DAMAGE PROGRESSION OF IMPACT DAMAGED MULTI-AXIAL KNITTED CFRP LAMINATE FOR MARINE USE

摘要

This study focused to multi-axial knitted fabric which is expected as a thick and high performance reinforcement for large scale composite structures. The effects of impact damage on multi-axial knitted CFRP laminates molded by vacuum assisted resin transfer molding (VARTM) method were evaluated. Impact damage inside material was evaluated by ultrasonic scanning device and optical cross-sectional observation. Probed images obtained by both non-destructive and destructive methods were compared each other, and internal damage distribution of multi-axial knitted CFRP laminates was clarified. In additionally, residual compressive strength and fatigue property of impact damaged CFRP laminates were evaluated. From the ultrasonic C-scan images and cross-sectional photographs, three-dimensional damage distribution of impacted CFRP laminate was obtained. Also by post impact fatigue (PIF) test, damage progress behavior was observed.