Defect tolerant design of automotive components

The problem of the fatigue strength estimation of materials or components containing natural defects, inclusions or inhomogeneities is of great importance from both a scientifical or industrial point of view. An attracting feature of the fatigue strength estimation of components containing defects is undoubtedly the possibility to adopt a new design philosophy and to forecast the fatigue strength of a 'fleet' of components that contain various sorts of defects due to the manufacturing process. In this paper we discussed the application of this methodology to the defect tolerant design of automotive components. The components under examination were engine conrods either made of cast iron or made by hot forging in carbon steel. The experiments carried out allowed us to discuss the application of Murakami-Endo's model to industrial components, dealing with variability of material properties and microstructure, residual stresses, methods for the research of defects. Attention was eventually focussed on the statistical analysis of defects in order to obtain reliable estimates of maximum defects. (C) 1997 Elsevier Science Ltd. All rights reserved.