Imperfection-Sensitive Overall Buckling of Single-Layer Lattice Domes

In this paper, the effects of geometric imperfections on the nonlinear buckling behavior of rigidly jointed single-layer lattice domes under vertical loading have been studied. A commercially available finite-element code has been used. Numerical experiments using varying levels of imperfection, chosen to be of the same forms as various linear buckling eigenmodes, have demonstrated the complexity of the buckling behavior. Lower bounds to the imperfection sensitivity of elastic overall buckling loads have been shown to result from the reduced stiffness analysis which is a simple extension to the classical linear buckling analysis. In addition an alternative elastic and plastic interaction empirical formula based upon the reduced stiffness loads has been seen to predict the lower bounds in the relatively large level of geometric imperfections.