Shear Buckling Analysis and Optimization of Composite Laminates Using Perturbation GDQ Method

There was poor accuracy, calculation oscillation and non-convergence for the cases of shear buckling responses of composite laminates by using GDQ method. The example study found that the problems came from the singular load matrix, therefore, the perturbation GDQ method was proposed to realize the stable and efficient solution of shear buckling problems for composite laminates, by disturbing the main diagonal weight coefficients to improve the singularity of the load matrix. Numerical examples demonstrate the validity of the perturbed GDQ method. The stacking sequence of composite laminates including shear loads was optimized combined perturbation GDQ method with the direct search simulated annealing algorithm. The results show that the ply numbers and lay forms of composite laminates have little effects on the optimum ply under shear loads, and optimized layup angle tends to 60° with the increasing of aspect ratio. Under combined loads of shear and axial compression, the relatively small shear forces may improve the buckling behavior of laminates, while the optimized buckling performances are gradually reduced and the optimum ply is converged to the ply of shear loads with the increasing of shear forces. The results provide a reference for the shear buckling performance design of composite laminates. © 2019, China Mechanical Engineering Magazine Office. All right reserved.