Effect of Laminate Configuration on the Damage Progress and Strain Concentration in CFRP Laminates with an Open Hole

Abstract

Quasi-static tension tests were conducted on CFRP laminates with an open hole to clarify the effect of lamination configuration on both the behavior of microscopic damages and strain concentration factor at the edge of the open hole. Laminate configurations are angle-ply［±θ]_s(θ＝30,45,60゜) and quasi-isotropic［±30/90]_s and ［±45/90]_s. An open hole was introduced at the center of the specimen. A soft X-ray radiography was used to detect the internal microscopic damage progress. Damage progress was observed in［±30]_s,［±30/90]_s and［±45/90]_s laminate. In the failure process of［±45]_s and［±60]_s laminates, no damage was observed until the specimen final fracture. These laminates failed in a catastrophic manner. Moiré interferometry was applied to measure the microscopic deformation. The observation with a moiré interferometer revealed the whole-field strain distribution on the specimen surface. The effect of laminate configuration on strain concentration factor was clarified experimentally.