A report presents information compiled from a search of the literature on failure modes of mechanical systems. The report was written to provide a reference base for the application of first-order reliability methods to mechanical systems in the development of a system-level design methodology. In the report, each of 20 failure modes is assigned to one of four classes: wear, corrosion, fatigue, or material degradation. A brief description of each class and mode is presented. For each mode, there is a definition, plus a description of one or more failure mechanism(s) and/or one or more mathematical model(s). The mathematical models include equations, denoted "limit-state relationships," that describe such quantities as rates of wear or corrosion as functions of physical and chemical conditions and of relevant process variables.

This work was done by Michael Kowal and Thomas Cruse of Vanderbilt University for Lewis Research Center. To obtain a copy of the report, "Compendium of Mechanical Limit-States," access the Technical Support Package (TSP) free on-line at www.techbriefs.com under the Mechanics category, or circle no. 133 on the TSP Order Card in this issue to receive a copy by mail ($5 charge).

Inquiries concerning rights for the commercial use of this invention should be addressed to

NASA Lewis Research Center
Commercial Technology Office
Attn: Tech Brief Patent Status
Mail Stop 7 - 3
21000 Brookpark Road
Cleveland
Ohio 44135.

Refer to LEW-16497.