船舶撞击下的车—桥耦合系统动态响应分析

摘要

文章将“船桥碰撞”与“车桥耦合”联系在一起进行研究,建立了斜拉桥、轻轨和船舶的三维非线性精细有限元模型,研究了轻轨列车-斜拉桥动态耦合系统在船舶碰撞下的动态响应.数值模拟过程分以下四步:桥梁初始成桥状态模拟,轻轨列车—斜拉桥动态耦合模拟,船舶与桥梁的碰撞模拟和桥梁—火车—船舶相互作用模拟.桥梁初始状态及大变形通过更新拉格朗日法和共旋转推导法来实现.通过与平面杆系有限元模型的计算结果进行比较,证实了全三维有限元建模方法在车—桥动态耦合响应分析中应用的准确性.研究通过基于罚函数的动态接触方法来实现车—桥耦合和船舶的碰撞过程,采用递归谱二分法的并行计算技术来缩短计算时间,基于显式中心差分插值法来进行数值求解,该方法证明在分析车—桥—船之间的耦合动态响应是一种有效的技术,为设计阶段模拟桥梁的动态特性提供了有效手段.结果表明,当发生船—桥碰撞时,轻轨列车运行到主桥塔附近行车安全的影响最大.%The work about dynamic simulation of bridge-ship collision and its impact on the moving train is introduced.The three-dimensional (3D) non-linear finite element (FE) model of cable-stayed bridge,light metro and ship is presented.The numerical simulation consists of four steps:simulation of initial bridge state,bridge-train coupling simulation,bridge-ship collision simulation and bridge-train-ship interaction simulation.The initial bridge state and large deformation are fulfilled by using Update Lagrange Formulation and Co-rotational formulation.Validation of the approach and FE models are achieved by comparing the numerical results with the calculation of validated plane bars models.The bridge-train coupling and ship impact are realized through the penalty-based dynamic contact-impact algorithm.Computation time was reduced by parallel domain decomposition with Recursive Coordinate Bisection (RCB) method.Explicit central difference integration is employed in this paper to accomplish the numerical computation.The proposed approaches are proved to be effective to apply in the bridge,train and ship dynamic analysis,and the 3D numerical model can improve the understandings of bridge dynamic behaviors during bridge design.The results show that the ship impact is the most dangerous for train safety when the train is arriving at the main tower.