基于多柔体动力学理论的接触网找形方法

基于绝对节点坐标法描述的多柔体动力学理论,提出了一种接触网找形方法.考虑到接触网大变形的非线性问题,采用基于绝对节点坐标法(ANCF)描述的变长度索单元对接触网进行离散,通过多柔体动力学理论对变长度索单元的动力学方程进行推导;根据静力平衡条件对动力学模型进行退化处理,推导了张紧索单元的找形方程.同时考虑接触线的预驰度问...

FORM-FINDING METHOD OF RAILWAY CATENARY BASED ON THE FLEXIBLE MULTIBODY DYNAMICS THEORY

It proposed a form-finding method for railway catenary based on the dynamic theory, which is described by absolute nodal coordinate formulation (ANCF) in the flexible multibody dynamics theory. In the context of nonlinear problems, the catenary is modeled using ANCF cable element based on the flexible multibody system formulation and variable-length element theory. According to the static equilibrium conditions, the dynamic model is degraded and the form-finding model of tensioning structure is built. Meanwhile, considering the pre-sag design requirement of the contact wire, the models of contact wire and steady arm are separated out and solved using the form-finding model of tensioning structure. The force of droppers is updated for computing the equilibrium of droppers and messenger wire system according to the form-finding model. The equilibrium of railway catenary is determined. Three examples are adopted for verifying the proposed method, the results show that the proposed method can compute the equilibrium configuration of railway catenary exactly and the maximum relative error is less than 2%, which satisfies the engineering requirement.