Abstract
This paper describes the overall procedures for the lifetime prediction of the exhaust manifold. Thermo-mechanical fatigue tests with specimen were accomplished to obtain the number of cycles to failure. The lifetimes in bench tests were calculated by the computational fluid dynamics (CFD) and the finite element method (FEM). The strain gauges available for the high temperature were attached to the surface of exhaust manifold and the measurements were performed for engine bench and vehicle driving conditions. The distribution of the customer failure mileage shows the results are reasonable. The developed procedures can be used as a useful tool not only for validating the durability test codes for the components of the exhaust systems but also for predicting the lifetime of the exhaust manifold in design stage, thus reducing development time and cost.
Keywords: Thermo-mechanical fatigue, FEM, strain measurement, lifetime, exhaust manifold