Investigation of residual stresses generation in aluminum flywheel

INVESTIGATION OF RESIDUAL

STRESSES GENERATION IN ALUMINUM

FLYWHEEL

Afsaridis Kimon

THESIS WORK 2009

PRODUCT DEVELOPMENT AND MATERIALS

ENGINEERING

INVESTIGATION OF RESIDUAL

STRESSES GENERATION IN ALUMINUM

FLYWHEEL

Afsaridis Kimon

This thesis work is performed at Jönköping Institute of Technology within the

subject area Product Development and Materials Engineering. The work is

part of the university’s master’s degree.

The authors are responsible for the given opinions, conclusions and results.

Supervisor: Patrik Cannmo

Credit points: 30 ECTS credits

Date:

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Figure 2.1 Chainsaw Figure 2.2 Ignition system ... 9

Figure 2.3 Aluminum Flywheel ... 9

Figure 2.4 Cold chamber HPDC machine ... 10

Figure 2.5 Hot chamber HPDC machine... 10

Figure 2.6 Metal ladling Figure 2.7 Filling process ... 11

Figure 2.8 Part ejection ... 11

Figure 2.11 Spraying process ... 12

Figure 2.9 Speed and pressure changes of the plunger during the filling in HPDC ... 12

Figure 2.10 Part Ejection... 12

Figure 2.12 The HPDC machine which used by Husqvarna AB to produce the aluminum flywheels is Buhler SC-D42 ... 13

Figure 2.13 Types of residual stresses ... 15

Figure 2.14 A schematic illustration of the contraction of a metal during solidification ... 16

Figure 2.15 Stress lattice... 16

Figure 2.16 Thermal history and stress generation-Thin sections(2) and thick section(1) ... 17

Figure 2.17 Deformation of stress lattice ... 17

Figure 2.18 Mold filling procedure... 19

Figure 2.19 Complete model of the casted component ... 20

Figure 2.20 Basic principle of hole drilling method ... 23

Figure 2.21 Types of strain gages ... 24

Figure 3.1 Geometry of the casted flywheel ... 27

Figure 3.2 Complete casting system ... 27

Figure 3.3 Casting system in pre-processor ... 28

3.4 Control points ... 29

Figure 3.5 Meshed component with 376.401 elements... 30

Figure 3.6 Meshed component with 2.502.512 elements... 30

Figure 3.7 Critical elements of different models- Coarse mesh (left), fine mesh (right) ... 31

Figure 3.8 Material definition ... 32

Figure 3.9 Shot wave profile ... 34

Figure 3.10 Temperature distribution within Ejector and Cover die before spraying ... 37

Figure 3.11 Temperature distribution within Ejector and Cover die after spraying ... 38

Figure 3.12 Temperature of the dies at single cycle process ... 38

Figure 3.13 Temperature distribution at Ejector and Cover die before spraying ... 39

Figure 3.14 Temperature distribution at Ejector and Cover die after spraying ... 39

Figure 3.15 Temperature distribution within Ejector and Cover die before spraying ... 40

Figure 3.16 Temperature distribution within Ejector and Cover die after spraying ... 40

Figure 3.17 Filling procedure ... 41

Figure 3.18 Solidification procedure ... 42

Figure 3.19 Distorted flywheel ... 43

Figure 3.20 Cooling process and stress generation ... 44

Figure 3.21 Convergence study concerning Von Misses stresses for the first four control points at depth of 0,6mm ... 45

Figure 3.22 Von Misses distribution in ambient temperature ... 46

Figure 3.23 Section where observed maximum stresses ... 46

Figure 3.24 Distribution of Maximum principle stresses ... 47

Figure 3.25 Distribution of Minimum principle stresses ... 47

Figure 3.35 Minimum Principle stresses through the hole depth at position A ... 57

Figure 3.36Maximum Principle stresses through the hole depth at position A ... 57

Figure 3.37 Von Misses stresses through the hole depth at position B ... 58

Figure 3.38Minimum Principle stresses through the hole depth at position B ... 58

Figure 3.39 Maximum Principle stresses through the hole depth at position B ... 59

Figure 4.1 Von Misses stresses through the hole depth at position A. ... 60

Figure 4.2 Von Misses stresses through the hole depth at position B. ... 61

Figure 4.3 Average value and deviation of Von Misses stresses through the hole depth at position A. 61 Figure 4.4 Average value and deviation of Von Misses stresses through the hole depth at position B.. 62

