Hybrid experimental and computational studies: combined compression‐bending fracture of edge‐cracked polypropylene specimens

Abstract

ABSTRACTA four‐camera system is employed to measure three‐dimensional (3D) displacements on both the front and back surfaces of a single‐edge‐notched polypropylene plate undergoing combined compression and out‐of‐plane bending. A methodology was developed to ensure that both systems employed a common coordinate system for defining the deformations on the front and back surfaces. Using the image pairs obtained simultaneously by both stereo‐vision systems, the full 3D displacement and strain history on both sides of the specimen are measured during the loading process by using the 3D digital image correlation (DIC) technique, including the crack path, load‐surface crack extension curve, load versus actuator displacement curve, crack front profiles and 3D displacement and strain fields. It is found that crack growth only occurs on the front side of the specimen where tensile stresses are present; there is no crack growth on the back side where compression occurs. A computational model is also established to reconstruct the failure process based on a simplified geometry model and nodal release technique. Good agreements are reached on the measured and predicted results on deformation, strain fields, load‐crack extension curves.