. Deformations of, or intrusions into, the occupant compartment that cou ld cause serious injuries should not be permitted.

F. The vehicle should remain upright during and after collision a lthough s s moderate roll, pitching, and yawing are acceptable.

Occupant H. Occupant im pact velocities should sat isfy the following: s s Risk Occupant I mpact Velocity Limits (m/s)

!:;QWI!QD~DI Preferred Maximum Longitud inal and 9 12 Lateral

I. Occupant ride down accelerations shou ld satisfy the following: s s Occupant Ride down Acceleration Limits (G's)

(;;Qm(2Qnent Preferred Maximum Longitudinal and 15 20 Lateral

K. After collision it is preferable that the vehicle's trajectory not intrude into s s Vehic le adjacent traffic lanes.

Trajectory N. Veh ic le trajectory beh ind the test article is acceptable. u s

S - (Smisfactory) U -(Unsatisfactory)

9 RECOMMENDATIONS

The bullnose barrier med ian treatment described in this report was successfully tested for a

820C small car in a head-on impact at the Yo-point of the vehicle. The results of that test demonstrate

that there is significant potential for further development of the bullnose concept. Thus, it is

suggested that the research described herein be further developed us ing the data collected from

testing to modify future designs and to aid in computer simulation of future designs. In addition,

with only minor modifications to the design used for test MBN-2, it may be possible to successfully

capture and contain the 2000P pickup truck impacting head-on into the nose section. However, there

is a potential that there still may be a need for strengthen ing the rail in the longitud inal direction to

prevent complete fracture of the rai l section.

It is ftn1her recommended that a complete set of full-scale crash tests be performed to verify

and complete the compliance testing of the bullnose des ign.

73

10 REFERENCES

I. Ross, H.E., Sicking, D.E., Zimmer, R.A. and Michie, J.D. , Recommended Proceduresjor the Safety Performance Evaluation of Highway Features, National Cooperative Highway Research Program (NCHRP) Report No. 350, Transp01tation Research Board, Washington, D.C., 1993.

2. Button, J.W., Buth, E. and Olson, R.M., Crash Tests of Five Foot Radius Plate Beam Guardrail, Submitted to the Department of Highways, State of Minnesota, Performed by Texas Transportation Institute, Texas A & M University, June 1975.

3. Robertson, R.G. and Ross, H.E. Jr. , Colorado Median Barrier End Treatment Tests, TTl Research Report No. 4179-1 F, Submitted to the Colorado Department of Highways, Performed by Texas Transportation Institute, Texas A&M University, May 1981.

4. Bronstad, M.E., Ray, M.H. , Mayer, J.B. Jr. and Brauer, S.K., Median Barrier Terminals and Median 7/·eatrr.ents. Volume 1 Research Reports and Appendix A, Report No. FHW A/RD-088/004, Final Report to the Federal Highway Administration, Southwest Research Institute, October 1987.

5. Bronstad, M.E., Ray, M.H., Mayer, J.B. Jr. and Brauer, S.K., Median Barrier Terminals and Median Treatments. Volume 2 Appendices Band C, Report No. FHW A/RD-088/005, Final Report to the Federal Highway Administration, Southwest Research Institute, October 1987

6. Bronstad, M. E., Michie, J.D., Recommended Procedures for Vehicle Crash Testing of Highway Appurtenances. National Cooperative Highway Research Program Report 153, 1974.

7. Recommended Procedures for Vehicle Crash Testing of Highway Appurtenances, Transpotiation Research Circular Number 191 , February 1978.

8. Michie, J.D., Recommended Procedures for the Sqfety Pe,formance Evaluation ojHighway Appurtenances, NCHRP Report 230, National Research Council, Washington, D.C., March 1981.

9. Bronstad, M.E., Calcote, L.R., Ray, M.H. , and Mayer, J.B., Guardrail-Bridge Rail Transition Designs- Volume I- Research Report, Report No. FHWA/RD-86/178, Final Repott to the Safety Design Division, Federal Highway Administration, Performed by Southwest Research Institute, April 1988.

74

10. Bronstad, M.E., Ray, M.H., Mayer, J.B., Jr., and McDevitt, C.F., W-Beam Approach Treatment at Bridge Rail Ends Near intersecting Roadways, Transportation Research Record No. 1133, Transportation Research Board, National Research Counci l, Washington, D.C., 1987.

