DYNAMIC INSTABILITY ANALYSIS OF ELASTIC AND INELASTIC SHELLS

The present contribution is concerned with dynamic stability investiga tions of arbitrary structural responses, in particular shell responses . In order to trace such nonlinear fundamental processes, incremental/ literative path-following algorithms are employed to the tangential eq uation of motion which is derived under special regard of finite rotat ion shell theories, elasto-plastic material behaviour, and motion-depe ndent loading. Occuring instabilities can be detected with the help of Lyapunow exponents as generalized concept for the detection of quanti tative stability properties. Well known investigation procedures are r ecognized as special cases of the Lyapunow-exponent-concept for statio nary, transient, periodic, and arbitrary solution curves in the phase space; A new numerical procedure for the determination of one-dimensio nal Lyapunow exponents is introduced to identify critical directions i n the solution space for large discretized structures by reduction to relevant manifolds.