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.