Cyclic stress-strain and strain-life properties of aerospace metallic materials

Abstract

IHS ESDU decided to approach a number of organisations in order to compile a reference source of cyclic stress-strain and strain-life properties for the benefit of the wider aerospace industry. Work began in 2006 on the collection and collation of the raw data points for commonly-used aerospace metallic materials. Beside the data available in the literature and other readily-accessible sources, efforts were made to encourage organisations with their own data to contribute to a database from which they would subsequently benefit. Considerable support and enthusiasm were expressed for the project and generous donations of data were received from a number of organisations. These data were combined with those gathered from public domain sources and those considered to be the most robust were retained. Cyclic stress-strain curves fitted using the Ramberg-Osgood equation were found to correlate well with the test data. The Coffin-Manson strain-life model was generally less successful but curves are provided due to their widespread use. The resulting set of cyclic stress-strain and strain-life properties of commonly-used aerospace metallic materials permits a wider appreciation of material fatigue behaviour not previously available. The results are to be published in forthcoming IHS ESDU Data Item Number 11003. Analysis of specimen geometries led to some simple design recommendations that may be useful to those considering future strain-controlled testing.