Presentation by

Mr. Sumedh Kousadikar

Mr. Santosh Kumar

Mr. Atul Patil

January 22 , 2013 Pune, India

Bending fatigue life evaluation of

Crankshaft with induction hardening effect

via FEMFAT boundary layers

R&D CDFD Engineering

Bharat Forge Ltd. Pune, India

FEMFAT USER CONFERENCE 2013

Presentation Sequence

• Introduction

• Kalyani Group & Bharat Forge Overview

• Objective & Methodology

• Approach 1: Introducing hardness effect via Boundary layer

• Approach 2: Hardness effect via Boundary layer & Forge factor

• Correlation between FEMFAT & physical test results

• Conclusion & Future Work

R & D CDFD ENGG CMMI (ML-3)

• Bharat Forge Overview

2 FEMFAT USER CONFERENCE 2013

Global Footprint

BFL

Capacity over 760,000 Tons per annum

Crankshaft machining capacity of 1,200,000 Nos.

Capacity to machine 500,000 FAB & 750,000 steering knuckles

Skilled workforce of 7000 Worldwide.

CAPACITY

60,000 tons

CAPACITY

200,000 Tons

CAPACITY

365,000 Tons

CAPACITY

135,000 Tons

2

3

1

5

6 4

2

3

4

5

6

CDP BHARAT FORGE

Ennepetal, Germany

BHARAT FORGE DAUN

Daun, Germany

BF ALUMINIUMTECHNIK

Dresden, Germany

BF AMERICA

Lansing

BHARAT FORGE KILSTA,

Sweden

FAW BF (Changchun) Co. Ltd.

Changchun, China

• Strong Foray in the largest

auto market USA

• Strong customer

relationship

• Dual Shore manufacturing

• Manpower: 83 People

• Production base close to the

customer

• Proximity to large marquee

Customers

• Dual Shore manufacturing

• Manpower: 1060 People

• JV with FAW in China with

52% stake

• Foothold into fastest

growing market

• Dual Shore Manufacturing

• Manpower: 1500 People

• Worlds largest single

location forging facility

• Technologically advanced,

flexible forging & machining

facility

• Proximity to fast growing

Auto markets of China &

India

• Dual Shore manufacturing

• Manpower: 4700 People

1

FEMFAT USER CONFERENCE 2013 R & D CDFD ENGG CMMI (ML-3) 3

GLOBAL PRESENCE - Automotive

GLOBAL & DOMESTIC CLIENTS

R & D CDFD ENGG CMMI (ML-3) 4 FEMFAT USER CONFERENCE 2013

Global & Domestic – Non Automotive

R & D CDFD ENGG CMMI (ML-3) 5 FEMFAT USER CONFERENCE 2013

New Verticals… Greater Focus… India’s Growth

Non - Auto Business

Energy Transportation Construction & Mining

Railways

Aerospace Oil & Gas

Supporting global core infrastructure sectors

Marine

Construction

Wind Thermal Hydro Nuclear

Power

Metal & Mining

General

Engineering

FEMFAT USER CONFERENCE 2013 R & D CDFD ENGG CMMI (ML-3) 6

Crankshaft manufacturing process involves forging, heat treatment, machining, grinding,

shot blasting & induction hardening.

Forging Machining Induction hardening Fatigue testing

& Validation

Fatigue testing of crankshaft is a complex engineering process, which requires lot of

theoretical calculations, practical work, time & cost.

Crankshaft fatigue life can be improved by optimizing design & process parameters. But

it’s physical test validation needs lot of testing time & other expenses. So to reduce these

complexities, it is important to virtually simulate the crankshaft fatigue testing process &

predict the fatigue life.

Introduction

R & D CDFD ENGG CMMI (ML-3) FEMFAT USER CONFERENCE 2013 7

Bending fatigue life evaluation of crankshaft with induction hardening effect via FEMFAT

boundary layers.

Crankshaft bending fatigue life correlation between FEMFAT & physical test results.

Methodology:

Import ANSYS stress

results into FEMFAT &

apply different IH

process parameter effect

via boundary layers

Conduct FE analysis Predict fatigue life

& validate results

Objective & Methodology

R & D CDFD ENGG CMMI (ML-3) 8 FEMFAT USER CONFERENCE 2013

Following input parameters are taken for bending fatigue life evaluation of five different

capacity crankshafts.

The load spectra applied is actual (B50) mean fatigue strength of crankshaft.

All analysis are performed on load ratio (R=-1) fully reverse condition.

Other parameters like technological size influence, forge factor, are activated based on pin

diameter of crankshaft.

