Abstract:

ESDU 11003 presents cyclic stress-strain and strain-life data for a number of commonly used aerospace metallic materials. It has been compiled using data from both published sources and donated unpublished industry sources. This has allowed many data sets for similar materials to be compared side-by-side for the first time and an appreciation of the amount of scatter to be gained. Lines have been drawn through the data based on a combination of traditional techniques and engineering judgement.

The data are derived from testing of largely un-notched specimens whose behaviour is generally equated to that at the root of a notch. Use of the data to simulate the fatigue behaviour of structures invariably requires the incorporation of all effects on fatigue performance. These may include, but may not be limited to, those due to: geometry, surface condition, environment, frequency and fretting. In addition appropriate account must be taken of mean stress, residual stress and variable amplitude loading.

The development of design data to account for all effects on fatigue performance in notched structures is a key part of the design process. This often requires the tuning of fatigue predictions made using the basic test data to the results of tests made on representative notched structure.

To assist in this, the known test conditions are tabulated in the Data Item. In addition, all of the plotted test points are supplied to enable the user to focus on individual data sets, should they be considered more relevant than the combined data for a particular material.