Modeling of the Stiffness of Corrugated Cardboard Considering Material Non-linear Effect

This paper studies the application of corrugated cardboard in vibration isolators. Cardboard is known as a highly environment-friendly material. The focus of the study was on modeling of the stiffness of a cardboard or a group of cardboard (cardboard system) along the cardboard's thickness direction which is also the vibration direction. Cardboard in this study is corrugated cardboard. There are two shortcomings in modeling the stiffness of such cardboard in literature: (1) neglect of the material non-linear effect of cardboard, and (2) neglect of the effect of cardboard width even for the situation that cardboard width is greater than cardboard length. A finite element method was applied to overcome these shortcomings - particularly by adopting an orthotopic material constitutive model and using a shell element. In addition, the study also examined the effect of inaccuracy in describing the core shape on prediction of the stiffness of cardboard. The experiment was performed, which shows significant improvements in the prediction accuracy with the new finite element model.