Fatigue Design and Analysis of the Vehicle Exhaust System's Hanger 2013-01-2609

The weight of an exhaust system on a modern vehicle is increasing because of all kinds of reasons, like engine power's increasing, more catalysts for emission control and more NVH (Noise, Vibration and Harshness) performance requirements. After the engine starting, the exhaust system was not only bearing a cyclical load from the engine, which mainly causing the vibration of the exhaust system, but also the loads from the road, which was transferred through the wheels, the suspension system and the body. Because the exhaust system always worked in these bad conditions, its structural strength, durability and life-time were analyzed in the paper, by numerical simulation and physical correlation.

By discretizing the exhaust system's CAD model, a finite element model was built. After restrict the finite element model as it in a real load condition, complete the structure stress analysis and Fatigue analysis of exhaust system's hanger with FEA analysis tools. Different designs, structures and materials are simulated during the analysis by using the fatigue simulation software. Select one kind of structure and material and verify the simulation results in the bending test. To process the data by using statistical theory, Fatigue simulations of components are proved to be mainly suitable with the experimental results. The experiments show that the simulation results are mainly reliable. All these simulations show an important instruct function and can replace some fatigue experiments in some certain occasions which will save the efforts and costs when designing a vehicle exhaust system.