II. Mayer, J.B., Pidi-Sca/e Crash Testing qf Approach Guardrail for Yuma County Public Works Deparfl•zent, Final Report, Project No. 06-211 1, Soutl1west Research Institute, San Antonio Texas, 1989.

12 . Curved W-Beam Guardrail installations at Minor Roadway Intersections, Federal Highway Administration (FHW A), U.S. Depanment ofTransportation, Technical Advisory T 5040.32, April 13, 1992.

13. Ross, H.E., Jr., Bligh, R.P., and Pamell , C. B., Bridge Railing End Treatments at Intersecting Streets and Drives, Report No. FHWA TX-91192-1263-IF, Final Report to the Texas Department of Transportation, Performed by Texas Transportation Institute, Texas A&M University, November 1992.

14. Bligh, R.P., Ross, H. E. , Jr., and Alberson, D.C., Short-Radius Thrie Beam Treatment for intersecting Streets and Drives, Repo11 No. FHWAJTX-95/1442- 1 F, Final Report to the Texas Department of Transportation, Performed by Texas Transportation Institute, Texas A&M University, November 1994.

15. Hinch, J., Yang, T-L, and Owings, R., Guidance Systems for Vehicle Testing, ENSCO, Inc. , Springfield, VA, 1986.

16. Vehicle Damage Scale for Traffic Investigators, Second Addition, Technical Bulletin No. I, Traffic Accident Data (TAD) Project, National Safety Counci l, Chicago, Illinois, 1971 .

17. Collision Deformation Classification- Recommended Practice J224 March 1980, Handbook Volume 4, Society of Automotive Engineers (SAE), Warrendale, Pennsylvania, 1985.

75

76

APPENDIX A

ACCELEROMETER DATA

Figure A-I . Graph of Angular Displacements, Test MBN-1 Figure A-2. Graph of Longitudinal Deceleration, Test MBN- l Figure A-3 Graph of Longitudinal Occupant Impact Velocity, Test MBN- 1 Figure A-4. Graph ofLongitudinal Occupant Displacement, Test MBN- l Figure A-5. Graph of Lateral Deceleration, Test MBN-l Figure A-6. Graph of Lateral Occupant Impact Velocity, Test MBN-l Figure A-7. Graph of Lateral Occupant Displacement, Test MBN-l Figure A-8. Graph of Longitudinal Deceleration, Test MBN-2 Figure A-9. Graph of Longitudinal Occupant Impact Velocity, Test MBN-2 Figure A- l 0. Graph of Longitudinal Occupant Displacement, Test MBN-2 Figure A- l l. Graph of Lateral Deceleration, Test MBN-2 Figure A- 12. Graph of Lateral Occupant Impact Velocity, Test MBN-2 Figure A- 13. Graph of Lateral Occupant Displacement, Test MBN-2

77

Test MBN-1 UNCOUPLED ANGU LAR DISPLACEMENTS

30. 0

20. 0

I

I I

·+

I

.• 10.0

I PITCH

-10. 0 .. ! ..... ·t· I

I ! I !

....................... , ........................... ! ........................... 1 ................................................... ! ...................... ·I·· ....................... ! .......................... : .. l ' I I I i i

I I I I . ' i . .... !...................... . ..................... !'······

ROLL

.......... ~·1·

0. 0 0. 2 0 4 0 . 6 0. 8 1 0 1 2 1 4 1 6

Figure A-1. Graph of Angular Displacements, Test MBN-1

W6: LONGITUDINAL DECELERATION· TEST MBN-1 (EOR-4)

. . . . . . ,. ······-·· -.. •.••••.•••••••.••••••••••••• (. ••••••••••••••••••••••••••• ( •••••.........•••••••••.•••• j ••••••••••••••••••••••••••• ; ••••••••••••••••••••••••••• .;. •••••••••••••••..•...•.•...

I I : : ; I ~ ~ ~

·········-··········· . .......... . .............. . ................. -........................... .

G . . .

•··············· ·· ;···;···. , .

. ' ' r I I r ... ···························~······ ................................................ , ........................... T ........................... r ........................... r .......................... .

