Experimental Investigation of Dynamic Fracture Behaviors of Polymethyl Methacrylate

摘要

Dynamic fracture of polymers plays a vital role in engineering applications. Dynamic fracture behaviors of polymethyl methacrylate were studied using the optical method of caustics. Semi-circular bending specimens were chosen for mixed-mode fracture and crack interaction analysis. The crack initiation, crack propagation, stress intensity factor, and fracture toughness were obtained by analyzing the specke patterns captured during dynamic loading by high-speed imaging techniques. The crack interactions of two symmetric and asymmetric cracks and the influence of damage, including the presence of holes andmicrocracks on or near the crack path, are discussed. The results show that two cracks on a specimen compete and interact with each other, and lead to the final fracture mode of the specimens. Holes and microcracks on or near the crack path influence the crack path and the crack propagation velocity. The results obtained in this paper could be extended to brittle fracture analysis of materials with multiple cracks or inclusions.