2D and 3D interlaminar fracture assessment under mixed-mode loading conditions

In this paper, the mixed-mode interlaminar fracture behavior of woven carbon-epoxy composite was investigated based on experimental and numerical analyses. A modified version of Arcan specimen was employed to conduct a mixed-mode fracture test using a special loading device. A full range of mixed-mode loading conditions including pure mode-I and pure mode-II loading were created and tested. This test method is a simple procedure, clamping/unclamping the specimens is easy to achieve and only one type of specimen is required to generate all loading conditions. Also, the correction factors were determined via two- and three-dimensional analysis and the results were compared. According to the results a modified two-dimensional finite element model was proposed and studied. Results indicated that the interlaminar cracked specimen is tougher in shear loading condition and weaker in tensile loading condition. Response of woven carbon-epoxy composite was also investigated through several criteria and the best criterion was selected. Furthermore, fracture surfaces for different mixed-mode loading conditions were studied by scanning electron microscopy (SEM).