0.0 0.1 0.5 0.1

Sec

Figure A·2. Graph of Longitudinal Deceleration, Test MBN- 1

00 0

W7: LONGITUDINAL OCCUPANT IMPACT VELOCITY · TEST MBN-1 (EDR-4)

40 ..... ....................... j···························i····························1···························· ····························l····························t····························

I I I , • . , , T : ,

(/) 20 ····························=-····· ·····················-:-············· ·············~··············· ·············:······· ·····················!····· ................................................. . e: ~ . ~ l ; . . . . . . . . . . . . . . . . ' . . . . . . . . . ' . . . . . . . . . . . ' . . . ' . . . ' . : : : : . . . . . ' . .

tO •••••••· • •••• •••• • •• • ·• ·:-···························-:-···························~········· · ·· ·· ·············· !······· ·····················:····························~ •···························

i : ; i • 1 -·- i ---~- r :

. . . . . . . . . . 0.0 0.1 0.2 0.4 0.5 0.6 0.7

Sec

Figure A-3 Graph of Longitudinal Occupant Impact Velocity, Test MBN-1

W12: LONGITUDINAL OCCUPANT DISPLACEMENT· TEST MBN-1 (EDR-4)

250 ···························-?········ · ··················~····························~··························· . . . . . . . . . . . . . . . . . . .

200 ··············· ············t···························!····························l························· ·· ............. .............. {......... .... ...... ... ... .. . ................... / . . . . . . . . . . . . . . . . . .

·~ .. ...................................................... 1······················T······ ............... . ·············································· .................................. .

. . . . . . . . . . . . . . . 00

. . ::z: 100 ············· ·· ············+···························l····························r··························· ......................... ; ...................................................... .

. . . . . . . . . . . .

. . .............. ··········-:-··························· :···························· ........................... . . . . . . . ~ ······· ··· · · ···· ···········~························ ···:··· ·· ··················· ·· ··' · . . . . . . . . . . . . . . . . . .

0 ~--= ... ~ .... :7:' ... ::: ... ~ ... -r., ........................... ' ....................... ;. ..... ·····················+···························!·········· ·················· ... ... .. .................. . . .

. . . .so ···························~····························: ................. ........... : ............................ :··· ... ......... ...... .

0.0 O.t 0.2 0.3 0.4 •• 0.6

Sec

Figw·e A-4. Graph of Longitudinal Occupant Displacement, Test MBN-1

00 N

W6: LATERAL DECELERATION- TEST MBN-1 (EDR-4)

. . . . ' . ' 10 ····························~···························~····························~····························j····················· ··· ···· .............. ....................................... .

I .

s .... . . . .

~

~ ! 0 IJ .. ... V" .. ~ "rfi"""' .. ~ A j \A A .. ~':,·... ... . ....... V' ..... Y. . . ~ I ~:, ................. .

, ~' ~ ~ "V~ "" . . . . . ················ ............ , ........................... , ...................... \ ··:···························~········ ............. ,··························· ;······ .................... .

. . . . . . 0.1 0.2 0.3 0.4 o.s 0.6 0.7

Sec

Figure A-5. Graph of Lateral Deceleration, Test MBN-1

00 w

W7: LATERAL OCCUPANT IMPACT VELOCITY- TEST MBN-1 (EDR-4)

2 •. ················ ·········~·-········

, .......................... ·······················T·························-r··························

..., 0 .. . . ... ..... .. ... . ..•... ....•.... . .............. . . .... .•.......

~ · ·································· ·l·····················r···················· .......... ·-······ ····················-······· . .

·2 ·························· · · ~· ·· · · · ·· · ·· · ·········· .. ····i· ....................... " 'i ·· ...................... .. ............ ............... ...................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~ .......................... l .......................... 1' .......................... -: ........................... r ..... · ................ ~ .. ......................... j ........ . . .

• • 0 •

•••••••••~•••••••••••••••••••••••••••·~• •••••••••••••••••• 0 ••••"t•·•·••• ••oooo••••••••••••••:-•••••••••••••--•••ooounn~ ooo 4 •... ···············~· ...... .

o.3 05 0.1

Sec

Figure A-6. Graph of Lateral Occupant Impact Velocity, Test MBN-1

00 ....

