索杆梁耦合结构分析模型及其应用研究

Analysis model of cable-rod-beam coupling structure and its application

为了研究索杆滑动连接特性对索杆梁耦合结构受力的影响,定义了由一个通过滑动节点连接的三节点活动滑移索单元和多个两节点非活动滑移索单元组成的单元组,基于更新拉格朗日法推导了三节点直线型滑索单元几何非线性刚度矩阵,并建立了输电线路索杆梁耦合结构有限元模型。通过高压架空输电线路耐张段的非线性静力调索分析验证了耦合结构模型的可行性,探讨了耦合结构在导线发生断裂失效后的动响应变化规律及其传播特性。计算结果表明,导线静态张力与规范设计参数相差较小,可用于后续分析。考虑滑移的导线张力在导线断裂初期有短暂增加的趋势。导线断裂对邻近绝缘子和铁塔横担杆件的受力有明显的影响,且动响应的传播会导致邻近塔的导线张力增加。

In order to study the influences of gliding characteristics of transmission lines on the tension forces of structural members in cable-rod-beam coupling structure, a model of string of sliding cable elements （SCEs） consisting of one active three-node SCE passing through the ＂slider point＂ and multiple inactive two-node SCEs was put forward. Based on updated Lagrangian （ U. L. ） formulation, the geometrically nonlinear stiffness matrix of 3-node straight sliding cable element was deduced. The finite element model of transmission line structure was established. Taking a high voltage overhead transmission line as an example, the initial equilibrium state of the coupling system was determined by carrying out nonlinear static analysis, and the dynamic tension forces under cable rupture were calculated. The results show that the static tension force of lines can be used in the succeeded dynamic analysis due to that there is only small difference between the static tension force obtained and the noramal design parameter. The tension force of lines considering gliding characteristics will increase just after cable rupture. The cable rupture has towers, and the shock wave due to cable rupture could raise the forces of significant effect on the forces on insulators and the adjacent conductors.