A Thermoplastic BEM Analysis for Substructured Axisymmetric Bodies

Abstract

A boundary element formulation for thermoplastic analysis of axisymmetric bodies subjected to axisymmetric loads is developed. This formulation is implemented in a multiregion system that utilizes quadratic isoparametric shape functions to model the geometry and field variables of the boundary and domain of a body. The kernel functions are presented in an appendix and the singularities associated with these kernels are discussed. New techniques are described to calculate the coefficients associated with the singular nodes. An iterative procedure known as the initial stress algorithm is adopted for the incremental thermoplastic analysis. An advanced implementation of the algorithm includes a time‐saving feature which reduces the number of iterations needed for convergence by utilizing the past history of initial stress rates to estimate the values of the initial stress rates of the next load increment.