Figure 4.5 Min Principle stresses through the hole depth at position A. ... 62

Figure 4.6 Max Principle stresses through the hole depth at position A. ... 63

Figure 4.7 Min Principle stresses through the hole depth at position B. ... 63

Figure 4.8 Max Principle stresses through the hole depth at position B. ... 64

Figure 4.9 Average value and the deviation of Min and Max Principle stresses through the hole depth at position A... 64

Figure 4.10 Average value and the deviation of Min and Max Principle stresses through the hole depth at position B. ... 65

Figure 4.11 Strains distribution through the hole depth ... 66

Figure 4.12 Distribution of Von Misses stresses in the cross section area ... 67

Figure 4.13 Distribution of Min Principle stresses in the cross section area ... 67

Figure 4.14 Distribution of Max Principle stresses in the cross section area ... 68

Figure 4.15 Experimental measurement of the distorted internal rim of the flywheel ... 70

Figure 4.16 Internal rim’s measured diameter of the simulated flywheel ... 71

Figure 4.17 Von Misses stress distribution within the initial(left) and the optimized(right) model ... 72

Figure 2.1 Chainsaw Figure 2.2 Ignition system

Figure 2.5 Hot chamber HPDC machine

Figure 2.6 Metal ladling Figure 2.7 Filling process

Figure 2.11 Spraying process

Figure 2.9 Speed and pressure changes of the plunger during the filling in HPDC

Figure 2.12

The HPDC machine which used by Husqvarna AB to produce the aluminum

flywheels is Buhler SC-D42

Figure 2.14 A schematic illustration of the contraction of a metal during solidification

Figure 2.16 Thermal history and stress generation-Thin sections(2) and thick section(1)

(1)

(2)

(3)

(4)

o

o

o

o

o

o

o

(6)

(7)

(8)

Figure 3.1 Geometry of the casted flywheel

3.4

Control

points

Figure 3.5 Meshed component with 376.401 elements

Figure 3.8 Material definition

Table 3.3 Heat transfer definition

Table 3.5 Geometrical parameters

Table 3.6 Machine characteristics

Table 3.7 Filling characteristics

Figure 3.11 Temperature distribution within Ejector and Cover die after spraying

After spraying

Figure 3.13 Temperature distribution at Ejector and Cover die before spraying

After Spraying

Figure 3.15 Temperature distribution within Ejector and Cover die before spraying

Table 3.9 Solidification statistics

Figure 3.19 Distorted flywheel

Table 3.11 Convergence study

Figure 3.21 Convergence study concerning Von Misses stresses for the first four control

points at depth of 0,6mm

0 2 4 6 8 10 12 14 16 18 20 0 500000 1000000 1500000 2000000 2500000 3000000 Str e sses Vo n M isses M Pa Number of elements

.

Figure 3.22 Von Misses distribution in ambient temperature

Figure 3.24 Distribution of Maximum principle stresses

Table 3.12 Drilled position

Table 3.13 Composition of aluminum alloy

Table 3.15 Process parameters

Table 3.16 Material and strain gage properties

Drilling

Table 3.17 Raw data from measurements at position A

Figure 3.32 Strain distribution through the depth

-80 -60 -40 -20 0 20 40 60 80 0 0,5 1 1,5 2 Str ai n [1E 10 -6] Depth mm Gage 1 Gage 2 Gage 3

Figure 3.33 Strain distribution through the depth

-80 -60 -40 -20 0 20 40 60 80 0 0,5 1 1,5 2 Str ai n [1E 10 -6] Depth mm Gage 1 Gage 2 Gage 3

Figure 3.34 Von Misses stresses through the hole depth at position A

0 5 10 15 20 25 30 35 40 45 50 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Vo n M isse s M Pa Depth mm

Figure 3.35 Minimum Principle stresses through the hole depth at position A

.

-50 -40 -30 -20 -10 0 10 20 30 40 50 0 0,2 0,4 0,6 0,8 1 Sm in M Pa Depth mm

Flywheel 40 Flywheel 42 Flywheel 43 Flywheel 41a Flywheel 48a

-50 -40 -30 -20 -10 0 10 20 30 40 50 0 0,2 0,4 0,6 0,8 1 Sm ax M Pa Depth mm

Figure 3.37 Von Misses stresses through the hole depth at position B

Figure 3.38Minimum Principle stresses through the hole depth at position B

0 5 10 15 20 25 30 35 40 45 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Vo n M isses M Pa Depth mm -50 -40 -30 -20 -10 0 10 20 30 40 50 0 0,2 0,4 0,6 0,8 1 Sm in M Pa Depth mm

Figure 3.39 Maximum Principle stresses through the hole depth at position B

-50 -40 -30 -20 -10 0 10 20 30 40 50 0 0,2 0,4 0,6 0,8 1 Sm ax M Pa Depth mm

Figure 4.1 Von Misses stresses through the hole depth at position A

.

