EFFECTS OF GEOMETRY AND STACKING SEQUENCE ON APPARENT POISSON'S RATIO OF QUASI-ISOTROPIC LAMINATE CFRPS UNDER THE COMPRESSION TESTS

摘要

To propose reasonable conditions for measuring the Poisson's ratio of a quasi-isotropic laminate plate, experimental compressive tests and finite element analyses were performed. The effects of specimen geometry and stacking sequence on the Poisson's ratio of a quasi-isotropic carbon-fiber-reinforced polymer laminate were experimentally examined by compression tests. In particular, the divergence of the apparent Poisson's ratio from a theoretical value was experimentally measured for a decreasing specimen width/thickness ratio (b/t). The observed tendency was subsequently confirmed by simulations using finite element analysis (FEA). FEA was performed using a three-dimensional model of the specimens to investigate the strain and stress distribution. Moreover, in the evaluation of the apparent Poisson's ratio, the width direction strain was confirmed to vary under a low b/t. The FEA results confirmed that the cause of the changes to the width strain was the cross-sectional deformation under compressive loading, resulting from differences in the layer angles and stiffness between the outermost and inner layers.