On the optimal choice of experiments for determination of parameters in multiaxial HCF-criteria

• Optimal test strategies for multiaxial fatigue characterization.
• Different types of scatter are included in the investigation.
• Performing few types of test is the most beneficial test strategy.
• Scatter in fatigue limit contributes most to scatter in the material parameters.

Material parameters in multiaxial HCF-criteria must be estimated from experiments, which always are affected by scatter from several sources. A higher number of tests provides a more reliable parameter estimation, but the cost for the testing increases. In this paper, by starting from a known fatigue limit distribution for the titanium alloy Ti-6-4, test series are simulated according to different predefined test strategies. In Monte Carlo simulations, scatter in the material properties and in specimen alignment in the testing machine is taken into account. Based on the results obtained from the simulations, it is determined which one of the defined strategies that is most beneficial for HCF-criteria material parameter estimation, and also how many tests that should be performed in order to maximize the benefit of the information obtained from the fatigue testing.