A large-scale fatigue testing machine based on the rotating beam method in a four-point bending configuration was designed and built. With the device, high-strength metal specimens with a 32-mm gauge diameter and a 100-mm gauge length can be tested at a cyclic frequency of up to 48 Hz. In this work, particular attention was paid to evaluating the spatial and temporal uniformity of the loading within the large specimen; methods for quantitative evaluation of these effects were developed. The developed test methodology allows for the fatigue testing of specimens with size, microstructure, and surface conditions that are similar to actual machine parts.
M. Isakov, O. Rantalainen, T. Saarinen, A. Lehtovaara (2022) Large‑Scale Fatigue Testing Based on the Rotating Beam Method, Experimental Techniques (open access).