Bridge frequency extraction method based on contact point response of two-axle vehicle

Abstract

Extracting bridge frequencies through the vehicle-bridge contact point response is more effective than that of the response of the vehicle body and wheels. However, when driving on uneven roads, the pitch effect caused by the vertical and rotational motion of the vehicle will affect the extraction of bridge frequencies. Therefore, this study establishes a two-axle vehicle model considering the suspension system and pitch effect. Meanwhile, general equations for calculating the contact point response related to the model are proposed. The accuracy of the equations is verified through numerical simulation. The result shows that extracting bridge frequencies through the contact point response is better than that of the wheel response. Three parameters, such as suspension damping, road surface roughness and vehicle speed are investigated to demonstrate the reliability of extracting bridge frequencies through the contact point response.