Mechanical properties of PVC geomembrane based on non-contact measurement

Abstract

The mechanical properties of polyvinyl chloride (PVC) geomembrane (GM), particularly its elastic modulus, are of the utmost importance in engineering design and evaluation of performance. The existing test methods make it difficult to provide an accurate elastic modulus of PVC GM. This research presents the establishment of an improved method for analysing the true stress–strain by non-contact measurement technology to determine the elastic modulus. Digital image correlation (DIC) was used to measure the axial and transverse strain, and it was found to give measurements of strain with a high degree of accuracy. The variation of Poisson's ratio is discussed and the true cross-sectional area is determined, allowing the true stress to be calculated theoretically. In accordance with the true stress–strain curve, the elastic modulus and linear range are established, which can provide designers with the tools to evaluate the true performance of GM and help them to select anti-seepage materials in design.