Construction method of ballast track-bridge dynamic coupling model

Abstract

The invention discloses a construction method of a ballast track-bridge dynamic coupling model. The method comprises the steps that a ballast track bed discrete element model reflecting the complex shape and the contact relation of a railway ballast is established through a discrete element method, and the model is used for representing a particle unit accumulation structure, the contact force between particles and coupling surfaces and an equivalent node transplantation load; a continuous medium sleeper finite element model and a bridge finite element model are established by utilizing a multi-body finite element method, wherein the models are used for representing a continuum grid structure, node displacement deformation, surface node position coordinates and an element connection relationship; and a ballast track-bridge dynamic coupling model is constructed based on a discrete element and multi-body finite element coupling method. According to the method, the irregular shape and themutual meshing and stacking relation of the ballasts on the mesoscopic level are fully considered, meanwhile, the interaction between the macroscopic ballast bed and the upper and lower structures can be reflected, and refined simulation of the complex mechanical behaviors of the ballast track on the bridge under the train load effect is achieved.

Description

technical field [0001] The invention relates to the technical field of track construction, and more specifically, to a method for constructing a ballasted track-bridge dynamic coupling model. Background technique [0002] In the process of high-speed railway construction, in order to avoid fertile land and save land, the construction policy of "replacing roads with bridges" was advocated, which made the high-speed railways on bridges huge. For example, the bridge foundation of the Beijing-Shanghai high-speed railway accounts for more than 80% of the entire line. Ballasted track and ballastless track are the main track structure types of high-speed railways. In comparison, ballasted track has the advantages of low cost, low vibration and noise, strong adaptability, and convenient maintenance and repair. Therefore, the main high-speed railways on bridges in my country Application of ballasted track, especially in long bridge sections, ballasted track is an inevitable choice. ...

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Problems solved by technology

After analysis, the ballasted track model on bridges based on the discrete element method can effectively reflect the characteristics of the bulk medium of the ballasted ballast bed, but it simplifies the sleepers and bridges into fixed walls, which makes it difficult to truly simulate the interaction between multi-layer structures

[0006] The existing numerical simulation methods for ballasted tracks on bridges mainly have the following defects: 1) The finite element method regards the ballasted bed as a homogeneous whole, considers the geometric profile of the ballast bed for unit processing, and the units satisfy the displacement continuity relationship , although a complete track-bridge system model can be established, it can only study the instantaneous mechanical state of the ballast bed under load from the macroscopic level, and cannot simulate the occlusal relationship of the ballast particles in the bulk ballast bed and the plastic deformation caused by the long-term load

2) The discrete element method only focuses on the structure of the local ballast bed, considers the complex shape of the ballast, and studies the cumulative effect of long-term loads on the change of the state of the ballast bed. certain deviation

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