Vibration Analysis & Optimization Of Commercial Vehicle Driveline

The NVH of commercial-vehicle driveline directly affects easiness and safety of the whole vehicle. In order to reduce the vibration and noise, it is necessary for the vehicle manufacture to research the NVH of driveline and to carry out rational layout and design to the driveline which is the fundamental ways of all.In this paper, some research results of the domestic and foreign have been applied to analyze the vibration of driveline theoretically and experimentally. Furthermore, the vehicle chassis intermediate mounting cross member abruption problem due to the vibration of driveline has been resolved by optimizing the driveline layout. Based on system theory, this thesis gives out the optimal solution to the driveline vibration.This article mainly carried on the finite element analysis to the frame and the driveline intermediate mounting, the vibration acceleration test, the vibration frequency test, the experimental modality analysis, the stress test of the driveline crossbeam, and finally found the primary causes to the cracks of driveline's mounting cross member: The first cause is driveline's first order flexural resonance which caused by the engine. The second one is intermediate mounting's position does not locate in the node of vibration mode. The last one is that the intermediate mounting vibration isolation function is not good. In view of the question causes, this article proposed the concrete improvement program. At the same time, according to the vibration isolation theory, this paper adopts the driveline intermediate mounting which is dynamic stiffness, this enables the shaft intermediate mounting to have variable element at low frequency, it has big damping to reduce the driveline's vibration rapidly, or else lower rigidity with good vibration isolation effect.The verification result indicates that the solution of driveline vibration is effective. It reduced the vibration obviously, and resolved the cracks questions of driveline's intermediate mounting cross member fundamentally. This thesis connected with practical project in our company, has the characteristic of just pertinence and realistic meaning.