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Numerous test data have been generated in many testing institutions over the years and the historical information from previous similar designs and operating conditions can shed light on the current and future designs since they would share some common features when the changes are not drastic. To effectively utilize the historical information for current and future designs, two steps are necessary: (1) finding an approach to consistently correlate the test data; (2) utilizing Bayesian statistics, which can provide a rigorous mathematical tool for extracting useful information from the historical data. In this paper, a procedure for test sample size reduction is proposed based on historical fatigue S-N test data and Bayesian statistics. First, the statistical information is extracted from a large amount of fatigue test data collected over the years.

Driven by diesel engine emission regulation, more emission aftertretment products have been under development by Tenneco to address the Particular Matter (PM) and NOx reduction needs. The T.R.U.E. (Thermal Regeneration Unit for Exhaust) Clean active thermal management system is one of the examples to reduce PM. The system is designed to increase exhaust temperatures for DPF (Diesel Particulate Filter) regeneration. This product is exposed to high temperature and high oxidation. Therefore, thermal fatigue, creep, oxidation and the interaction become critical mechanism to be considered for its durability. One of the key challenges to validate this product is to find a way of accelerated testing for thermal, creep, and oxidation as well as for vibration. In this paper, accelerated durability test strategy for high temperature device like T.R.U.E Clean is addressed.

Creep, fatigue, oxidation, or their combinations are usually the fundamental underlying material degradation and failure mechanisms in advanced engines, manifolds, thermal regeneration systems, and other systems. Therefore, the basic understanding and appropriate mathematical modeling of these mechanisms are crucial in engineering designs. Several numerical simulation strategies are being pursued to achieve a long-term goal of virtual simulation of high-temperature degradation and failure of such components and systems. In this paper, as the first step of the effort in virtual high-temperature material failure simulation, the numerical simulation of the recently developed crack growth models, i.e. creep-fatigue, fatigue-oxidation, and creep-fatigue-oxidation models, are conducted. It is demonstrated that the models developed can be implemented in an efficient way for virtual life assessment and engineering design applications.