The MINLP optimisation of composite I-beams

摘要

The paper presents the optimization of composite I-beams, designed to be connected together from structural steel I sections and reinforced concrete slabs. The optimization of composite beams has been performed by the Mixed-Integer Non-linear Programming (MINLP) approach. The MINLP performs a discrete optimization of different materials and standard dimensions, while continuous parameters are simultaneously calculated inside the continuous space. As the discrete/continuous optimization problem of the composite beams is non-convex and highly non-linear, the Modified Outer-Approximation/Equality-Relaxation (OA/ER) algorithm has been used for the optimization. The accompanied Linked Two-Phased MINLP Strategy accelerated the convergence of the mentioned algorithm.