Track 2 Session 7
1:00 to 2:00 p.m. Thursday March 27, 2008

Application Oriented Approach for the Integration of Load Impacts in Reliability Analysis and Life Time Prediction

Efficient production depends to a great extent on the reliability and availability of the machines and facilities used. As a consequence, mandatory reliability predictions are demanded from equipment manufacturers within the scope of availability guarantees and bids driven by life cycle costs. Due to the fact that task-related stress has a great influence on the failure behaviour of production facilities, a methodology is presented which allows, in a first step, a stress-related reliability analysis and prediction on component level in the early stage of development. Therefore, this methodology combines the results of a linear damage accumulation calculation which is related to cyclic stress with a two-parameter Weibull failure probability distribution based on operating stage failure data. The combined failure distribution provides information on the changes to reliability and availability under different stress levels. In the second step, field data with detailed stress collectives of the operating stage is analyzed using the generalized log-linear model in order to verify the first steps prognosis of the early stage of the development. Finally, a method is presented allowing the determination of the remaining lifetime of a component to optimize the preventive maintenance actions. By integrating more and more field data, it is possible to enhance the accuracy of the prognosis by constant learning.

Key Words: Impacts of Load, Linear Damage Accumulation, Generalized Log-Linear-Model, Weibull-Bayesian Approach