Abstract:When the extension-twist multicoupled laminate is used to construct a bending-twist coupling structure, the panel on the inside of the bend will be subjected to compressive load, and buckling instability will occur when the compressive load reaches a critical value, which weakens the bearing capacity of the structure. Therefore, in order to improve the theoretical basis of the design of the bending-twist coupling structure, the analytical solution of the critical buckling load of the four-sided simply supported extension-twist multicoupled laminate under in-plane compressive load was obtained by using the double triangular series method. With the maximum buckling load and coupling effect as the optimization objectives, a multi-objective optimization design model based on the weight coefficient method was established, and the sequential quadratic programming method (SQP algorithm) was used to complete the optimization, and the laminate with greater coupling effect and bearing capacity was designed. Based on the layup law of the optimal laminate, the numerical simulation verification and robustness analysis of the buckling analysis model were completed. The analysis results show that the deviation between the analytical results and the simulation results of the buckling load of the laminate is within 5%. This method has high accuracy and provides a new idea for the buckling analysis of composite laminates. Finally, the multi-directional loading testing machine was used to complete the experimental measurement of the buckling load of the tensile torsion-multi-coupling effect laminate laminates, and the error between the measured value and the theoretical value was within 3%, which verified the correctness of the theory.