Tensile failure prediction for cellular lattice structure fabricated by material extrusion using cohesive zone model
Rosen, David W.
Date of Issue2018
Proceedings of the 3rd International Conference on Progress in Additive Manufacturing (Pro-AM 2018)
School of Mechanical and Aerospace Engineering
Singapore Centre for 3D Printing
In material extrusion, the geometrical approximation process introduces defects such as voids and gaps in the build plane as well as along the building direction. These serve as crack initiation sites and increase possibility of fracture by crack propagation. As a result, structural members under tensile loading in lattice structures tend to fail at significantly lower stresses than strengths that are estimated only based on elastic or plastic failure criteria. In this paper, we present a failure prediction approach for material extruded cellular lattice structures under tensile loading. The approach is based on a cohesive zone model (CZM) and assesses two failure criteria: elastic failure and fracture. We constructed as-fabricated voxel models for lattice structures and inserted cohesive zone element at interfaces between layers. The failure strength was estimated using the voxel models and are compared with test results.
Cellular Lattice Structure
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