Effect of social vehicle on bridge frequency identification using a test vehicle: theoretical and experimental validation

Although substantial efforts have been devoted to the vehicle scanning method (VSM) for bridges, reliably extracting bridge frequencies from the vehicle responses in real traffic remains a challenge. This paper proposes a three-stage framework to address the effects of social (on-going) vehicles on bridge frequency extraction for the vehicle-bridge system. Firstly, analytical solutions for the system’s dynamic responses are derived and validated against the finite element method (FEM). With these, the physical mechanism is unveiled of the effects of social vehicles on identifying favorable operating conditions for VSM. Using the FEM, a robustness analysis is conducted. The results indicate that: (1) social vehicles can have either a positive or negative effect on bridge frequency extraction, depending on time interval; (2) medium-to-high speeds and higher social vehicle weights improve both efficiency and accuracy; and (3) bridge frequencies can still be reliably identified even in the presence of road roughness and stochastic traffic flows. Finally, these findings are validated through experimental tests.