validation of riveting process

Validation of Riveting Validation of Riveting process process

Validation of Riveting Validation of Riveting process process

--AshutoshAshutosh SrivastavaSrivastava--GunjanGunjan VermaVerma

--VinayVinay CarpenterCarpenter

--AshutoshAshutosh SrivastavaSrivastava--GunjanGunjan VermaVerma

--VinayVinay CarpenterCarpenter

© 2010 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary© 2010 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary

Problem Statement

• Objective:

To benchmark riveting process in ANSYS with the experimental results[1].

• To simulate a riveting process.

– A rivet is driven into sheet joint

© 2010 ANSYS, Inc. All rights reserved. 2 ANSYS, Inc. Proprietary

– A rivet is driven into sheet joint

– Other end of the rivet is constraint using a rigid support

• Output

– Dmax, diameter of the bulge

– H, Final protruding height

[1] Amarendra, .A (2006), “A Finite Element and Experimental Investigation on the Fatigue of Riveted Lap Joints in Aircraft Applications,” Phd Thesis, School of Mechanical Engineering, GeorgiaInstitute of Technology.

Problem Configuration

Top View of plates Rivet Close-up


Top View of plates

Side View of specimen

Rivet Close-up

Geometry

Punch

Rivet

Bottom Plate 2mm thick3.175

11

.9


Bottom Plate 2mm thick

Top Plate 2mm thick

34.95.475

11

.9

14

.2

All Dimensions are in mm

Material definition

Following material properties were used for the respective parts:

• Rivet : 21174-T4 AL Alloy

• Sheet 2024-T3 Al Alloy

A tabulated stress strain input data was provide based on the equation given below:

σtrue = C(εtruem)

Isotropic hardening was considering during the simulation


Isotropic hardening was considering during the simulation

Material Elastic Properties Flow Stress Parameters

Young’s

Modulus (GPa)

Poisson’

s ratio

Strain Range C (MPa) m

21174-T4 AL 71.7 0.33 εy≤εtrue≤3 551.58[2,3] 0.15[2,3]

2024-T3 AL 72.4 0.33 εy≤εtrue≤0.02 765[1] 0.14[1]

0.02≤εtrue≤3 744[1] 0.164[1]

[1] Amarendra, .A (2006), “A Finite Element and Experimental Investigation on the Fatigue of Riveted Lap Joints in Aircraft Applications,” Phd Thesis, School of Mechanical Engineering, GeorgiaInstitute of Technology.[2] Szolwinski, M.P., Farris, T.N. (2000). “Linking riveting process parameters to the fatigue performance of riveted aircraft structures,” Journal of Aircraft, Vol.37, No.1, pp. 130-135.[3] Bajracharya,. B (2006),“Effect of Variations of Riveting Process on The Quality of Riveted Joints,” Masters Thesis, Department of Industrial and Manufacturing, Wichita State University.

Material definition contd..

4.00E+08

5.00E+08

6.00E+08

7.00E+08

Str

es

s (

Pa

)

Hardening curve 21174-T4 AL alloy


0.00E+00

1.00E+08

2.00E+08

3.00E+08

4.00E+08

-0.50 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50

Str

es

s (

Pa

)

Plastic Strain (mm/mm)

Material definition contd..

6.00E+08

7.00E+08

8.00E+08

9.00E+08

1.00E+09

Str

es

s (

Pa

)

Hardening curve 2024-T3 AL alloy


0.00E+00

1.00E+08

2.00E+08

3.00E+08

4.00E+08

5.00E+08

-0.5 0 0.5 1 1.5 2 2.5 3 3.5

Str

es

s (

Pa

)

Plastic Strain (mm/mm)

Boundary Conditions

Fix X direction displacement on rivet edge

Fix X direction displacement & apply displacement in Y direction to the puncher


Fix Y direction displacement at plates side

Fix Y direction displacement at rivet head

Analysis Settings and procedure

• Load was applied gradually in two steps.

– In the first step predetermined displacement was applied

– In the second step the punch was displaced in reverse direction to simulate spring-back action of the rivet.

• All contacts were considered as frictional contact (frictional coefficient as 0.2) except the one between the plates which was assumed as


as 0.2) except the one between the plates which was assumed as bonded for simplicity.

• Force probe was used to determine the squeeze force.

• Load displacement graph was plotted for each case.

RESULTS


RESULTS

UX Direction Displacement


F = 26.9 KNDmax = 8.6454mm

F = 35.67 KNDmax = 9.6108mm

F = 45.02 KNDmax = 10.3766mm

F = 53.804 KNDmax = 10.9426mm

UY Direction Displacement


F = 26.9 KN

H = 5.796mm

F = 35.67 KN

H = 4.66mm

F = 45.02 KN

H = 3.93mm

F = 53.804 KN

H = 3.46mm

Dmax Result Comparison

8.5

9

9.5

10

10.5

11

11.5

Dm

ax

(mm

)

Dmax Result Comparison

ANSYS

Exp


8

25 30 35 40 45 50 55 60

Squeeze Force (KN)Squeeze Force,ANSYS

(KN)

Squeeze Force,

Exp[1] (KN)

Dmax(mm) Ansys

Dmax(mm) Exp[1]

% diff(ANSYS)

26.90 26.69 8.6454 8.559 1.01

35.67 35.56 9.6108 9.525 0.9

45.02 44.48 10.3766 10.16 2.13

53.80 53.37 10.9426 10.795 1.37


Final Protruding Height Comparison

3.5

4

4.5

5

5.5

6

Pro

tru

din

g H

eig

ht

(mm

)

Protruding Height (H) Comparison

ANSYS

Exp


3

25 35 45 55 65

Squeeze Force (KN)Squeeze Force,ANSYS

(KN)

Squeeze Force,

Exp[1] (KN)

H (mm)Ansys

H (mm) Exp[1]

% diff(ANSYS)

26.90 26.69 5.797 5.796 0.017

35.67 35.56 4.66 4.59 1.53

45.02 44.48 3.93 4 1.75

53.80 53.37 3.46 3.49 0.86


Conclusion

• The whole process was setup in workbench environment without any assistance of command snippet.

• All the four cases were setup in a single project format, thus eliminating the need of four different files.

• ANSYS numerical results match with experimental results


• ANSYS numerical results match with experimental results well within the norms

– A maximum difference of 2.13% was observed for the final deformed rivet diameter.

– A maximum difference of 1.75% was observed for the final protruding height

Refrences:

[1] Amarendra, .A (2006), “A Finite Element and Experimental Investigation on

the Fatigue of Riveted Lap Joints in Aircraft Applications,” Phd Thesis,School of Mechanical Engineering, Georgia Institute of Technology.

[2] Szolwinski, M.P., Farris, T.N. (2000). “Linking riveting process parameters

to the fatigue performance of riveted aircraft structures,” Journal of Aircraft,Vol.37, No.1, pp. 130-135.


Vol.37, No.1, pp. 130-135.

[3] Bajracharya,. B (2006),“Effect of Variations of Riveting Process on The

Quality of Riveted Joints,” Masters Thesis, Department of Industrial andManufacturing, Wichita State University.