STABILITY OF EQUILIBRIUM AND COMPATIBILITY OF STRUCTURES WITH UNIAXIAL MATERIAL BEHAVIOUR

Abstract

A generalization of the stability analysis is presented: analogously to the stability analysis of equilibrium, based on the potential energy, stability analysis of compatibility, based on the complementary energy will be introduced. Nonlinearly inelastic material is considered, excluding strain softening and damage but including strain hardening and locking. The concept of tangent and compliance modulus is applied. Global stability analysis is investigated, related to the total domain of the state variables,distinguishing the dead and rigid type of load, and their relation with the basic variational principles. Discrete structural model of frame structures with uniaxial nonlinear and nonelastic material behaviour will be analysed. Numerical illustrations can be studied in the author's papers, in (KURUTZ 1989, 1993, 1994).