Stress-Stain Response of PVC Geomembrane under Uniaxial Tension Test

The mechanical property of polyvinyl chloride (PVC) geomembrane was usually expressed using engineering stress-strain response in traditional uniaxial tension test. By failing to account for deformation of specimen during the test, the deviation of true stress and strain maybe caused from the test results. In this paper, the true stress-strain response of PVC geomembrane was investigated using uniaxial tension test. The photographic analysis method was used to measure axial and lateral true strain of specimen. The Poissons ratio and true stress were also acquired based on measured true strain in the test. Then the true stress-strain relationship was obtained from the test results. By comparing with the engineering stress-strain results expressed by traditional method, it can be found that the engineering stress-strain result is unreasonable. The engineering stress-strain expression easily leads to the underestimation of the true stress.