Vibration characteristics of steering wheel in passenger car are investigated by using the four-pole parameter method within the frequency range of interest corresponding to the engine idling state. Before the four-pole parameter method is applied to the test passenger car, the method is tested with a simple structure in order to check the experimental procedure.
For the purpose of analysis, the passenger car is divided into two systems, the body without engine and the steering wheel system including deck cross member, steering column and steering wheel. The four-pole parameters for each system are experimentally obtained, and then the two system models are connected in series to obtain four-pole parameters of the total system. To apply the four-pole parameter method to the steering wheel system, the system is modeled as a single degree of freedom system, since the preliminary modal test results reveal that only the fundamental mode lies between the frequency range of interest.
Experimental results show that the predicted four-pole parameters of the total system using the method are in good agreement with the testing results. It is also found that there is little dynamic interaction between the body and the steering wheel system, implying that the investigation of the steering wheel system alone is sufficient to improve its vibrational behavior.
