Contact Durability Analysis Methodology and Applications in Vehicle Powertrain Components Design

Contact stress analysis or surface fatigue life prediction is a subject frequently encountered in powertrain component designs. Examples are the design of gears, bearings, cams, and load ramps. In many cases, design evaluations rely on simple analysis, component supplier's suggestions, and prototype testing. One viable technology trend in modern engineering, however, is to use computer simulation and analysis as a design guide. It is universally acknowledged that up-front computer-aided-engineering (CAE) will reduce the product development cycle time and cost, and improve product quality. In addition, this approach provides a good platform for technology growth. Scattered examples on surface durability analytical modeling techniques are available in the literature. But, the most suitable engineering tools for routine product design support are yet to be developed. Currently, a semi-empirical approach is widely used in the industry. In this method, component SN curves are experimentally measured and used as a correspondence between loads and life cycles. Issues regarding this approach are reviewed. Possible directions for technology advancements are explored. For illustration, two examples are given for an off-highway tandem drive axle.