Failure of SLS polyamide 12 notched samples at high loading rates

Abstract

The failure load of polymeric notched samples is necessarily affected by the loading rate due to the extreme influence of strain rate on the mechanical behaviour of polymers, and consequently, the characteristic stress in the Theory of Critical Distances (TDC) should be influenced by the loading rates. The objective of this work is to study the effect of strain rate on the parameters determined by the TDC using notched samples in additive manufactured polyamide PA12. To this end, tensile specimens have been prepared by Selective Laser Sintering (SLS) with different notch radius. Experiments in a wide range of strain rate have been carried out, from those representatives to static conditions in electromechanical machines to Hopkinson bar tests at very high strain rates.