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VEHICLE TECHNOLOGY DIRECTORATE
Crash Simulation of a Vertical Drop Test of a B737 Fuselage Section with Overhead Bins
Karen E. Jackson and Edwin L. FasanellaUS Army Research Laboratory
Vehicle Technology DirectorateNASA Langley Research Center
Hampton, VA 23681
Third Triennial Aircraft Fire and Cabin Safety ConferenceAtlantic City, New Jersey
October 22-25, 2001
• In November of 2000, the FAA performed a 30-ft/s vertical drop test of a 10-ft. long fuselage section of a Boeing 737 (B737) transport aircraft
• The fuselage section was outfitted with two different commercial overhead stowage bins and luggage
• The objective of the test was to evaluate the dynamicThe objective of the test was to evaluate the dynamic response of the overhead bins in a narrow-body response of the overhead bins in a narrow-body transport fuselage section subjected to a severe, but transport fuselage section subjected to a severe, but survivable, impact eventsurvivable, impact event
• This test also provided a unique opportunity to evaluateThis test also provided a unique opportunity to evaluate the capabilities of computational tools for crash the capabilities of computational tools for crash simulation simulation
Introduction and Background InformationVEHICLE TECHNOLOGY DIRECTORATE
• To develop a finite element model of the fuselage section suitable for execution in a crash simulation
• Perform a crash simulation using the nonlinear, explicit transient dynamic code, MSC.Dytran, and generate pre-test predictions of fuselage and overhead bin dynamic responses
• Validate the model through extensive analytical and experimental correlation
• Assess simulation accuracy and suggest changes to the model for improved correlation
ObjectivesVEHICLE TECHNOLOGY DIRECTORATE
VEHICLE TECHNOLOGY DIRECTORATE
Vertical Drop Test of a B737 Fuselage Section
Pre-test photographPre-test photograph
• 10-ft. long section of a B737-100 transport aircraft from FS 380 to FS 500, weighing 1, 360-lbs.
• Six triple-occupant passenger seats with test dummies and mannequins
• 3,229-lbs. of luggage
• Two different commercial overhead stowage bins loaded with wood
• 14-ft. drop test onto wooden platform for 30-ft/s vertical velocity
• ≈140 channels of data collected at 10,000 samples per second
VEHICLE TECHNOLOGY DIRECTORATE
Vertical Drop Test of a B737 Fuselage Section
Heath Tecna Overhead Bin
Forward
FS 400 FS 420 FS 440 FS 460 FS 480
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Vertical Drop Test of a B737 Fuselage Section
Hitco Overhead Bin
Forward
FS 440FS 460FS 480 FS 420 FS 400
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Asymmetry in the Test Article
Seat rails
Seats
Rear
Front
RightLeft
Floor Plan View Schematic Photograph of the Cargo Door
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Vertical Drop Test of a B737 Fuselage Section
Post-test Photographs
Right-sideRight-sideseat failureseat failure
Asymmetric deformationof the lower fuselage
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MSC.Dytran Model Development
Crash Simulation of the Vertical DropTestof the B737 Fuselage Section
• Model geometry was developed from hand measurements, i.e. no engineering drawings available
• Model contains 9, 759 nodes and 13,638 elements, including 9, 322 shell and 4, 316 beam elements
• Seats, dummies, cameras, luggage, and plywood in bins modeled using concentrated masses
• Material properties were estimated using engineering judgementFront view of model
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MSC.Dytran Model of the Heath Tecna Bin
Crash Simulation of the Vertical DropTestof the B737 Fuselage Section
Three-quarter view
Side view
Front view
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MSC.Dytran Model of the Hitco Bin
Crash Simulation of the Vertical DropTestof the B737 Fuselage Section
Side view
Front viewThree-quarter view
VEHICLE TECHNOLOGY DIRECTORATE
Crash Simulation of the Vertical DropTestof the B737 Fuselage Section
• Rigid impact surface was added to represent the wooden platform
• 3 master-surface to slave-node contact surfaces were defined between: - the impact surface and lower fuselage structure - the Heath Tecna bin and the upper fuselage structure - the Hitco bin and the upper fuselage structure