Crankshafts Input data for FEMFAT Analysis

S.N. Crankshaft Material Pin Dia(Ø) mm UTS (MPa) YS (Mpa) Surface Hardness

(HRc) Surface finish

(Ra) µ

1 A Micro alloyed 70 780-930 450 52 0.25

2 B Micro alloyed 90 750-900 450 53 0.25

3 C Q & T 94 930-1080 760 50 0.25

4 D Micro alloyed 95 850-1000 550 55 0.25

5 E Micro alloyed 100 850-1000 550 56 0.25

Input data for analysis

R & D CDFD ENGG CMMI (ML-3) 9 FEMFAT USER CONFERENCE 2013

Following parameters are considered for analysis, Material: Micro alloyed steel. Applied stress level 875 MPa UTS 850 MPa Pin Diameter: 94 mm Technological size influence ON Forge Factor ON Surface Roughness 0.2 µ Stress ratio R=-1 B50 fatigue life

FEMFAT fatigue

life Expected

fatigue life % of variation

5.82E+03 10E+06 99.94%

Fatigue life Requirement:

10Million no. of cycles for 875 MPa

Without Induction hardening effect

Fatigue life analysis using FEMFAT

R & D CDFD ENGG CMMI (ML-3) FEMFAT USER CONFERENCE 2013 10

Similarly fatigue life evaluated for other sizes of crankshafts as shown below.

BENDING FATIGUE TEST CORRELATION

Sr No. Crankshaft B50 physical

test (MPa) Pin Diameter

(mm) Number of cycles

Calculated cycles by FEMFAT

% Difference

1 A 875 70 10E+06 2.38E+04 99.76%

2 B 757 90 10E+06 2.69E+05 97.31%

3 C 880 94 10E+06 5.56E+04 99.44%

4 D 875 95 10E+06 4.47E+04 99.55%

5 E 875 100 10E+06 2.99E+04 99.70%

Without hardening Influence, the fatigue life achieved is very small as compared to

expected no. of cycles (10 Millions)

Fatigue life analysis using FEMFAT

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Hardness 55 HRC

Fatigue life Requirement:

10Million no. of cycles for 875 MPa Achieved fatigue life: 9.1 Million cycles

Result correlates well

Approach 1: Introducing hardness effect via Boundary layer

One of the crankshaft is simulated for fatigue life evaluation using FEMFAT with introducing

hardness effect in terms of UTS at 3mm boundary layer.

R & D CDFD ENGG CMMI (ML-3) FEMFAT USER CONFERENCE 2013 12

Following parameters are considered for analysis Material: Micro alloyed steel. Pin Diameter: 94 mm Technological size influence ON Forge Factor ON (default taken as 1) Surface Roughness 0.2 µ Stress ratio R=-1 B50 fatigue life Mechanical properties (YS, UTS 850 MPa) Applied stress level 875 MPa

Following parameters are considered for analysis Material: Micro alloyed steel. Pin Diameter: 94 mm Technological size influence ON Forge Factor ON introduced as 1.9 Surface Roughness 0.2 µ Stress ratio R=-1 B50 fatigue life Mechanical properties (YS, UTS 850 MPa) Applied stress level 875 MPa IH Boundary layer ON

Approach 2: Introducing hardness effect via Boundary layer & Forge factor

R & D CDFD ENGG CMMI (ML-3) 13 FEMFAT USER CONFERENCE 2013

Forge factor in the FEMFAT depends on geometrical complexities of forging components. we

have related forge factor with pin diameter of crankshaft.

For most of the crankshafts trend observed, as pin diameter increases forge factor decreases.

For few exceptional cases, e.g. if pin diameter is more with less counterweight masses

forge factor varies proportionally with geometry of crankshaft.

y = -0.0015x2 + 0.2175x - 5.5546

0.5

1

1.5

2

2.5

3

60 70 80 90 100 110

Fo

rge

Facto

r

Pin diameter

Pin diameter Vs. Forge factor

Crankshaft

Dia 70

Dia 90

Significance of forge factor during fatigue life evaluation

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BENDING FATIGUE TEST CORRELATION

Sr No. Crankshaft B50 physical

test (MPa) Pin Diameter Forge factor Number of cycles

Calculated cycles by FEMFAT with Forge

factor

% Difference With forge factor

1 A 875 70 2.45 10E+06 1.02E+07 -2.0%

2 B 757 90 2.06 10E+06 9.77E+06 2.3%

3 C 880 94 1.92 10E+06 9.92E+06 0.8%

4 D 875 95 1.78 10E+06 1.02E+07 -2.0%

5 E 875 100 1.45 10E+06 9.95E+06 0.5%

Following crankshafts are simulated for fatigue life evaluation using FEMFAT,

with combination of boundary layer & forge factor effect.

Results shows good correlation between FEMFAT & physical test

Comparisons of fatigue life evaluated by FEMFAT and physical test

R & D CDFD ENGG CMMI (ML-3) FEMFAT USER CONFERENCE 2013 15

Crankshafts are simulated for fatigue life evaluation using FEMFAT by introducing

processing parameter effect, boundary layer with different hardness ranges & forge factor.

This study shows good correlation with physical test.

This study will be beneficial for virtual estimation of crankshaft fatigue life. This will help

to reduce product development time, cost & efforts.

Correlation for fatigue life between physical test and virtual test will be useful for

crankshaft design & manufacturing process optimization.

Future Work:

To study the effect of different process parameters (hardness, surface finish, case

depth, residual stresses) on fatigue life of crankshaft using FEMFAT and its

experimental validation.

Conclusion & Future Work

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www.bharatforge.com

Thank You

Any Questions?

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