Integrated framework for optimizing the viscoelastic response of laminated composites under hygrothermal conditions

This study introduces an innovative computational framework aimed at optimizing the stacking sequences and thickness of laminated composite structures to achieve optimal viscoelastic responses under various hygrothermal conditions. It is worth noting that computational work for viscoelastic problems typically demands substantial effort and time due to repetitive numerical steps. When incorporating optimization into these problems, the computational requirements increase considerably, making traditional methods less suitable for practical engineering applications. Therefore, the present framework utilizes a smoothed finite element technique named smoothed cell element-discrete shear gap with fast convergence. To reduce the computational workload and avoid the recursive algorithm of viscoelasticity, the computational processes are performed in the transformed Laplace domain to linearize the stress–strain relationship in an integral form. Moreover, the framework is integrated with the balance-enhanced symbiotic organism search algorithm, a robust metaheuristic, to create an efficient optimization computational framework. Through systematic analysis, this research contributes to the advancement of composite material design by offering a practical and effective solution for addressing both viscoelastic behavior and hygrothermal considerations in thin laminated structures.