A New Procedure to Evaluate Stress Integrals

With the help of the statistical size scale effects, it is possible to transform characteristic values of fatigue life to structural parts having different shape and size. Stress integrals are used to define the required size of the highly stressed parts. If the stress integral is defined by using a FE-program, special FE-processors are required to assign the discreet points of the stress to a surface or a volume. These FE-postprocessors are limited in their capacities by the FE program used, by the choice of the element and by the integration field (surface or volume). In this article a method ("SPIEL") is presented which enables the attribution of the surface or volume to a given loading thanks to an appropriate choice of unit cases. With the couples of values thus obtained it is possible to apply the numerical integration. The method presented is not fixed to any specific FE-programs.