A Novel Approach to Small Punch Fatigue Testing

Abstract

Miniaturised mechanical test approaches are now widely recognised as an established means of obtaining useful mechanical property information from limited material quantities. To date these methods have largely been adopted to characterise the creep, tensile and fracture characteristics of numerous material systems from a range of industrial applications. One method developed for miniaturised testing is the small punch test. Many international institutions and research faculties have now made a significant investment in realising the potential that small punch testing has to offer. However, limited success has been made in replicating a miniaturised test approach for determining the cyclic fatigue properties of a small punch disc due to the complex biaxial stress field that typically occurs in any small punch test. Therefore, to realise such an approach and to interpret the fatigue behaviour of small scale components, the mechanical test arrangement must clearly be of a highly bespoke nature. This paper will discuss the ongoing research and progress in developing a novel small punch fatigue testing facility at the Institute of Structural Materials in Swansea University. Several experiments have been performed on the titanium alloy Ti-6Al-4V at ambient room temperature and effort has been made to understand the complex damage mechanism.