The effects of random loading and block loading on fatigue life
Whittemore, Alison Frances
Merwin, John E.
Master of Science
A study of the fatigue failure of welded T-sections under cyclic loading is presented in this thesis. Fatigue is a problem of great concern to industry today, especially in the area of offshore platform design and analysis. The goal of this thesis is to examine one specific area of fatigue failure and provide some insight into the basic concepts of fatigue. The first half of this study deals with the application of constant amplitude loading to a large number of welded T-sections. Failure points were carefully recorded and from this data a curve was generated for expected life of a specimen. This curve was then used to predict the failure for all subsequent tests. The second section of this study is a review of the Palmgren-Miner rule of damage accumulation, which has been used for many years for prediction of fatigue damage and failure. Tests were run under several different types of loading, including random loading and block loading, and experimental results were compared to those predicted by the rule.