Integrated design for the forming process and structural performance of variable-thickness laminates

The manufacturing process of composite laminated parts has a significant influence on the final performance, especially since the draping process can change the predefined fiber orientation at local sites. With the maturing of draping-process simulation technology, an integrated structure-process-performance design has become possible. This article reports a computational framework for the integrated design of the draping process and structural performance of variable-thickness (VT) laminates. The framework is a two-loop optimization workflow. Specifically, a genetic draping optimization method features the inner optimization loop to find the optimal draping strategy and obtain the resulting fiber orientations and manufacturing layout. Structural performance optimization outlines the outer optimization loop, where a parametric method for the physical configuration of VT laminates is proposed to evaluate the structural performance considering the draping strategy. The entire framework is demonstrated by an automotive B-pillar reinforcement. The benefits of incorporating the draping design versus no draping design are illustrated by comparing the corresponding design results. The comparison results show that the integrated design not only contributes to pretreating manufacturing defects but also allows the use of reoriented fiber directions caused by draping to improve the mechanical properties and engage the load bearing. It thus achieves a further weight reduction of 18.63%. This framework facilitates resource-friendly process design, comprehensive performance evaluation, and structurally efficient laminate design.