Assigned 9-14-06; Due 9-21-06

(a.) Use hand calculation methods to solve for the displacements at node 1 in the TRUSS1 problem described below. Equilibrium and compatility equations should be used to assemble the global stiffness matrix.

Cross sectional area A = 0.5 in^2, Elastic Modulus E = 3.e7 lbf/in^2

For the cases below the material is an isotropic steel.

(b.) The normal strains are

e_x = 300 x 10^-6 in/in, e_y = -200 x 10^-6 in/in , e_z = 0

Find the normal stresses s_x ,s_y ,s_z

(c.) The normal stresses are

s_x = 20,000 psi, s_y = -35,000 psi, s_z = 0

Find the normal strains e_x, e_y, e_z