Weld induced residual stress
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Transcript of Weld induced residual stress
P. R. Gautham 20061235
P. Jagadeesan 20061241
M. Lokesh Babu 20061251
V. Mani 20061254
Guided by Mr. A. Vinoth Jebaraj, TRA
To calculate the deformations in the weld zone due to longitudinal residual stresses in the direction of welding process by contour method
To create a finite element model and validate the residual stresses
Selection of welding materials for analysis -AISI 304 (base) & AISI 308 (filler)
Choosing the plates (ASTM & AWS standards)
Cutting the welded work piece by EDM
Measuring the deformations in the cut surface profile by CMM
Determination of deformation using contour method(MATLAB)
Predicting the residual stresses using finite element model.
‘‘If a cracked body subject to external loading or prescribed displacements at the boundary has forces applied to the crack surfaces to close the crack together, these forces must be equivalent to the stress distribution in an uncracked body of the same geometry subject to the same external loading’’
FINITE ELEMENT MODELDEFOREMED SURFACE
INPUT DEFORMATION IN FEA TO MEASURE RESIDUAL STRESS
Wire EDM machine (Electric DischargeMachining) is chosen for the followingreasons
Uses an electrically charged wire
A spark jumps from the wire to the work piece
Material is locally vaporized
The wire never contacts the part
Puts in virtually no stress if cut in "skim cut" mode
Manual tungsten inert gas(argon) welding
5X5 weld, bevel angle 70°
Two strokes of welding
Brass wire of Ф .25 mm
Power input: 60 VX1.2 A DC
Machine speed: 1.3 mm/min 0.1 mm/min
z= p00 + p10x + p01y + p11xy + p02y2 + p12xy2+ p03y3
+p13xy3 + p04y4 + p14xy4 + p05y5
Coefficient Plate 1 Plate 2
p00 -0.05156 -0.01996
p10 -0.000567 5.995e-005
p01 -0.002305 0.005262
p11 -4.483e-005 0.000101
p02 4.098e-005 -0.0001518
p12 4.594e-007 -3.492e-006
p03 1.034e-006 -1.078e-006
p13 2.031e-008 -2.484e-008
p04 -1.289e-008 2.495e-008
p14 -1.422e-010 5.649e-010
p05 -5.985e-012 -6.267e-011
z= p00 + p10x + p01y + p20x2 + p11xy + p30x3 + p21x2y +p40x4 + p31x3y + p50x5+ p41x4y
Coefficient Plate 1 Plate 2
p00 -0.004137 0.01428
p10 0.001526 -0.003926
p01 2.743e-005 0.004601
p20 6.139e-005 -0.0006558
P11 -0.0001527 0.001223
p30 1.287e-006 -3.216e-005
p21 -2.103e-005 9.553e-005
p40 -1.661e-008 -6.882e-007
p31 -6.491e-007 2.857e-006
p50 -5.173e-010 -5.401e-009
p41 -5.709e-009 2.777e-008
z(x,y)= [zplate1(x,y)+zplate2(x,y)]/2
Temperature(C) Yield Stress (GPa) Young’s Modulus(GPa) Yield Strain
0 .256 199 1.28e-3
100 .218 193 1.179e-3
200 .186 185 1.005e-3
400 .155 167 9.28e-4
600 .149 159 9.37e-4
800 .091 157 6.026e-4
1200 .025 60 4.166e-4
1300 .021 20 1.05e-3
1550 .010 10 1e-3
Temperature Yield Stress Young’s Modulus Yield Strain
0 .370 180 2.055e-3
100 .342 175 1.954e-3
200 .326 170 1.9176e-3
400 .315 160 1.968e-3
600 .187 140 1.3357e-3
800 .150 125 1.2e-3
1000 .035 90 3.88e-4
1200 .020 60 3.333e-4
1400 .010 20 5e-4
1550 .010 20 5e-4
Prime MB, Hill MR, Dewald AJ, Sebring RJ, Dave VR, Cola MJ(2003). Residual stress mapping in welds using the contour method.
N. Murugan, R. Narayanan (2008) Finite element simulation of residual stresses and their measurement by contour method
Ueda Y, Takahashi E, Fukuda K, Nakacho K(1974). Transient and residual stresses in multipass welds.
Goldak J, Oddy A, McDill M, Chakravarti A, Bibby M, House R(1986). Progress in computing residual stress and strain in welds.
Brickstad B, Josefson BL (1998). A parametric study of residual stresses in multi pass butt-welded stainless steel pipes.