Dynamic buckling of an imperfect elastic, visco-plastic plate

Finite element analyses of dynamic buckling of an initially pre-bent plate are compared with static and dynamic experiments on type II columns investi gated by Tam and Calladine (Int J Impact Engng 1991;11: 349-77). We employ an elastic-visco-plastic material model of the Cowper-Symonds type, which i ncludes the measured quasi-static effective-stress plastic-strain curve. Th e striker is represented by a point mass impacting a contact surface on the end of a plate. The analysis considers models composed of two-dimensional beam- and three-dimensional shell-elements and discusses the effects caused by the finite width of the plate, the strain- and strain-rate hardening ma terial properties and inertia. The calculated static and dynamic response i s in good agreement with the experimental curves. Having shown the accuracy of our finite element model, the effect of the impact velocity on the stru ctural response is analysed. (C) 2000 Elsevier Science Ltd. All rights rese rved.