Analysis of a viscoplastic plate subjected to rapid external heating

Abstract

A computational analysis is presented herein for an axisymmetric plate subjected to rapid external heating. The analysis is complicated by several forms of nonlinearity, including radiation boundary conditions, material viscoplasticity and geometric nonlinearity. The mechanical constitution is extremely complex, involving history and rate dependence which causes the constitutive equations to be mathematically stiff. Results are obtained for two viscoplasticity models available in the current literature. The solution utilized herein adopts the finite element method in spatial coordinates and standard finite differencing in time. Iterative techniques are used to account for nonlinearity. Results are obtained for a circular plate subjected to a high energy instantaneous heat source applied axisymmetrically to one side of the plate. Sensitivity studies are conducted to determine the effects of various heat intensities and plate thicknesses on temperature, displacements, and stresses. It is found that material viscoplasticity and geometric nonlinearity contribute significantly to the predicted response of the plate.