Determination of mechanical properties of very thin 3D-printed specimens for numerical analysis of tensile strength and fracture toughness

This research deals with the influence of thickness on the mechanical properties of polyamide (PA12) samples produced by the SLS 3D technology. Experiments included fracture toughness and simple tensile tests on samples with thicknesses ranging from 0.50 mm to 2.00 mm. The experiment revealed that the thickness of the specimen significantly affected the tensile strength and Young’s modulus. The measured tensile strength (22–34 MPa) was notably lower than the 41 MPa reported by the manufacturer. As a result, a numerical analysis using ATENA software showed substantial discrepancies between the FEA predictions and the experimental data. This led to a modification of the material model and the determination of the effective Young’s modulus fit to thin polyamide samples, which improved the agreement of the numerical and experimental data.