NUMERICAL ANALYSIS OF STABILITY BOUNDARY ON ELASTIC STRUCTURES UNDER COMBINED LOADS BY A PERTURBATION METHOD

Abstract

Varying several parameters such as loads, sectional properties, material and etc. in a structural system, the stability boundary is represented as the locus of critical points on the equilibrium path. We propose a computational method, in which the perturbation procedure is utilized, for tracing stability boundary on elastic structures under combined loads. The determinant of tangent stiffness matrix can be expressed as the product of its eigenvalues. The fundamental condition is an equation that the determinant, which is represented by the perturbation coefficients of eigenvalues, vanishes. Numerical results show that the proposed method can trace the stability boundary for elastic structural systems accurately.