Fracture toughness of high density polyethylene: Fatigue pre-cracking versus femtolaser, razor sharpening and broaching

This work analyzes the fracture toughness under LEFM and EPFM conditions of high density polyethylene specimens sharpened via contact procedures such as razor pressing and broaching and non-contact procedures such as femtolaser and fatigue. The fatigue notch sharpening was accomplished following the guidelines for fatigue pre-cracking in metals. Under LEFM conditions, there was no influence of the notch sharpening technique on the fracture toughness but under EPFM conditions, the fracture toughness values of the fatigue sharpened specimens were the smallest. The analysis of the crack front of the non-tested specimens after sharpening allowed the explanation of these results.