Solution of coupled mechanical behavior of bending-twisting coupled box structure based on multi-coupled laminates

The coupled mechanical behavior of composite bending-twisting coupled structure has still not been solved completely and effectively. In this paper, the analytical stiffness equation is derived for the bending-twisting coupled box structure with web, including the box structure composed of extension-shearing coupled laminate and the box structure composed of multi-coupled laminates. By combining deep learning with analytical deri-vation, the problem of accuracy deviation of analytical model introduced by boundary conditions is skillfully solved, and then the high-precision analytical solution of torsional deformation of box structure is realized. Based on the analytical model, the optimal design of the box structure is further realized. The results show that compared with the box structure composed of extension-shearing coupled laminate, the box structure designed by the multi-coupled laminates is able to reach higher bending-twisting coupling (up to 80%). Finally, the robustness of the couplings of laminates and box structures are analyzed respectively, and the hygrothermal stability and couplings of the box structure are verified by numerical simulation.