Influence of LCF Loadings on HCF Crack Growth

摘要

This report results from a contract tasking University of Portsmouth as follows: The contractor will conduct an experimental program to examine the effects of low cycle fatigue (LCF) loading on high cycle fatigue (HCF) crack growth. The project will also extend and refine the current model of combined LCF/HCF fatigue crack growth. The project will use Ti-6Al-4V alloy and corner notched specimens for the combined LCF/HCF testing. The program will focus on three main aspects of the problem: (1) Investigate the effect of LCF overloads on larger number of blocks of HCF cycles than previously used, e.g. 10,000/block versus 1,000/block. (2) Introduce overloads into simple spectrum loading. (3) Extend previous modeling of combined cycle fatigue crack growth based on the results of this project.