0 5 10 15 20 25 30 35 40 45 50 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Vo n M isse s M Pa Depth mm

Figure 4.2 Von Misses stresses through the hole depth at position B

.

0 5 10 15 20 25 30 35 40 45 50 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Vo n M isses M Pa Depth mm

Flywheel 44 Flywheel 45 Flywheel 46b Flywheel 47 Flywheel 49b

0 5 10 15 20 25 30 35 40 45 50 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Vo n M isses M Pa Depth mm

Figure 4.4 Average value and deviation of Von Misses stresses through the hole depth at

position B

.

Figure 4.5 Min Principle stresses through the hole depth at position A.

0 5 10 15 20 25 30 35 40 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Vo n M isse s M Pa Depth mm -50 -40 -30 -20 -10 0 10 20 30 40 50 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Sm in M Pa Depth mm

Figure 4.6 Max Principle stresses through the hole depth at position A.

Figure 4.7 Min Principle stresses through the hole depth at position B.

-50 -40 -30 -20 -10 0 10 20 30 40 50 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Sm ax M Pa Depth mm

Flywheel 40 Flywheel 42 Flywheel 43 Flywheel 41a Flywheel 48a

-50 -40 -30 -20 -10 0 10 20 30 40 50 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Sm in M Pa Depth mm

Figure 4.8 Max Principle stresses through the hole depth at position B.

Figure 4.9 Average value and the deviation of Min and Max Principle stresses through the

hole depth at position A.

-50 -40 -30 -20 -10 0 10 20 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Sm ax M Pa Depth mm -50 -40 -30 -20 -10 0 10 20 30 40 50 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Pr in ci p le str e sses M Pa Depth mm Smin Smax

Figure 4.10 Average value and the deviation of Min and Max Principle stresses through the

hole depth at position B.

-50 -40 -30 -20 -10 0 10 20 30 40 50 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 Pr in ci p le str e sses M Pa Depth mm Smin Smax

Figure 4.11 Strains distribution through the hole depth

-1000 0 1000 2000 3000 4000 5000 0 0,5 1 1,5 2 Str ai n s 1E 10 -6 Depth mm Gage 1 Gage 2 Gage 3

Figure 4.12 Distribution of Von Misses stresses in the cross section area

Figure 4.14 Distribution of Max Principle stresses in the cross section area

Table 4.1 Simulated stresses at the position A in depth 0,2 and 0,6mm

Table 4.2 Simulated stresses at the position B in depth 0,2 and 0,6mm

Table 4.3 Calculated stresses from Simulations as well as from Hole drilling measurements at

the position A

Table 4.4 Calculated stresses from Simulations as well as from Hole drilling measurements at

the position B

Figure 4.16 Internal rim’s measured diameter of the simulated flywheel

Figure 4.17 Von Misses stress distribution within the initial(left) and the optimized(right) model

Table 4.5 Calculated stresses from both Simulations at the position A

A

alignment, 67

Aluminum alloy AlSi9Cu3, 32 Aluminum flywheel, 2

C

Castings, 2

Chainsaw, 9

Chemical composition, 49 Cold chamber machine, 10 Compressive stresses, 71, 75 Control points, 68 Convergence study, 45

D

Defects, 14 Distortion, 72

E

End mill, 53

F

Feeding affectivity, 71 Filling process, 41 Flywheel, 9

H

High Pressure Die casting, 10 Hole drilling method, 22

I

Increment, 53 Integral method, 56

L

Liquidus temperature, 41

M

MAGMAhpdc, 19 Measurement techniques, 22 Mechanical properties, 50 Melt superheat temperature, 74

P

Pouring temperature, 74 Principal stresses, 46

R

Residual stress, 2 Residual stresses, 15

S

Solidification, 41 Solidus temperature, 41 Strain gage rosettes, 51

U

Uncertainty, 26

V

Von Misses stresses, 62