Fracture assessment of inclined double keyhole notches in polylactic acid specimens fabricated by fused deposition modeling and traditional method

The fracture behavior of specimens made of polylactic acid and weakened by inclined double keyhole notches is investigated by both experimental and numerical methods. The test specimens are fabricated by two different methods; fused deposition modeling and traditional methods. The mechanical behavior of specimens was investigated under mixed-mode loading with different notch inclination angles, various notch tip radius, and multiple raster angles. An experimental program was performed, and 72 new experimental data were provided. A fracture criterion based on the strain energy density is used to assess the critical fracture loads of the tested specimens. Good agreement is found between experimental and numerical data. The results showed that increasing the notch inclination angle and notch tip radius led to a decrease in the fracture load of the specimens. Also, fracture loads of the classical specimens are higher than the 3D-printed specimens. In the 3D-printed specimens, fracture loads for the samples with raster angles of 0 degrees, 45 degrees, and 90 degrees have the highest value, respectively.HighlightsFracture assessment of polylactic acid specimensSpecimens were weakened by using an eccentric inclined double keyhole notchSpecimens manufactured by fused deposition modeling and traditional methodInvestigation of different notch inclination angles and notch tip radiusEvaluation of specimens using experimental and numerical analysis methods The polylactic acid specimens weakened by inclined double keyhole notches are fabricated by 3D printer and hot-press machine, and the fracture behavior of specimens is investigated by both experimental and numerical methods.image