• The model was executed for 0.2 seconds of simulation time, requiring 36 hours of CPU on a Sun Ultra Enterprise 450 workstation computer
MSC.Dytran Model Execution
Three-quarter viewof model
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Analytical and Experimental Correlation
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Exp. (ch 218)Dytran (node 3974)
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Exp. (ch 219)Dytran (node 3758)
Acceleration, gAcceleration, g
Time, s Time, sLeft outer seat track Left inner seat track
Vertical Acceleration Responses of the Left-Side Inner and Outer Seat Track at FS 484
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Analytical and Experimental Correlation
Vertical Acceleration Responses of the Right-Side Inner and Outer Seat Track at FS 484
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Exp. (ch 223)Dytran (node 8486)
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Exp. (ch 222)Dytran (node 8270)
Acceleration, g Acceleration, g
Time, sTime, s
Right outer seat track Right inner seat track
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Analytical and Experimental Correlation
Vertical Velocity Responses of the Left- and Right-Side Outer Seat Track at FS 418
Left outer seat track Right outer seat track
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Left outer seat trackMSC.Dytran
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Right outer seat trackMSC.Dytran
Velocity, ft/s
Time, s
Velocity, ft/s
Time, s
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Analytical and Experimental Correlation
Vertical Acceleration Responses of the Left- and Right-Side Lower Side Wall at FS 480
Left-side lower side wall Right-side lower side wall
Acceleration, g
Time, s
Acceleration, g
Time, s
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ExperimentAnalysis
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ExperimentAnalysis
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Axial Force Responses of the Vertical SupportRods HT-1 and HT-3 of the Heath Tecna Bin
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-0.05 0 0.05 0.1 0.15 0.2 0.25 0.3-1000
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Axial Force, lbs.
Time, s
Axial Force, lbs.
Time, s
Forward support rod, HT-1 Rear support rod, HT-3
Measured tensile failure load = 1,656 lbs.
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Axial Force Responses of the .616-in. DiameterSupport Rods H-1 and H- of the Hitco Bin
Axial Force, lbs.
Time, s
Axial Force, lbs.
Time, s
Support rod, H-1 Support rod, H-2
Measured tensile failure load = 5,350 lbs.
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ExperimentAnalysis
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ExperimentAnalysis
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Analytical and Experimental Correlation
Predicted Structural Deformation
Time = 0.0 s Time = 0.06 s Time = 0.09 s
Time = 0.12 s Time = 0.15 s Time = 0.18 s
Concluding Remarks
• A finite element model of the B737 fuselage section with overhead bins and luggage was developed and pre-test predictions of fuselage and bin responses were generated
• The model was generated from hand measurements of fuselage geometry (no engineering drawings were available)
• Predicted floor-level acceleration responses compared favorably with experimental data with peak acceleration values with ±5-g
• Integrated velocity comparisons indicate that the model is too stiff and removes velocity more quickly that the test
• Deformed plots of the model indicate excessive deformation of the lower fuselage structure into the cargo hold
VEHICLE TECHNOLOGY DIRECTORATE
Ongoing ResearchVEHICLE TECHNOLOGY DIRECTORATE
• Incorporate platform model
• Model luggage physically using solid elements
• Add rotation springs at joints between bin linkages
• Modify material properties
• Rediscretize model in certain regions
• Examine the effect of the contact penalty factor
Suggested Model Improvements
Fuselage Model with Platform
Fuselage Model with Luggage
AcknowledgementsVEHICLE TECHNOLOGY DIRECTORATE
• This research was performed under an Inter Agency Agreement DTFA03-98-X-90031, established in 1998, between the US Army Research Laboratory, Vehicle Technology Directorate and the FAA William J. Hughes Technical Center.
• The technical support and contributions provided by Gary Frings, Tong Vu, and Allan Abramowitz of the FAA are gratefully acknowledged.