Experimental and FEA analysis of flexural properties of 3D printed parts

Abstract

An emerging method for creating difficult structures within minimal time is additive manufacturing. In this method, a three-dimensional object is produced by depositing a material layer by layer. Each successive layer bonds to the preceding layer of melted or partially melted material. This study aims to examine the effect of different infill patterns and infill percentages on the flexural strength of specimens fabricated using Fused Deposition Modelling (FDM). The material used for specimen fabrication is Acrylonitrile butadiene styrene (ABS) which provides a high-quality surface finish and dimensional stability. The infill patterns selected for this study are triangular and rectangular in the combination of 50 % and 70 % infill density percentages. The tensile test of ABS specimens with a 100 % infill density is done as per the ASTM D638 standard to obtain material properties and is used in FEA analysis. The specimen of the flexural test has been modeled and tested using the ASTM D790 standard. Experimentally maximum strength observed is 30.58 MPa in a triangular pattern specimen with 70 % infill density and a minimum of 14.53 MPa in a 50% infill density rectangular specimen. Further FEA analysis is done in Ansys software to examine the flexural strength of infill pattern specimens. The experimental and FEA results show that the 50 % and 70 % infill density specimen with a triangular pattern has the highest flexural strength than the rectangular pattern. In the case of 50 % infill density, experimentally obtained flexural stress values for the triangular and rectangular patterns are 20.98 MPa and 14.53 MPa respectively. The same values - with FEA analysis are 28.55 MPa and 22.88 MPa. In the case of 70 % infill density, experimentally obtained flexural stress values for the triangular and rectangular patterns are 30.58 MPa and 24.73 MPa respectively. The same values - with FEA analysis are 38.82 MPa and 33.15 MPa. Also, the results obtained from FEA were validated with the experimental results.