Identification of young modulus profile in PVC foam core thickness using speckle inteferometry and inverse method

The aim of this paper is to investigate the mechanical properties of a PVC foam core and especially the Young modulus profile along a commercialised 50 mm beam thickness.The identification of the Young modulus gradient is realised through the uniaxial compression test of a 50 mm cube sample.The in-plane strain fields of one cube face under loading in both directions (longitudinal and transversal) are achieved using a diffuse light interferometric technique, the speckle interferometry.Next to that, a numerical model is built using finite elements code CAST3M.We choose a multilayer model in order to introduce spatial variation of the mechanical properties.The boundaries conditions are very close to those prescribed in the experimental tests.Finally, the present work shows that the non uniform profile of the Young modulus can be estimated by using a simple inverse method and the finite elements analysis to reproduce the experimental strain field.