Adaptive Amplifier for a Test Vehicle Moving over Bridges: Theoretical Study

Y. B. Yang, Z. L. Wang*, K. Shi, H. Xu, J. P. Yang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


A vibration amplifier is first proposed for adding to a test vehicle to enhance its capability to detect frequencies of the bridge under scanning. The test vehicle adopted is of single-axle and modeled as a single degree-of-freedom (DOF) system, which was proved to be successful in previous studies. The amplifier is also modeled as a single-DOF system, and the bridge as a simple beam of the Bernoulli-Euler type. To unveil the mechanism involved, closed-form solutions were first derived for the dynamic responses of each component, together with the transmissibility from the vehicle to amplifier. Also presented is a conceptual design for the amplifier. The approximations adopted in the theory were verified to be acceptable by the finite element simulation without such approximations. Since road roughness can never be avoided in practice and the test vehicle has to be towed by a tractor in the field test, both road roughness and the tractor are included in the numerical studies. For the general case, when the amplifier is not tuned to the vehicle frequency, the bridge frequencies can better be identified from the amplifier than vehicle response, and the tractor is helpful in enhancing the overall performance of the amplifier. Besides, the amplifier can be adaptively adjusted to target and detect the bridge frequency of concern. For the special case when the amplifier is tuned to the vehicle frequency, the amplifier can improve the vehicle performance by serving as a tuned mass damper, as conventionally known. This case is of limited use since it does not allow us to target the bridge frequencies. Both bridge damping and vehicle speed are also assessed with their effects addressed.

Original languageEnglish
Article number2150042
JournalInternational Journal of Structural Stability and Dynamics
Issue number3
StatePublished - Mar 2021


  • Adaptivity
  • amplifier
  • bridge
  • frequency
  • test vehicle
  • tuned mass damper
  • vehicle scanning method


Dive into the research topics of 'Adaptive Amplifier for a Test Vehicle Moving over Bridges: Theoretical Study'. Together they form a unique fingerprint.

Cite this