Finite Element Analysis Methodology for Additive Manufactured Tooling Components

Abstract

Fused deposition modeling (FDM) for additive manufacturing is constantly growing as an innovative process across the industry in areas of prototyping, tooling, and production parts across most manufacturing industry verticals such as Aerospace, Automotive, Agricultural, Healthcare, etc. One such application that is widely used is for tooling on the shop floor e.g. for pick-off tools, assembly fixtures etc. For tooling applications printing the solid fill component with +45/- 45 raster is common practice. There is a requirement for finite element analysis to validate the strength of 3D printed components for some specific applications in tooling, but due to the anisotropic behavior of 3D printed parts and the unavailability of all mechanical properties FE analysis of 3D printed parts is sometimes challenging. Advance approaches like multiscale modeling approach requires specialized & costly analytical tools. So, to understand the behavior of additively manufactured parts the team has conducted a few tests and compared the results. In this work, solid-filled dog-bone tensile test and three-point bending test specimens were printed with +45/-45 raster orientation and tested in the lab. Tensile test specimens were built with flat, on-edge, and up-right orientations and tested to determine the directional properties of young’s modulus. Using mechanical properties from the tension test 3 points bending test is simulated in FE software- ANSYS. The FE modeling was done in two ways, in first model orthotropic properties were assigned to the specimen, and for second model isotropic properties were assigned. For isotropic modeling least value of young’s modulus is used. Simulation results of three-point bending test shows that in the linear region of force-deflection curve, deformation values from FE model with both orthotropic and isotropic modeling are in good agreement with the experimental results. Also, the difference in stress results between isotropic and orthotropic FE model is almost negligible. To support this observation, study is performed for various conditions. The specimens were printed with ABS material on Ultimaker® and ASA material on Stratasys® Fortus 360mc™ machine with T12, T16 and T20 nozzle settings. Study shows, for tooling applications if the 3D printed solid-filled components are designed with a certain factor of safety then validating its strength with isotropic material properties will give acceptable results. The advantage of this approach is getting the isotropic mechanical properties is easy and modeling with FE modeling will be simple.