A simulation technique that uses a finite element model for predicting vibration in the exhaust system was developed. The shapes of the flexible tube portions of the flexible joints, or vibration absorption joints, were faithfully modeled and the characteristics of the other parts were assigned numerical values. An accurate model of the ball joints was obtained by assigning numerical values to the dynamic properties of gaskets. The vibration force of the engine, which is the input for this system, was obtained using the sum of the inertial forces of the component parts and the rotational reaction force produced by cylinder combustion pressure. This made it possible to quantitatively predict the forces transmitted to the body from the exhaust hangers and to qualitatively understand exhaust system behavior. This in turn makes it possible to study the optimal locations for the exhaust hangers and the vibration absorption joints in the pre-development stages.
Article of Honda R&D Technical Review Vol.12 No.2 (127 - 134)