(b) Derive the interpolation function (Shape function) for constant strain triangular element.
(10 Marks)

9. (a) Derive the equation for 2D plane stress solid mechanic problem. (10 Marks)

(b) For the plane stress element whose co-ordinates are given by A (100,100) B (400,100)
C (200,400). The nodal displacements are ‏رہ‎ - 2mm, vi=lmm, 1221171111, v2=1.5 mm,
u3=2.5mm, v3= 0.5 mm. Determine the element stress. Assume, E = 200 GN/m2, u=0.3, t=10
mm. (10 Marks)