Optimal design of damage tolerant composite using ply angle dispersion and enhanced bat algorithm

Abstract

In this work, minimum weight optimization of laminated composite is performed using a newly developed enhanced bat algorithm (EBA). Bat algorithm (BA) is a recently developed swarm-based optimization technique which is inspired by the echolocation behavior of bats. The standard BA shows premature convergence and reduced convergence speeds under some conditions. So, the EBA is used to perform the design optimization of laminated composites. The laminate analysis based on classical laminate theory is utilized for the stress calculations. Tsai–Wu failure curve is considered as the constraint in this constrained optimization problem. Number of plies at each orientation angle are considered as the design variables. The design optimization has been carried out for both conventional and unconventional (dispersed plies) stacking sequences considering different loading configurations: uniaxial tension, biaxial tension with and without shear loadings. Ply angles dispersed in the range of $$5^{\circ }$$–$$85^{\circ }$$, $$25^{\circ }$$–$$65^{\circ }$$ and $$0^{\circ }$$–$$90^{\circ }$$ at intervals of $$5^{\circ }$$ are considered for the unconventional stacking sequence to increase damage tolerance. In addition, a new mathematical function is proposed to measure the dispersion of ply angles in the laminate called the dispersion function. Also, the performance of EBA is compared with standard BA in the optimum weight design of composite laminates.