NUMERICAL ASPECTS OF DYNAMIC, GEOMETRICALLY NON-LINEAR CALCULATIONS OF ELASTO-VISCOPLASTIC PLATES

Abstract

In the paper numerical aspects of elasto-viscoplastic dynamic calculations of circular plates are presented. Numerical results are compared with experiments carried out in the laboratory. Each plate is calculated using the self-built computer program based on the finite element method. The Gaussian quadtrature is used for the surface integration and some difficulties concerning the choice of the order of this integration are discussed. To integrate the constitutive equations (the first order differential equations), and the equations of motion (the second order differential equations), it is necessary to use proper value of the time step. Some remarks on selection of this value are given. Density of the finite element mesh used for discretisation of the plate is studied. It was found that the number of elements has bigger influence on the quality of the results than the number of layers used to describe the changes of stresses through the thickness of the plate. Finally, some comments on the choice of the model of damping are made. An approximate method of introduction of this factor in the calculations is presented.