Static and fatigue behavior in presence of notches for polyamide 12 (PA12) additively manufactured via Multi Jet FusionTM process

Static, fatigue and notch sensitivity tests were performed on Multi Jet FusionTM (MJF) Polyamide 12 (PA12) specimens in unnotched conditions or with blunt/sharp notches. Stress concentration factors, and potential applicability of theory of critical distances (TCD) were investigated. Fracture surfaces were comparatively analyzed for quasi-static, fatigue and cryogenic failures. Stress-Life curves were determined and MJF-PA12 showed static and fatigue properties comparable to conventional PA12. The blunt notch had limited impact on fatigue strength, with failure onsetting from internal defects. The sharp notch showed low fatigue notch sensitivity but reduced static strength and fatigue life, with failure onsetting from notch tip.

Automated summary

Static, fatigue and notch sensitivity tests were performed on MJF-PA12 specimens, and fracture surfaces were comparatively analyzed. The results showed that MJF-PA12 exhibited static and fatigue properties comparable to conventional PA12. The sharp notch reduced static strength and fatigue life, while the blunt notch had limited impact on fatigue strength.