On The Vibration Reduction Of The Steering Of A Three-wheeled Motorcar

The vibration reduction was studied on the steering wheel of a three-wheeled motorcar here.At first, the vibration was tested under the condition of its original situation, and the causes of the vibration were analyzed. It was found that the vibration on the steering wheel was quite serious. Based on the theory of modal analysis and harmonic response, the vibration characteristics of the steering wheel was analyzed and its vibration response was simulated by means of the large commercial finite element calculation software ANSYS. The vibration excitation are mainly from the engine's first order unbalanced inertial and the inflammation explosive forces, so the harmonic response analysis was carried out in the relevant frequency band, which includes the frequencies when the engine operates in some revolutions in common use, such as the revolution v/ith the maximum output torque and the rated revolution.The experiment modal analysis of the steering wheel was also conducted at the same time. The obtained results were in good agreement with those obtained by the finite element analysis, which proved that the model of finite element analysis was quite correct and dependable.Combining experiment modal analysis and FEA calculation analysis, the vibration characteristics of the steering wheel were obtained. In order to improve its vibration situation, a partial modification design was made on the steering wheel. The FEA simulation and experiment proved that the modification was effective to reduce the vibration of the steering wheel.Based on the idea of structural parameter design, a parametric FEA modeling and post processing software was developed by ANSYS's parameterization design language ( APDL ) and visual programming tool( Delphi ).According to vibration isolation theory, the isolation system of the motorcar was analyzed, and some relevant parameters affecting isolation characteristic of the motorcar's suspend were found out. Based on the research and analysis on theisolation performance of the isolators with which the motorcar equipped originally, new isolators were designed. The experiment results indicated that the new isolators had good performance, and were able to obviously improve the vibration situation of the motorcar.Added with the relevant theory, this thesis made use of two methods - vibration isolation and optimization of the vibrating structure to reduce the vibration of the steering wheel. Finally vibration was reduced by over 80% when the engine operated in common revolutions, and satisfied result was obtained.