Numerical evaluation of the infill pattern upon mechanical proprieties of 3D printed materials

The effect of the structure that is printed inside an object, known as infill pattern, on mechanical proprieties of ABS specimens was investigated in this paper. Numerous studies demonstrated that parts created with fused deposition molding (FDM) technology present inferior mechanical properties due to additional porosity and anisotropy caused by the nature of the manufacturing process. In this regard the influence of printing parameters may be analyzed for correct evaluation of mechanical behavior and material constants. The methodology proposed in this paper consists of a numerical simulation of the fused deposition moulding 3D printed specimen, identification of the real cross-sectional area and evaluation of the strain-stress curves of the materials. There are several infill pattern geometries, each with benefits and compromises between material usage, printing time or mechanical strength of the obtained part. The current paper analysed specimens with 100% density (infill rate) but having different infill patterns: grid 0°-90° and ±45°, triangular 60°, fast honeycomb, full honeycomb and wiggle. The results are showing the dependence of the specimen's E modulus with the infill pattern and comparison of the strain-stress curves drawn with full cross-section and numerically calculated ones.