Damage Observation and Simulation of Woven Fabric CFRP for Clarification of Damage Mechanism

Abstract

Fatigue test have been conducted on impact damaged coupons of T 300 plane woven fabric / vinylester resin. Two damaged levels were used to represent BVD(barely visible damage)and NVD(non visible damage). Fatigue tests were conducted at a frequency of 5 Hz and a load ratio of R =-1. Three levels of maximum stress were prepared. Impact damage and damage growth behavior were observed using several nondestructive evaluations such as ultrasonic C-scan and thermo elastic stress analyzer(TESA). Ultrasonic C-scan was sensitive to delamination, on the other hand, TESA was sensitive to fiber breakage. For this reason, sum of principal stress at surface were evaluated using TESA image. Moreover, from TESA image, internal damage was simulated using FEM analysis.