Local buckling theoretical calculation method of the FRP foam sandwich cylinder under axial compression

Local buckling is often a main failure form of the FRP (Fiber Reinforced Plastic) foam sandwich cylinder under axial compression. In order to study its local buckling behavior under axial compression, axial compression test on the FRP foam sandwich cylinder was conducted in this paper, and two types of local buckling, i.e. local conjoint buckling and local layered buckling, were revealed. Then, based on Reissner’s first-order shear theory of laminated cylinder, the theoretical solution of local conjoint buckling force of this kind of member was derived; and by establishing the model of laminated cylinder on Pasternak foundation, the theoretical solution of local layered buckling force of this kind of member under axial compression was derived. The theoretical results were compared with the results obtained by FE buckling analysis and by the test, which verifies the applicability of the theoretical calculation method to ideal FRP foam sandwich cylinder. For actual FRP foam sandwich cylinder with initial defects, the defect factor for the theoretical solution was suggested.