Isogeometric vibration and buckling analyses of curvilinearly stiffened composite laminates

Isogeometric analysis (IGA) with the polynomial splines over hierarchical T-meshes (PHT-splines) is used to provide an efficient tool capable of carrying out the vibration and buckling analyses of the stiffened laminates. IGA offers increased accuracy and efficiency using the PHT-splines, which represent exact geometry of the stiffeners and make the refinement more flexible near the areas where the stiffeners and composite plate are connected. Numerical examples are given to validate the correctness and superiority of the present method, comparing with the results from existing literatures and commercial softwares. Besides, the influences of the orientation, curvature, location and cross-section size of the stiffeners on the natural frequencies and buckling loads are also studied. The results show that the optimization of the shape and size of the stiffeners has an important effect on the vibration and buckling characteristics of stiffened laminates.