Physics-Based Reliability – Discussions & Case Studies in Aerospace

SUMMARY & CONCLUSIONSThis paper provides a discussion of four physics-based reliability case studies in aerospace applications. The first two show how physics-based reliability applied during the design phase improved the resultant design. The second two demonstrate how physics-based reliability were instrumental in resolving the failures that resulted in the accidents of the Challenger and Columbia space shuttles.In the first case study, physics-based reliability was used to understand the failure mechanism and the reliability of frangible joints, resulting in weight reduction and cost saving while achieving the reliability required by NASA and industry. In the second case study, physics-based reliability was used to model the probability of a crack in the inter race of a bearing for a rocket engine turbopump which led to the resolution of a major development issue. In the third case study, the O-ring failure that resulted in the Challenger accident was analyzed using physics-based reliability. The result was a solution that enabled a return-to-flight decision. In the fourth case study, the Columbia accident was analyzed using a physics-based reliability process that resulted in design and process improvements which led to a return-to-flight decision.