Large Deformations and Tearing of Circular Plates and Plate-Tube Structural Combinations under Impulsive Loading

Abstract

Response of circular plates under transverse impulsive load time history using a transient dynamic finite element analysis methodology employing progressive degradation has been presented. Experimental results by Nurick et al. for the prediction of onset of thinning and subsequent tearing at the boundary of clamped circular plates subjected to uniformly loaded air blasts have been used to compare and validate the FE model and simulation procedure in ANSYS. The Mode II failure in respect of clamped circular plates has been simulated using a rupture strain criteria. Mode III failure of plastic shear sliding has been considered with a shear strain failure model as proposed by Wen et al. where in the circular plate parameters have been used. A progressive degradation approach employing a stiffness reduction scheme under the FE model setup has been proposed to simulate the initiation and progression of tearing in conjunction with a suitable failure model under mode II and mode III failure. The evolution of deflections, plastic zones, rupture zones and failure modes under the blast loading conditions are found to be in very good correlation with the experimental results of Nurick et al.