Influence of stress triaxiality and strain rate on stress-strain behaviour and dilation of mineral-filled PVC

Abstract

The influence of stress triaxiality and strain rate on the tensile behaviour of mineral-filled polyvinyl chloride (PVC) is investigated in this paper. Axisymmetric notched tensile specimens with notch radius equal to 20 mm, 5 mm and 2 mm were tested at three nominal strain rates of 0.0001s−1, 0.001s−1 and 0.01s−1. Surface deformations were measured by digital image correlation and contour tracking, employing two orthogonal cameras, whereas infrared thermography was used to measure self-heating. The yield strength of the material was found to be strain rate and pressure dependent. The volume change was estimated from the stretch field in the notch region of the specimens and found to depend on both stress triaxiality and strain rate. A marked increase of temperature was measured at the highest strain rate.