On the mixed mode fracture of DLP manufactured SCB specimens

The scope of this study is to investigate the mixed mode fracture of components manufactured from photo-polymerized resin using the Digital Light Processing (DLP) additive manufacturing technology.The mixed mode tests were performed on Semi Circular Bend (SCB) specimens loaded under symmetric Mode I, asymmetric mixed mode and mode II loading, respectively. The specimens manufactured via DLP have a crack introduced during the manufacturing process. Tests were performed at room temperature using a universal testing machine with three point bending grips at a constant loading speed. Four tests were carried on for each supports position. The experimental results expressed as 𝐾𝐼𝐼/𝐾𝐼c versus 𝐾𝐼/𝐾𝐼c are plotted by adopting four fracture criteria, namely the Maximum Tensile Stress (MTS), the Strain Energy Density (SED), the Maximum Energy Release Rate (𝐺𝑚ax), and the Equivalent Stress Intensity Factor (ESIF). Most of the experimental results fall in the range of fracture envelope curves.