ABSTRACT
Due to time constraints on structural design processes, modelling and computational complexity is often a key concern in limit state analysis of reinforced concrete (RC) structures, causing practitioners to choose efficient but inaccurate methods of analysis over more advanced ones. Recently, a framework using convex optimization for elasto-plastic, geometrically linear analysis of RC walls was proposed, enabling analysis of models with more than 10,000 finite elements within minutes on a standard PC. In order to improve the applicability and relevance of the framework as a design tool, this paper proposes an extension that enables the determination of the critical buckling load. Based on the nonlinear solution obtained from the elasto-plastic optimization problem, the cracked tangent stiffness of the RC sections is determined, and a linearized buckling problem is posed and solved as a linear eigenvalue problem. This allows the actual critical buckling load to be determined by solving a sequence of optimization and eigenvalue problems. The accuracy of the proposed method is assessed, and its applicability to practical design scenarios is demonstrated by an analysis of an RC wall with a door hole, showing an average solution time of approximately 30 seconds per load step.
