Kenneth Weddfelt

Applied Mechanics Group, Special Engineering Services

Rocktec

Atlas Copco Rock Drills AB

2

Atlas Copco Group

3

The Atlas Copco Organization

Executive Group Management and Corporate Functions

Oil-free Air

Industrial Air

Portable Air

Specialty Rental

Gas and Process

Airtec

CompressorTechnique

Construction and Mining Technique

IndustrialTechnique

Underground RockExcavation

Surface DrillingEquipment

Drilling Solutions

Secoroc

Construction Tools

Road Construction Equipment

Geotechnical Drillingand Exploration

Rocktec

Atlas Copco Tools and Assembly SystemsMotor Vehicle Industry

Atlas Copco Toolsand Assembly Systems General Industry

Chicago PneumaticIndustrial

Chicago PneumaticVehicle Service

Tooltec

Customer Centers and Service Providers

President and CEO

Board of Directors

4

Worldwide Presence

Production sites

5

Strong Brands

6

Atlas Copco in Örebro

7

Örebro557

Total world wide 3300

Atlas Copco Rock Drills AB

Employees in Örebro and rest of the world

UndergroundRock

Excavation

Surface DrillingEquipment

RocktecDistribution

CenterCMT Shared

Service

Örebro221

Total world wide 1600

Örebro187

Örebro98

Örebro47

”Atlas Copco, the biggest private employer in the Örebro province”

1110 employees in Örebro

December 2009

Atlas Copco The Örebro organisation

8

Rocktec Innovative Solutions

Products Services

Knowledge

9

Vision

To be First in Mind—First in Choice ® for Rock Drills, Automation Solutions

and Specialist Engineering Services.

Specialist Engineering Services

11

Industrial Design Patents

Ensure the appearance of our products carries the Atlas Copco values and emphasizes their unique features

Responsible for the patent and design rights activities within CMT global and support CMT in Sweden

Specialist Engineering Services

12

Measurement Technique Materials & Rock Drills Lab

Dedicated measurements, systems and noise & vibration design on CMT products through the whole development process

Technical knowledge, investigations and laboratory tests within materials engineering and percussion systems

Specialist Engineering Services

13

Applied Mechanics CAD Support

Develop technically correct products using numerical & analytical calculation methods and laboratory tests

Serve & support internal and external clients using CAD and Product Data Systems within Atlas Copco Rock Drills AB

Specialist Engineering Services

14

Applied Mechanics - Specialist Engineering Services

Eva Hyvärinen

In-house specialist service in applied

mechanics providing reliable solutions to

technical problems

Focus on expertise in CMT products and

needs

Act within CMT, assist with investigations,

technical calculations and laboratory tests

utilizing state-of-the-art knowledge and tools

Introduce new methodologies for design and

technical analysis and interact with external

centers of competence

Mahesh Grampurohit

ECC / Bangalore

15

Rocktec

Global R&D Center

Drilling

Solutions

Geotechnical Drilling

and Exploration

Secoroc

Rock Drilling Tools

Surface

Drilling Equipment

Underground

Rock Excavation

– Tunneling and Mining Equipment

– Trucks and Loaders

Applied Mechanics - Our Clients: The Business Area CMT

16

Strategies

– Rock Fracture Mechanics

PhD project with target to increase our knowledge and methodology to

study fracture phenomena in rocks relevant to CMT drilling applications

– Thread Connection Analysis

Increase competence on CAE driven design of functional, fatigue and

wear aspects of special thread connections used for CMT drilling

applications

– Development of Procedures for Vibration Analysis

Adapting state of the art procedures for analysis of vibration problems to

our products

– Structural Strength Design of Welds Using Modern FE-

based Methods

Develop efficient and accurate methods for weld analysis and design,

utilizing results from full vehicle FE models

– Fast Turnaround of Early Design Analysis Work

Develop efficient methodology to enable fast component analysis while

still retaining the macroscopic behavior of vehicles

17

Committed to

sustainable productivity.

