Optimization of the initial post-buckling response of trusses and frames by an asymptotic approach

TL;DR

This paper applies asymptotic post-buckling theory to optimize the initial post-buckling response of trusses and frames, improving design robustness and nonlinear performance approximation.

Contribution

It introduces a method to control post-buckling behavior by including asymptotic coefficients in the optimization process, reducing sensitivity to imperfections.

Findings

Effective control of post-buckling response through asymptotic coefficients

Reduction in imperfection sensitivity of optimized designs

Successful application to compliance minimization in trusses and frames

Abstract

Asymptotic post-buckling theory is applied to sizing and topology optimization of trusses and frames, exploring its potential and current computational difficulties. We show that a designs' post-buckling response can be controlled by including the lowest two asymptotic coefficients, representing the initial post-buckling slope and curvature, in the optimization formulation. This also reduces the imperfection sensitivity of the optimized design. The asymptotic expansion can further be used to approximate the structural nonlinear response, and then to optimize for a given measure of the nonlinear mechanical performance such as, for example, end-compliance or complementary work. Examples of linear and nonlinear compliance minimization of trusses and frames show the effective use of the asymptotic method for including post-buckling constraints in structural optimization.