The Elasto-plastic Analysis of Polymers Subject to Traction and Compression Using Advanced Discretization Techniques

Materials such as thermoplastics often have different behaviors when subjected to traction and compression. In those cases, yield criterions for nonlinear behavior need to be appropriately selected. In this work, a thermoplastic for a particular additive manufacturing process-the fused filament fabrication (FFF)-is investigated. Traction and compression tests are performed using two numerical tools and two variations of the Newton-Raphson method for the elasto-plastic incremental-iterative process. The stress-strain curves are compared with experimental data provided in the literature. The numerical tools used are the Finite Element Method (FEM) and the Radial Point Interpolation Method (RPIM), which is a meshless method [1]. In order to discretize the problem domain, meshless methods only require an unstructured nodal distribution. The numerical integration of the Galerkin weak form is performed using a background integration mesh and the nodal connectivity is enforced by the overlap of influence-domains defined in each integration point. In the end, a comparison study is performed between the results obtained using the meshless method and the finite element method.