Elastic-Plastic Analysis by Integrated Local Petrov-Galerkin Sinc Method

Elastic and elastic―plastic analyses of tensioned panels with an elliptical center notch are performed using the integrated local Petrov―Galerkin sinc method. The method is extended for analysis of boundary-value problems for nonlinear materials. The integrated local Petrov―Galerkin sinc method is used to obtain stress concentrations and stress intensities, using the J integral for both elastic and elastic―plastic plane-stress panels. The material is assumed to behave in a bilinear manner with kinematic hardening. The results are compared with the analytic solution for an infinite elastic panel in tension and with a finite-element solution for the panel with material nonlinearity. Good correlation is seen with stress concentration; although, the method tends to overestimate the stress concentrations. The nonlinear results compare well with the finite-element results. The accuracy deteriorates as the plastic zone propagates into areas less densely populated by the sinc points. For the elastic―plastic material, the J integral was estimated within 5 % of the finite-element result, using the integrated local Petrov―Galerkin sinc method.