RATIONALIZATION OF MATERIAL PROPERTIES FOR STRUCTURAL AND DURABILITY MODELING OF CASTINGS

摘要

Finite element analysis models crucially depend on mechanical properties in constituitive equations for stress-strain fields and fatigue damage. Choosing appropriate values of these properties is most difficult as knowledge of properties must be inferred from prior testing, which may not represent the future. Part geometry and availability often limit sampling. Billets and coupons are more conveniently sized, but measured properties must correlate back to parts. Properties vary due to process- and alloy-sensitive gradients in microstructure. Moreover, properties are random variables exhibiting mean and standard deviation estimated with significant uncertainty. This paper will discuss these and other issues in determining mechanical properties and in selection of values of mechanical properties for structural and durability analysis of cast automotive engine components.