Experimental investigation of mixed-mode fracture behaviour of woven laminated composite

In this paper, the mixed-mode interlaminar fracture behaviour 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 has a simple procedure, clamping/unclamping the specimens are easy to achieve and only one type of specimen is required to generate all loading conditions. Also, finite element analysis was carried out for different loading conditions in order to determine correction factors needed for fracture toughness calculations. Interlaminar fracture toughness was determined experimentally with the modified version of the Arcan specimen under different mixed-mode loading conditions. 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. The interlaminar fracture surfaces of the carbon-epoxy composite under different mixed-mode loading conditions are examined by scanning electron microscopy (SEM).