Comparison of Numerical Methods for Fluid-Structure Interaction Simulation of Fused Deposition Modeled Nylon Components

A comparison is made between three different methods for fluid structure interaction (FSI) simulation of fused deposition modeled (FDM) nylon components having arbitrary internal cavity structures. The FSI methods studied include a simple fluid cavity (FC) model, a coupled Eulerian-Lagrangian (CEL) method, and a smoothed particle hydrodynamics (SPH) method. Model valuations are based on comparing the predicted macro compressive strengths for the simulated FDM builds with experimentally determined compressive yield strengths on actual FDM builds. Each simulation includes two Phases, where the first models the FDM build to compute thermal distortion and residual stresses. The second Phase applies the temperature distribution and state of stress from the first Phase as initial conditions, then includes an FSI simulation wherein the part undergoes quasi-static compression. It is found that the CEL and SPH methods demonstrate higher accuracy than FC, producing less than 2.5% and 1.06% errors, respectively, compared to the experiments. Considering computational demands, the results suggest SPH to be the most suitable method to capture the FSI effects. A case study illustrating generality of the approaches to a different FDM geometry is also included.