Using the Time-Weighted Residual Method in Forced Vibration Analysis of Timoshenko Beam under Moving Load

Document Type : Research Article

Authors

1 Department of Civil Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran

2 Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran

3 Department of Civil Engineering, Isfahan University of Technology, Isfahan , Iran

Abstract

In this study, formulation of a recently proposed time-weighted residual method has been developed for the vibration analysis of Timoshenko beams under moving loads. Employing pre-integration relations as well as equilibrium equations is the main idea of this method. In the first step of the proposed method, the time interval is subdivided into a number of sub-intervals and then the acceleration field in each time step is defined as the combination of an unknown function and a series of exponential basis functions with constant coefficients. Finally, the solution of the problem is computed by the time-weighted residual method along with exact satisfaction of the initial and the boundary conditions at the two ends of the beam. Storing the information of solution at each time step on the exponential coefficients is the most important advantage of this method so that the solution is progressed in time without the need to discretize beams and only by using an appropriate recursive relation to update the exponential coefficients. In order to investigate the accuracy and efficiency of the proposed method, the results of solving three sample problems of constant and accelerated moving load on the beams with different boundary conditions, are compared with the results of the finite element method. This comparison illustrates the speed and accuracy of the proposed method in estimating the internal shear forces and bending moments rather than those obtained by the finite element method.

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References

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