Determination of local stresses and strains within the notch strain approach: The efficient and accurate calculation of notch root strains using finite element analysis

Abstract

For the service life estimation of metallic components under cyclic loading according to strain‐based approaches, a simulation of the elastic‐plastic stress–strain path at the point of interest is necessary. An efficient method for determining this stress–strain path is the use of the load–notch-strain curve, as this is also implemented within the FKM guideline nonlinear. The load–notch‐strain curve describes the relationship between the load on the component and the local elastic‐plastic strain. On the one hand, this can be estimated from loads or theoretical elastic stresses by using notch root approximations. On the other hand, this can be determined in a finite element analysis based on the elastic‐plastic material behaviour. This contribution describes how this latter option is carried out in general and how it can be optimised in such a way that the FEA requires significantly less calculation time. To show the benefit of this optimisation, a comparative calculation on an ex-emplary geometry is carried out.