Formation of the science of fatigue of metals.: Part 1.: 1825-1870

We describe the first stage (1830-1870) of formation of the science of cyclic fatigue of metals closely related to the events of failures of railway transport. In the 1830s, French engineers (J.B. Ponce let, A. Morin, and others) described the phenomenon fatigue. The scientific research into this field was originated in the 1840s in England (W.J. Rankine, H. James, W. Fairbairn, J.E. MacConnel, et al.). However, the first fundamental investigations were carried out in Germany by A. Wohler. He developed a method and means (machines and devices) for fatigue testing of car axles and specimens and introduced the notions of fatigue limit and the number of cycles to failure as the main characteristics of the fatigue resistance of the metal. As a result of systematic investigations, he accumulated a vast amount of data on the fatigue behavior of metals depending on the loading mode (bending, twisting, or tension), stress ratio, notches, etc.