For the properties given in Table 1, and Poisson Ratio, nu , of 0.497, Ku  = 19.6 x 106  psi, which is greater than the elastic modulus of Aluminum, a = 1.85. The Bulk yield stress of Urethane, kyu is 998 x 103 psi, which is more than eighty times its unconfined yield stress syu of 12 x 103 psi. The bending moment of the inertia of the empty tube is Ie is 0.028658 inches4, and the bending moment of the urethane-filled tube, If , is 0.12976 inches4.

            The dimensional specification of the four test articles are provided in Table 2