Vibration control analysis of vehicle steering system based on combination of finite-element analysis and modal testing

Determining the natural frequency distribution is of great importance in studying the vibration of the steering system in a commercial vehicle. A high-speed vibration frequency sweep experiment on an unladen commercial vehicle was conducted to determine the resonance frequency of the vehicle components. A vibration waterfall plot of the collected vibration data revealed that the cause of the vibration was frequency coupling resonance between the steering wheel vibration frequency and the second-order rotation frequency of the tire. Thus, a combined optimization of the structure of the rigid bearing parts of the steering fixed support and the steering column structure was proposed. A combination of finite-element analysis and modal testing method was undertaken to verify the effectiveness of the proposed combined structural improvement; the results demonstrated the consistency of the combined methods and showed that the natural frequency of the improved steering structures, together with the vibration amplitude, had changed. This study demonstrated the feasibility of the combined modal testing and finite-element analysis method, provided more information on the vibration transfer characteristics related to the vehicle subsystems, and provided a reference for the structural design of steering systems with reduced vibration.