Numerical study of the effect of compression-shear load ratio on the failure behavior of CFRP laminated plate

Carbon fiber reinforced polymer (CFRP) composite laminated plates are commonly used structures in the aircraft. Under in-plane compression-shear loads, the failure of laminated plates is affected by both buckling and material damage, and the failure forms are complex and variable. In this paper, a progressive damage analysis method was established considering the in-situ effect, the influence of transverse stress on shear strength, and the shear nonlinearity of the material. The compression-shear test was carried out to validate the proposed method. Based on the validated method, the failure behavior of the CFRP plates with different compression-shear load ratios was investigated based on the finite element model. It is shown that when the compression-shear loads ratio is low, the initial material damage of the plate occurs first, and then the maximum load is reached. When the load ratio is high, buckling occurs directly, and at the same time, the maximum load is reached without material damage. When the load ratio is in between, material damage occurs first, then buckling occurs and maximum load is reached. In addition, the change of compression-shear load ratio will also have an effect on the compression and shear load bearing capacity of the plate, and the damage extension degree of the plate when the maximum load is reached.