Use of substructuring in non‐linear material analysis

Abstract

The latest release of the stress analysis finite element system BERSAFE contains a new general substructuring facility for use in either elastic or non‐linear analysis. The technique allows a considerable extension to the available facilities in that parts of the structure can be stored on datafiles for current or subsequent use. In the latter case, repeated computations are avoided for components with identical geometric and material properties, so effectively larger problems can be solved without a proportional increase in cost and effort. For non‐linear analysis, the technique is well suited to cases where non‐linear behaviour is confined to certain parts of the structure, such as in the vicinity of stress concentrations and crack tips. The elastic areas can be replaced by a substructure boundary, thereby concentrating the analysis on the higher‐stressed portions of the structure and so reducing the extent and cost of each iteration. The non‐linear substructuring technique is described in detail and illustrated by examples.