Mixed Mode Fracture Behavior of PMMA by Bend Test

摘要

Using bend specimen, mixed mode fracture test on PMMA was conducted not only to investigate the effect of sear stress on crack growth path but also to evaluate relevant parameters governing crack initiation and propagation behavior. A microscopic examination on the fracture surface shows an obvious transition from initial stable fibrous fracture to flat mirror-like unstable fracture when the shearing stress increases. The crack growth path is simulated by Gmax criterion as long as stable crack propagation takes place. The crack propagation behavior under mixed mode loading is discussed from the viewpoint of energy release rate.