Gearbox Load and Life Simulation Software Navy SBIR FY2009.1 Sol No.: Navy SBIR FY2009.1 Topic No.: N091-017 Topic Title: Gearbox Load and Life Simulation Software Proposal No.: N091-017-0548 Firm: Sentient Corporation 850 Energy Drive Suite 307 Idaho Falls, Idaho 83401 Contact: Nate Bolander Phone: (208) 522-8560 Web Site: www.sentientscience.com Abstract: Gear tooth surface fatigue (pitting) is common precursor failure mode that leads to excessive gear vibration, liberation of debris particles that damage ancillary components (e.g. bearings), and serves as crack initiation sites that lead to eventual catastrophic tooth failure. Current gearbox life estimation techniques commonly underplay the significance of gear tooth surface fatigue due to the complexity of the phenomenon involved. In this Phase I program, technologies necessary for rigorous inclusion of surface fatigue failure will be developed to provide a better estimation of gearbox life for a given set of experienced (past) and anticipated (future) mission profiles. Finite element analysis will be coupled with a detailed mixed-elastohydrodynamic lubrication model and continuum damage mechanics approaches to predict damage accumulation rates in the material microstructure. Estimations of dynamic loading will be obtained through lumped-parameter analysis of the gearbox system. The completed software will provide analysts with a tool to predict the current damage state in helicopter gearboxes and evaluate remaining useful life for anticipated mission profiles. Benefits: There is enormous commercial potential for design software that fills the gaps in current understanding of gearbox life. Traditionally, due to a lack of fundamental understanding and methods to incorporate gear teeth interaction, gearboxes are simply `overdesigned' by incorporating large safety factors. However, this approach becomes problematic in applications where constrained weight and space are desirable (e.g. aerospace, wind turbines, etc.). The proposed software provides a more rigorous analysis of gear tooth life based on a fundamental understanding of the tribological phenomena at the gear mesh. This software will provide a means of optimizing gearbox designs for weight and size, as well as improved estimations of gearbox life under variable loading. This latter factor is a proving to be of significant interest in both commercial and military applications, as it is an enabling technology for condition-based maintenance strategies. The algorithms developed in this proposal are generally applicable over a wide range of gear geometries, and therefore would find use in a number of different industrial applications (e.g. aerospace, automotive, power generation). Return