Multi-objective modified heat transfer search for truss optimization

In this article, a modified version of heat transfer search (HTS) is proposed for multi-objective structural optimization. Contrary to the basic HTS optimizer which activates only one of the three phases of HTS at a time, multi-objective HTS simultaneously exploits the effect of all phases. The proposed modified optimizer is based on the principle of thermodynamics with design solutions being thought of molecules that interact with other molecules of the system itself, and simultaneously with the surrounding molecules through the three modes of heat transfer, namely conduction, convection, and radiation phases. To examine the effectiveness and feasibility of the proposed modification, five truss optimization benchmark problems are used for the performance test. Truss mass minimization and nodal displacement maximization are taken as objectives, while design variables are discrete. The new method along with several recent multi-objective meta-heuristics including ant system, ant colony system, symbiotic organism search, and HTS is used to solve the test problems and compared for the hypervolume and spacing-to-extent indicators. The results reveal that the improved version of HTS is superior to its previous version and the other optimizers. The statistical examination of this study has been performed by conducting Friedman’s rank. Results show the dominance of the proposed optimizer performance in comparison with the others.