18

19

Percussion Rock Drill – Core product of RTE

100Hz

10.000h

109 - 1010 load cycles

Nominal axial stress level

300 MPa amplitude

20

Percussion Piston – Clean High Strength Steels

MPaSu 450%50,

mRa 1

MPaRM 1150

MPaSu 350%1.0,

MPaSy 31040270,350

21

Percussion Piston – Murakami inclusion theory

MPaR

Area

HVHV

w 2902

28.11

000.20

12029056.1

2

112056.1

029.0226.0

61

10226.0

61

4

MPaS y 28535250,320

Thread Joint Design - Core Product of CMT

Behaviour modelling of a complex structural joint

where small details can be important for its load carrying capacity

23

Thread Joint Analysis - Characteristics of

Two stage analysis

– Pre stress state, e.g. tightening

– External load on joint

Indeterminate problem

– Even the ideal case has at least two load

transmission paths

– A real case often have several different

load transmission paths

Highly non linear problem

– Many contact surfaces where stiffness

varies

– Small design changes can have large

influence on stress state

Friction dependant

24

Nominal Method / Detailed Analysis

Nominal method

– Loads from structural analysis

Hand calculation

Measurement

FE analysis

– Nominal stress

– Allowed stress from design rules for

specific joint type used

BSK99 2.3% risk: 25MPa amp

8.8 bolt: 50MPa amp

12.9 bolt: 35MPa amp

Rolled tread: 80MPa amp

………

Detailed analysis

– Loads from structural analysis

Fem analysis

Measurement

– Local linear elastic/plastic stress

– Allowed stress from design rules for

specific material used

Mean stress reduction

Surface finish reduction

Failure risk reduction

Residual stress influence

– A geometry model must be

assumed for a FE analysis

Should it be made with nominal

measures or include tolerances?

b

b

W

M

A

F

25

FE based Fatigue Analysis of Threads

– Failure usually occur at first load carrying

– Notch theory

– Kt appr. 5,6,7… (elast)

– Kt appr. 2 (plast)

– Analysis based on nom-inal stress and strain

– Stress – life Ok

– Su appr. 50MPa amp

– Analysis with local stress an strain

– Strain – life

– Plasticity

– Coffin - Manson

26

Material model

– Kinematic plasticity law similar to VOCE; using MKIN,PLASTICITY

27

Thread with Fatigue Load Applied

MPa1300 %55.0

Stress width larger than ultimate stress

28

Strain – Life: Coffin – Manson law

c

ff

b

f

f

tot NNE

22 '

'

c

ff

b

f

f

tot NNE

22 '

'

0.7-0.5,-exponentductilityfatigue

0.12-0.05,-exponentstrengthfatigue

tcoefficienductilityfatigue

tcoefficienstrengthfatigue

amplitudestrainmechanicaltotal

'

'

c

b

f

f

tot

29

Comparison with tests

67.0-

081.0-

05.1

3501

0001

'

'

c

b

MPa

MPaR

f

f

m

c

ff

b

f

f

tot NNE

22 '

'

Parameter values are from typical hand book data, i.e. non specific for this material

0

50

100

150

200

250

300

350

1000 10000 100000 1000000 10000000 100000000

Lastcykler

No

min

ell s

kru

vsp

än

nin

g [

MP

a]

M16 8.8

M16 12.9

M22 8.8 Ansys

30

A Paradigm for Conceptual Assessment of

Design Changes Influence on Life Length

Helpful for fast, non detailed, conceptual design studies, reusing available load

and component strength data

Recognizes three different design phases

– Load characterization, e.g. measurements

Define wear rates

– Component characterization, e.g. FE analysis results

Define Load case and component stress response

Define component capacity

– Configuration of different design setups

Different usage descriptions

Different feed assemblies, weight and inertia

Etc

Does not explicitly mention load cycles! The concept of load cycles has proven to be

