Techno Press
You logged in as. Techno Press

Structural Engineering and Mechanics
  Volume 52, Number 5, December10 2014 , pages 997-1017
DOI: https://doi.org/10.12989/sem.2014.52.5.997
 


The modal characteristics of non-uniform multi-span continuous beam bridges
Lu-ning Shi, Wei-ming Yan and Hao-xiang He

 
Abstract
    According to the structure characteristics of the non-uniform beam bridge, a practical model for calculating the vibration equation of the non-uniform beam bridge is given and the application scope of the model includes not only the beam bridge structure but also the non-uniform beam with added masses and elastic supports. Based on the Bernoulli-Euler beam theory, extending the application of the modal perturbation method and establishment of a semi-analytical method for solving the vibration equation of the non-uniform beam with added masses and elastic supports based is able to be made. In the modal subspace of the uniform beam with the elastic supports, the variable coefficient differential equation that describes the dynamic behavior of the non-uniform beam is converted to nonlinear algebraic equations. Extending the application of the modal perturbation method is suitable for solving the vibration equation of the simply supported and continuous non-uniform beam with its arbitrary added masses and elastic supports. The examples, that are analyzed, demonstrate the high precision and fast convergence speed of the method. Further study of the timesaving method for the dynamic characteristics of symmetrical beam and the symmetry of mode shape should be developed. Eventually, the effects of elastic supports and added masses on dynamic characteristics of the three-span non-uniform beam bridge are reported.
 
Key Words
    modal perturbation method; analytic solution; non-uniform beam; elastic support; added mass; mode shape
 
Address
Lu-ning Shi, Wei-ming Yan and Hao-xiang He: Beijing Laboratory of Earthquake Engineering and Structure Retrofit, Beijing University of Technology, Beijing 100124, China
 

Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2025 Techno Press
P.O. Box 33, Yuseong, Daejeon 305-600 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: admin@techno-press.com