Theory of critical distances and finite fatigue lifetime of notched additively manufactured polylactide

In 1999 Prof. David Taylor proposed a novel material length-based approach specifically devised to estimate notch fatigue limits of metallic materials [1]. Nowadays, this very successful fatigue design technique is known as the Theory of Critical Distances (TCD). In 2004 we were awarded an IRCSET Post-Doc fellowship to reformulate (under the supervision of Prof. David Taylor) the TCD to make it suitable for estimating finite fatigue lifetime of notched metallic components [2]. Two decades later, to celebrate Prof. David Taylor’s outstanding research achievements, the present paper reviews the work we supervised over the last 6 years [3-6] in order to extend the use of the TCD to the fatigue assessment of notched 3D-printed polylactide (PLA).