very confusing to our customers)()( force

b

bstressLife

f

M

Mf

Wroc

CocT

31

Load Description

Description Sequences Wroc 7s

Drilling 1,13,14,15,16,17 0.0019

Positioning 2,18,19 0.1997

Low speed tramming, hard on support 3,7,20,21 0.0058

High speed tramming, hard on support 11,22 0.0008

Low speed tramming, loose on support 4,23,24,25 1.5029

High speed tramming, loose on support 26,27 0.5007

Low speed tramming, boom 45 degree, fully 5,28 0.6180

Low speed tramming, boom 45 degree, folded up 10,29,30 0.7525

Low speed tramming, boom folded up 6,8,31,32,33 1.2407

High speed tramming, boom folded up 12,34 0.8364

Provocation of the boom using hydraulic pistons 9 11.7326

measured

i

ii

T

n

WrocA list of values for Wear Rate of Capacity

Data from ÖDS measurement 2008

32

Component Description

Analysis assumptions

Steel GS 24Mn6 V3

Design load: Bending moment 160kNm width

at pin

Analysis results

(Maximum stress width 210MPa)

Stress dependence of load

Capacity of Component at desired failure risk

(Basquin Law)

bbstress MMf 1312)(

303

%1.0 101.11NCoc

33

Configuration Description

222 80047096.2583.0598951700 kgmJ joint

What is the life length with the standard usage description?50% drilling, 35% positioning, 10% tram drill pos, 5% tram in support

Feed weight m=5989kg, Jcog=51700kgm2

Evaluated in standard drilling position

7175.02

0008.00058.005.0

2

8362.02407.11.01997.035.00019.05.0 sWroc

80047)(forceb fM

)()( force

b

bstressLife

f

M

Mf

Wroc

CocT

hsTLife 15211107.54800471312175.0

101.11 6330

bbstress MMf 1312)(

34

Configuration Description

222 80047096.2583.0598951700 kgmJ joint

What is the life length if tramming increases?40% drilling, 30% positioning, 25% tram drill pos, 5% tram in support

Feed weight m=5989kg, Jcog=51700kgm2

Evaluated in standard drilling position

7320.02

0008.00058.005.0

2

8362.02407.125.01997.030.00019.040.0 sWroc

80047)(forceb fM

)()( force

b

bstressLife

f

M

Mf

Wroc

CocT

hsTLife 8318109.29800471312320.0

101.11 6330

bbstress MMf 1312)(

35

Configuration Description

222 929158583.020080047 kgmJ joint

What is the life length if adding a winch of 200kg 8m up on feed?40% drilling, 30% positioning, 25% tram drill pos, 5% tram in support

Feed weight m=5989kg, Jcog=51700kgm2 plus additional component

Evaluated in standard drilling position

92915)(forceb fM

)()( force

b

bstressLife

f

M

Mf

Wroc

CocT

hsTLife 9726100.35929151312175.0

101.11 6330

7175.02

0008.00058.005.0

2

8362.02407.11.01997.035.00019.05.0 sWroc

bbstress MMf 1312)(

36

Configuration Description

222 80047096.2583.0598951700 kgmJ joint

What is the life length for provocation only?Feed weight m=5989kg, Jcog=51700kgm2

Evaluated in standard drilling position

7.11Wroc

80047)(forceb fM

)()( force

b

bstressLife

f

M

Mf

Wroc

CocT

hsTLife 2271082.08004713127.11

101.11 6330

bbstress MMf 1312)(

37

Nominal Stress – from FE stress results

Nominal Stress

– Linear elastic stress in a sectional area

including macrogeometric features and

concentrated loads

– Local in-plate shell bending

Simple Geometries

– Elastic beam theory

– Handbook formulas

FE model results

– Complex and over determined structures

– Coarse mesh sufficient

– Weld details not modeled

– FE model cleaned from misalignments

unless larger than covered for by joint class

38

Modified Nominal Stress – from FE stress results

1.12.158

50

97

60

77

402222

//

//

2

//

//

2

rvdrdrd fff

39

Weld stress - From FE Section Force/Moment results

22

6

22

0

0

a

MF

a

t

z

x

20

at

M y

220

a

Fz

at

M x

//

a

Fy

2//

2

//

//

22

//

//

2

rvdrvdrdrd ffff

40

Committed to

sustainable productivity.