Overview of the Development of a Numerical Model for an Inflatable Paper Dunnage Bag

摘要

This paper presents the development of a numerical model for an inflatable paper dunnage bag. Dunnage bags are used to fill the voids between cargo, securing the cargo in place. The presented numerical model is developed as a design tool for investigating trends associated with new or modified bags. Modelling considerations are outlined, including the effects of material, geometry and boundary condition non-linearity. An emphasis is placed on the material properties of paper and the material model chosen for this model is discussed. First, the development of a stable generic model is described in detail. The effects of the timescale factor, the load application, the analysis time, global damping, mesh refinement, the Poisson ratio and mass scaling are investigated. Next, the development of a representative model follows, where the process of including the inflation valve, glued seam lines, void constraint size and material model are discussed. Physical testing was performed, and the results were used to validate the numerical model. The validation results indicate that the presented numerical model is accurate enough to be used as a design tool for investigating trends associated with new or modified paper dunnage bags. Numerical modelling of the inflation and static testing of paper dunnage bags are non-trivial operations and have, to the best knowledge of the authors, not been reported in the literature. A secondary goal of this paper is to provide a guideline for future designers that are interested in numerical modelling of paper dunnage bags.