On the choice of the testing base for materials and components for fatigue resistance

Abstract

Fatigue resistance testing allows solving many tasks related to the design, manufacturing, and operation of machine parts. Their relevance is due to the fact that they can achieve high accuracy in assessing the fatigue strength of components. Moreover, they may be the only way to address certain specialized tasks. For example, they are indispensable for determining the fatigue resistance characteristics of new materials and alloys, conducting technical expertise of parts that failed during operation, and so on. An important factor in conducting fatigue resistance tests is the choice of the testing base, which determines their duration and effectiveness. When choosing it, the strength characteristics of materials are primarily taken into account, also considering the recommendations of the standard. Additionally, it is necessary to consider the type of fatigue curve equation, which determines the relationship between the testing base and the fracture point of this curve. The paper analyzes the change in the position of the fatigue curve fracture point depending on the endurance limit for three equations (power, exponential, and Weibull). Correlation relationships between the parameters of these equations and the endurance limit were used for calculations. The obtained dependencies lead to the disappointing conclusion that the nature of the findings is contradictory and influenced by the choice of the fatigue curve model.