A Visco-Hyperelastic Constitutive Model for Multilayer Polymer Membranes and its Application in Packaging Air Cushion

Air cushion is an important packaging material with admirable cushion property in protecting articles from damage. Polymer membrane in air cushion renders a highly nonlinear elastic and rate dependent mechanical behavior in experimental tensile test. A visco-hyperelastic constitutive model for a polymer membrane of an air cushion is developed by additively decomposing its mechanical response into a hyperelastic portion and a viscoelastic portion. Material parameters are consecutively obtained by matching experimental data of static and dynamic uni-axial tensile tests of the membrane, respectively. Compression test of a single air column of the air cushion is conducted as a means of validation on the proposed constitutive model. By comparing simulation results with experimental data, it is shown that the proposed visco-hyperelastic model can properly characterize the mechanical behavior of the air cushion packaging material. The model can be applied to evaluate cushion performance of air cushions and their optimum design.