W8: LATERAL OCCUPANT DISPLACEMENT · TEST MBN-1 (EOR-4)

2 ····· ·-···················~····························; ........................... ~ .......................... . . .

. !

' ·······-···················f·········· ........... . . . . . ··t···························r·····-····················· : :

............ T .......................... 1 ...... .

. . . .

% : ~ 1 r + -~ J: : ---: : : : : : j ~ ~ l 1 l ~ : ~ ~ ; 1 . . . . : : : : . . . .

•2 ·••••••·•••••·•• .. ·········t ·····.......................................... ·· r··············· .. ··········t·················· .. ·······r·· ···················· .. ·+··· ........................ . : : : : : 1 ~ ~ l l ~ 1 1 1 ; 'I ........... r............................................. ......... -- .... ... .. .

~ ~ . 1 ~

-3 •••••••

0.1 ... 0.& 0.7

Sec

Figure A-7. Graph of Lateral Occupant Displacement, Test MBN-1

00 V>

W6: LONGITUDINAL DECELERATION· TEST MBN-2 (EDR-4)

. . . . . 15 ....... ···················~ · ········· · ················ ~····························{······················ ······ ...............................•... . . ... ........ ........... . .. ...... . .. . .... . ......

, : I

. . 10 ......................... ······················r···························r························· ................................................................................ .

s ........................ '('""" ... " """""'t""""' .... """" 't""""""""""""" ................................................. .. . . . . . . . . . .

0 """ """"""""" . . . . . .

··:-········ ········ ··········· ~ ···························~·············· . ···········:····························:····························i··· l ; j j ~ l

. I I ~ I : -5 .......... .. .. ··· t ····· ·············· ········ ·i·· ··························i····························i···························· j········ .......... '

0.0 0.1 0.2 0.4 o.s 0.7

Sec

Figure A-8. G1aph of Longitudinal Deceleration, Test MBN-2

00 0.

W7: LONGITUDINAL OCCUPANT IMPACT VELOCITY- TEST MBN-2 (EDR-4)

tOO ··········· ··············· ·r···· ·······················1····························l··························· r ······· ·········· · ·· · ······~ · ························· ···························· . . . . . . . . . . . . . . . ' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

00 ............ ..... .. ; : : . . . ' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' . . .

60 ···························1········ ... ·················1························· .. -~ ............ ···············'(····························:··. ·······················t····· .. ······ .. ····· .. ······ . . . . . . . .

. . . .......................................................................................................................................... . . . . . . <n . . e: 40 ........................... .;. ••••••••••••••••••••••••••• :.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

20 .... ............. . ······-···························l····························j···························-······ ..................... , ....... ···················r··························

. . . . . . . . . . . 0 ................ ......... ; . . ··· · ···· ···· · · ·· · ··· ·····j····························t···················· ···· ···t·· ········ · ······· ·········~····························; .......... ................ .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ·20 ............•••••••••••••.••................ . . .

······················ ·····~······ ·· ····· ·············· ~······ ·······

0.1 0.2 0.4 0.6

Sec

Figure A-9. Graph of Longitudinal Occupant Impact Velocity, Test MBN-2

00 .....,

W12: LONGITUDINAL OCCUPANT DISPLACEMENT- TEST MBN-2 (EDR-4)

$00 ........................... { •••••••••••••••••••••••••••• j ..••.••.•..•..•..........••• ~ ••..••••.•••••••••••••••••• { •••••••••••••••••••••••••••••••••••••••••••••••••••••... ; ••••• _,,, •••••••••••••••••

~ ~ .

... ...... ............... r·· ........................ ! ............................ , ........................... ; ............................ ' ....................... ····~ ......................... . : ~ i :

····l··························J····························r··························-.. ················································

. . . . . . . . . . . ' .

100

.~ l----""'.•-::•:::•::••:::••:"1r r r · r _ _ r : ~· 03 0.& 0.7

Sec

Figure A- 10. Graph of Longitudinal Occupant Displacement, Test MBN-2

00 00

W6: LATERAL DECELERATION· TEST MBN-2 (EOR-4)

10 ·····t······ . . ............................................. . ··························· ........................... , ............................. .

•• o ... ····················t ..... ············i········· .... ··············<····························l···························l······················· ''''[''''''''''''''''''''''''''''

: : : : : : : . . . . . . . . . . .

