BLOCK LOADING SEQUENCE EFFECTS ON FATIGUE IN THE COPPER ALLOY CU-35-PERCENT-NI-3.5-PERCENT-CR

In the present study, experimental results are presented for monotonic tests and cyclic tests of the copper alloy Cu-35%Ni-3.5%Cr with diffe rent block loading histories, Cyclic loading with variable amplitude s hows that the lifetime of this metal depends on the sequence of loadin g. Changes from high to low amplitudes shorten the fatigue lifetime, a nd changes from low to high amplitudes extend it, compared with the th eoretical lifetime calculated according to Miner's rule. In the analys is of the fatigue block loading damage data a non-linear cumulative da mage rule is adopted. The predicted results are compared with experime ntal data. Good agreement is noted between predicted and experimental results for the analysed metal and cases of loading histories.