Impact damages and residual bending strength of CFRP composite laminates subjected to impact loading

The purpose of this study is to confirm the decreasing in residual bending strength, and the failure mechanisms experimentally when CFRP composite laminates are subjected to foreign object damage (FOD). Composite laminates used in this test are CFRP orthotropic laminated plates, which are stacked with two-interfaces [0 degrees(6)/90 degrees(6)](sym) and four-interfaces [0 degrees(3)/90 degrees(6)/0 degrees(3)](sym). When the specimen was subjected to transverse impact by a steel ball, the delamination area generated by the impact damage was observed by using the SAM(scanning acoustic microscope). Also, the fracture surfaces obtained by three-point bending test were observed by using the SEM(scanning electron microscope). Further, failure mechanisms were investigated based on the observed delamination areas and fracture surfaces.