Fatigue Modeling of a Powder Metallurgy Main Bearing Cap

Hammi, Y., Stone, T.W., Allison, P., & Horstemeyer, M. (2010). Fatigue Modeling of a Powder Metallurgy Main Bearing Cap. 2010 SIMULIA Customer Conference. Providence, RI: 3DS SIMULIA.

Developing the ability to predict density distribution, monotonic plasticity, damage and the cyclic damage progression is imperative for the design of Powder Metallurgy (PM) components that will experience overloads during in-service life due to impacts, rough ground, and crash environments. In this paper, mathematical-based models for PM manufacturing process are developed, validated and implemented in user material subroutines VUMAT and UMAT to model the compaction and sintering processes. The material history is initially captured and carried throughout the compaction and sintering processes in order to predict the density distribution. Knowing the density distribution, mechanical properties are mapped in the PM sintered part using tension, compression, and torsion mechanical tests performed on samples at different densities, temperatures and strain rates. A finite element analysis of an experimental fatigue fixture that reproduces similar loading conditions than those of in-service life conditions is performed. Using a Multi-Stage Fatigue (MSF) model implemented in Abaqus, the fatigue life is evaluated on a PM automotive component, the main bearing cap (MBC), and results are compared to experimental fatigue tests.