Estimation of Component Fatigue Lives under Service Load-Time Functions Using an Advanced Transfer Methodology for the Transition from Specimen to Component Related Material Behaviour

Abstract

Due to steadily shortening product development cycles, the design and validation of new products mainly takes place in a virtual environment. The structural durability and a reliable lightweight design is the key target to be achieved during the product development process. A fatigue assessment has therefore to be included in the product design process from the very beginning. Because prototypes are usually not available during early product development stages, it is necessary to estimate the component behaviour by transferring material properties, which have been determined by fatigue tests on material specimens with standardized geometry, to the component geometry. In order to enable a reliable statement about the structural durability based on these simplified tests, different influencing factors have to be considered. Some of the major influencing factors on fatigue are the component size and geometry, the boundary conditions of the loading and the load-time function, and a possible location and load-history dependency of the material behaviour. The presented work will discuss those influences and how they can be treated by simplified approaches during the assessment of the component fatigue strength.