Research On Cushion Properties Of Film And Mechanical Behavior Of Air Cushion

The rapid development of the commodity economy, especially the popular onlineshopping, has put forward higher requirements for cushion packaging. An air cushionis made of polymer films filled with gases. It is a kind of environmental cushionpackaging material which has excellent cushioning properties. It is mainly used inelectronic products, fragile products as inner protective packaging. Experiments andfinite element analysis (FEA) are hired to study the mechanical behavior of thepolymer film and performance of the air cushion materials, which lay the foundationfor the FEA methods of cushion packaging design.Taking into account the highly nonlinear elasticity of the film material, based oncontinuum mechanics, a hyperelastic constitutive model is proposed for the film. Auser defined subroutine UHYPER is developed to transfer the hyperelasticconstitutive model into the general purposed nonlinear finite element analysissoftware ABAQUS. Simulation of static compression of the air cushion is carried outto compare with experiments. The results show that the proposed constitutive modelcan well describe the mechanical behaviors of the film in static compression.The effects of inflation pressure on cushion properties of air cushion areanalyzed by finite element simulation. The results show that the larger the inflationpressure, the larger the carrying capacity. Besides, within a certain range, the smallerthe inflation pressure, the smaller the cushion coefficient and then the better thecushion performance.Considering the actual working conditions of air cushion, dynamic compressionexperiments are conducted to explore the effects of inflation pressure on the air cushioning properties under the same impact energy. The proposed hyperelastic modelis extended to a visco-hyperelastic one taking into account the influence of strain rateon the mechanical behavior of the air cushion film. By fitting the experimental data,the parameters in the model are obtained, and the model is successfully applied topredict the mechanical behavior of film at strain rate of0.064/s.