Methods for durability diagram plotting

Proceeding from the processing of test results a possibility has been established for a simple approximation of the relationship between durability N and the characteristic of loading cycle (cycle amplitude, mean value of the cycle amplitude, assymetry coefficient). Numeric values are given for the parameters of the approximating function for steels 30KhGSNA, VNS-2 and titanic alloy VT20. The tests have been carried out on a low-frequency pulsator with a loading frequency of 0.17 Hz. For the test range of durability (N approximately 103 - 105 cycles) and the assymetry coefficient the approximation of the test data is considered to be acceptable to a sufficient extent