0.0

Sec

Figure A-ll. Graph of Lateral Deceleration, Test MBN-2

W7: LATERAL OCCUPANT IMPACT VELOCITY · TEST MBN-2 (EDR-4)

' ' . . ..0 ,,,,.,, ... uunn•••••••·-•••••••••••••••••••••••••••7•••••••••••••••••••••••••••~~••••••••••••••••••••••••••• 000000000000000000000000000 ••••••••••••••••••••••••••• ••••·•••••••••••••••••••••••

. . )0 ••••••• • ·············-·· •••••••

. . . . . - - ---·-················································································ . . . . . . . . . . . . . . . . . . . . .

............... ~ ........................... ~ ............. . . . . . 20 ........................................... ' . ' . . . . .

' . .. .... ................... ........... ..................................................................................... . ' . ' . ' . ' . ' . ' ' . .

·o ····························r······················· .... t ....... ' ' . ' ' ' . ' ' . . ' ' ' ' . . ' . . . . . . . . . . . . . . . .

o ~"'"'""""""' ........... ·r .... .. : 1 r r

1

- ---

0.0 0.1 0.1 0.7

Sec

Figure A-12. Graph of Lateral Occupant Impact Velocity, Test MBN-2

WB: LATERAL OCCUPANT DISPLACEMENT· TEST MBN-2 (EDR-4)

110 ••••••••••••••• ••• 00 ••••

i 100 ••.••. 00 .............................................. ; •••••••••••••••••••••••••••• ; •••••••••••••••••••

. . .. ····-:-........................... ~ ·························· ...... ····················· . . . . . . . . . . . . . . . . . . . . . . . . . .

0 ' • • •••••••• •• ••••••••••••••• , ••••• •••••••••••••••••••••!•••••••••••••••••••••••••••~••·••• • •••·•• • •• ••I m ••••• ••• j •••••• •••••••••••••••••••••

. . . . . . . . 0.0 .. , .. , .. ,

Sec

Figure A-13. Graph of Lateral Occupant Displacement, Test MBN-2

APPENDIX B

STRAIN GAUGE DATA

Figure B-1. Strain Gauge No.3 Data, Test MBN-1 Figure B-2. Strain Gauge No.4 Data, Test MBN-1

91

W7: Thrie Beam -Strain Gauge No. 3 · Midspan Between Post Nos. 4 and 6 - Back-Side Neutral Axis

10 .. . ............... . : ........ ~ ........................................................................................... ; .................... .

5 t···················: .. ··· ··· ·········· . /"1' 1"'£--~.JV~..rv--""""'v"\ "'""M · --J'-./V\"1\fV\rvv.. ·vI "'VI

... ...... .. ... , ................... :······''-'·".1····'··•···················•·················· <····················!

0 j N ~~~ 11

·r·tv·······ilt·················Ui·····I·Jt'l 1, J

: : 4 1················ ··· ' ······ ··············•······ ·········· ·· .. ; .................... ,, ..................... , ......... ........... , .................... , ....................• , ................. . ~

0.0 0.2 0.4 M u 1.0 1.2 1.4 ' 1.6 1.8 10

Sec

Figure B-1. Strain Gauge No. 3 Data, Test MBN- 1

W7: Thrie Beam -Strain Gauge No. 4- Midspan Between Post Nos. 4 and 6- Back ..Side Neutral Axis

. . s ................... ; ................... :

I . . . : . : .

·················r··················r··················1···················~··············· ····; .. ·················r················· r······· ············ : : : : : : : : : : : : i j j ~ .

•••• • ••••i•••••••••••••••••••~• •••••• ••••••••ooua.:o••uuoo• oooo oooO•o•ooooooooooooooo ~0000000 0000 ••••••• . .

j • . - r··-~·-·············· ··;·················-; ··················-············· ]··········· ~--··· r··············· ~--·-··-·····

.. ·················· ~--·················1················ ................ --~· - ·············· ·················~···················,··················I···· ............. -~·-· ............... .

.• s .................. ~ ................... : ................... :-................. T ................. T .................. ·r ................... ! ................... r ..................................... .

0.2

Figure B-2. Strain Gauge No.4 Data, Test MBN-1

1.0

Sec 1.2 u ...