scope:

ESDU 85031 provides R-curves for several aluminium, steel and titanium aerospace sheet materials in SI and British (lbf, in) units on transparencies for overlaying on plots of stress intensity factor against crack length appropriate to the user's structure (matching blank grids are provided to draw those curves). The curves are indexed by alloy specification, details of which are given together with relevant test conditions. A full description is included of the resistance curve concept, its application, advantages and limitations. The use of data determined from wide panel specimens is discussed. Two fully worked examples illustrate the use of the data to determine the onset of fast fracture. Two databases for each of the material types contain the tabulated R-curve coordinates in SI and British units. A program (ESDUpac A8531) is provided on the same disc in the software volume in Fortran and also compiled to run within ESDUview, a user-friendly shell that prompts on-screen for input data and runs under MS DOS. It will interrogate the databases, and output the coordinates of the R-curve for the chosen material. The input to and the output from the program are illustrated in a worked example. As new data become available, they are revised and added; the issue date given here does not therefore reflect the age of the data.