关键词: 正交异性钢桥面板, 梯形加劲肋, 局部振动, 板梁单元

Abstract:

Proposed in this paper is a combined plate-beam element method to calculate the local vibration of the orthotropic steel bridge deck with trapezoid stiffened ribs,which is used in the long-span steel bridge. In this method,the top plate and the trapezoid stiffened rib are respectively taken as the flat shell element and the plate-beam element,and the corresponding displacement model is established according to the deformation coordination relationship between the plate and the rib. Moreover,the stiffness matrix of the combined plate-beam element is obtained based on the energy-variation principle,and the consistent mass matrix and the consistent load matrix are obtained based on the shape function of each sub-element. Then,the finite dynamic equilibrium equations are obtained. Finally,a calculation program of dynamic finite element is presented for the combined plate-beam element,and the first 10 consequent natural frequencies are compared with those of the shell finite element,finding that the latters accord well with the formers. Thus,the proposed method proves to be feasible and efficient.

Key words: orthotropic steel bridge deck, trapezoid stiffened rib, local vibration, plate-beam element