Effect of single and intermediate tensile overload cycles on effective stress range ratio in 6063-T6 Al-alloy

Abstract

In this paper, crack closure experiments were performed on 6063-T6 Al-alloy for various overload ratios at 8 mm crack length. On the basis of these experimental results some power laws are developed to predict minimum effective stress intensity range ratio ( U min ) and number of delay cycles ( N D ). The life of the specimen is also increased by increasing the magnitude of overload cycle. The crack closure load is increased after application of the overload and remains constant for a certain number of cycles. It then decreases to attain the stabilized constant amplitude loading crack closure value.