Theoretical and Laboratory Experimental Studies of Vehicle-Excited Bridge Vibration

Yang, JING (2017) Theoretical and Laboratory Experimental Studies of Vehicle-Excited Bridge Vibration. PhD thesis, University of Liverpool.

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Abstract

Theoretical studies of vehicle-bridge interactions have been conducted extensively, but a relatively much smaller amount of work concerns experimental studies of this problem. Full-scale tests of vehicle-bridge vibrations can be done to estimate the performance of the vehicle-bridge system or validate theoretical models, but are expensive compared with small-scale experiments in a lab. In addition, continuous bridges are paid relatively much less attention compared with simply supported bridges in the literature. This thesis is dedicated to the theoretical and the laboratory experimental studies of a four-span continuous plate structure subjected to moving cars. Firstly, the mode shapes of a multi-span continuous beam are approximated by using a number of sinusoidal functions which are the mode shapes of the beam with simply supported boundaries. The analytical solution of the continuous beam subjected to a moving force can be derived as one simple expression for the whole length of the beam based on the approximated modes, and the contributions of bridge frequencies to the modal responses of the beam would be clearly shown in the analytical solution, which can provide guidance for identifying the modal properties of the beam. This idea is illustrated by a two-span beam. The response of a simple beam subjected to a moving force is compared with that of a two-span continuous beam. The second part of this thesis is about the vehicle-bridge interaction and separation, which are investigated by using the moving sprung mass model. After that, a general approach of simulating vehicle-bridge interactions is applied to a four-span plate structure traversed by one or two moving cars at different speeds. There are two types of situations for two cars: the two cars are either separated or connected together with pitching rotation allowed for each car. The adjacent loads of two-connected-cars are almost equal distance away from each other, which is like a series of moving equidistant loads. A Laser Vibrometer is used to measure the car speeds, and four laser displacement transducers at each span are utilized to capture the structural responses. The theoretical model of the rig is updated and validated with experimental results. A frequency spectrum analysis of measured structural displacements and an in-depth parametric analysis based on the validated theoretical model are carried out.

Item Type:	Thesis (PhD)
Divisions:	Faculty of Science and Engineering > School of Engineering
Depositing User:	Symplectic Admin
Date Deposited:	21 Dec 2017 11:17
Last Modified:	19 Jan 2023 06:52
DOI:	10.17638/03010743
Supervisors:	Ouyang, HUAJIANG ORCID: 0000-0003-0312-0326
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3010743