Buckling and post-buckling analysis of composite laminates with cutout under compressional loading based on the first-order shear deformation theory

The optimal design of multilayer substrates containing the cutout under compressive loads is fundamental to achieving maximum buckling resistance compared to structural weight, especially in aerospace structures. In this study, buckling and post-buckling behavior of composite laminated plates with orthogonal and symmetrical lay-up containing cutouts with different diameters have been investigated experimentally, semi-analytically, and numerically. Based on the first-order shear deformation theory, a finite strip method is developed to study the buckling of the composite laminates with cutout semi-analytically. A finite element method was used for numerical analysis. The required mechanical properties were obtained from standard tests. The current study results show that the size of the cutout diameter doesn't have a considerable effect on the elastic rigidity of the plate. Still, the buckling load decreases significantly by increasing the cutout diameter. Also, the plate's buckling load and elastic rigidity are increased considerably by increasing the number of composite layers. The thickness of the plate has more effect on the buckling load than the diameter of the cutout. The present study shows a good correlation between the results of buckling behavior derived from semi-analytical and finite element methods with experimental results.