Optimal test planning for High Cycle Fatigue limit testing

Abstract

In High Cycle Fatigue (HCF) limit testing the fatigue limit of a mechanical component is determined by applying cyclical stress of a certain amplitude and noting whether the component breaks or not. Since testing is time consuming and expensive, the number of test samples should be kept to a minimum. A common protocol for finding the fatigue limit distribution is the staircase method, in which the testing amplitude is decreased or increased with a fixed step depending on whether the component in the previous test did break or not. We have developed and implemented an alternative protocol, based on Bayesian experimental design, in which the amplitude of each test is selected to maximize the expected information gain of the test. Simulations show that with the proposed method the number of required test samples is significantly decreased as compared to with the staircase method.