Mean Stress Sensitivity
Mean stress sensitivity is a measure of the influence of a constant static prestress on the allowable cyclic stress of a material. It is used to correct Wöhler curves for asymmetric cycles.
Physical-Chemical Mechanism of Action
Mean stress sensitivity describes how a constant static preload affects the permissible fluctuating load of a material. In unsymmetrical loading cycles, this preload can lead to increased stress.
Metallurgical Relevance & Risks in Welding
High mean stress sensitivity means that a small static preload strongly affects the permissible fluctuating load. This can lead to reduced life and the initiation of cracks, especially under high loads.
Workshop Practice & Instructions
To account for mean stress sensitivity, Wöhler curves should be corrected accordingly for unsymmetrical cycles. This can be achieved by considering the static preload. Under high loads, it is important to ensure careful monitoring and control of stress constants.