Direct computation of instability points with inequality constraints using the Finite Element Method

Summary

The objective of this monograph is to apply the computation methods for critical points to more complex mechanical problems involving inequality constraints. Prior to this extension to a new class of problems appropriate methods among the existing ones for the critical point detection are chosen. Therefore the CDM and the extended system as the most primising techniques will be compared and evaluated.

A one step prediction of the critical load based on the extended system will be developed that enables a better evaluation. The possibilities of a combination of both methods will be examined. A conceivable combination is to use the prediction of a CDM computation as starting value for the extended system and enhance the convergence of the latter.

In a second step critical point detection methods are extended to problems that involve inequality constraints. In this context constitutive damage models and contact problems are studied.