This paper describes the dynamic analysis of prestressed Bernoulli beams resting on a two-parameter elastic foundation under a moving harmonic load by the finite element method. | Vietnam Journal of Mechanics, VAST, Vol. 28, No. 3 (2006), pp. 176- 188 DYNAMIC ANALYSIS OF PRESTRESSED BERNOULLI BEAMS RESTING ON TWO-PARAMETER FOUNDATION UNDER MOVING HARMONIC LOAD NGUYEN DINH KIEN AND TRAN THANH HAI Institute of Mechanics, Vietnamese Academy of Science and Technology Abstract. This paper describes the dynamic analysis of prestressed Bernoulli beams resting on a two-parameter elastic foundation under a moving harmonic load by the finite element method . Using the cubic Hermitian polynomials as interpolation functions for the deflection, the stiffness of the Bernoulli beam element augmented by that of the foundation support and prestress is formulated . The nodal load vector is derived using the polynomials with the abscissa measured from the left-hand node of the current loading element to the position of the moving load . Using the formulated element, the dynamic response of the beams is computed with the aid of the direct integration Newmark method. The effects of the foundation support, prestress as well as excitation frequency, velocity and acceleration on the dynamic characteristics of the beams are investigated in detail and highlighted. " 1. INTRODUCTION The dynamic analysis of beams under moving loads plays an important role in the field of railway and bridge engineering, and has attracted much attention from researchers for many years. The early work on the topic has been described by Timoshenko et al. in [1], where the governing equation for a uniform Bernoulli beam subjected to moving harmonic force with constant velocity was solved by the mode superposition method . In [2], Fryba presented a solution for vibration of simply supported beam under moving loads and axial forces . Employing the traditional 2D Bernoulli beam element, Thambiratnam a nd Zhuge [3] computed the dynamic amplification factor for beams resting on a Winkler elastic foundation subjected to moving loads. Chen et al. [4] investigated the response of infinite .
