Crack growth in PMMA with a very little content of short glass fiber- observation of crack opening by optical interferometry
Kitagawa Masayoshi; Kai Akira; Koyama Nobuji
Abstract:In order to investigate the effect of short glass fiber on crack growth, DCB samples were machined from injection-molded PMMA plates with a very little content of short glass fibers and the crack tip in the sample was observed by means of optical interferometry. It was shown that (1) the interference fringes were distorted around the fiber crossing the crack planes over the region 2 - 3 times larger than the fiber diameter and (2) the fiber depressed the crack opening due to bridging between the crack planes, lessened the craze region in front of the crack and reduced the crack growth rate leaving the arrest line on the fracture surface. Key Words:crack growth, PMMA, short glass fiber, optical interference, bridging, crack opening