Failure and Fracture Behavior of Brittle Polymer Foam

Abstract

Experimental study was performed to investigate the fracture behavior of relatively brittle polymer foam. A single notch bending specimen made of a PVC core cell foam A-series, A 800 and A 1200, are used for the investigation. To measure the strain around the defect section, a 2D digital image correction (DIC) technique was used. The fracture initiation toughness was calculated from the load displacement curve and a strain fields obtained from DIC technique. Furthermore a study was performed to investigate the failure behavior of foam core with sharp cracks, notch and circular hole. To reduce the size effect, the net cross-sectional areas of the specimen for all the geometries considered are kept constant. An Instron tensile loading machine was used and the tensile load was measured directly through the load cell. The full strain field around the section was measured using DIC and the data points at the interest location were extracted. The result was compared with the dog-bone tensile experiment of intact specimen. It was observed that, the net section strength for specimen with cracks, notch and circular hole is higher than that of the intact foam core.