基于集中质量法的水下缆索破断动力学仿真

Dynamics Simulation of Breaking Underwater Cable Based on Lumped Mass Method

为数值模拟和预测缆索破断的动力学特性,基于集中质量法建立了水下缆索的动力学模型,采用经典的Runge-Kutta法进行数值解算;通过设置合适的边界条件实现对缆索破断的模拟,并对快速破断和缓慢破断的动力学行为进行了研究;数值模拟结果表明,破断点及其附近节点的速度在破断后极短的时间内达到最大值,之后扰动以弹性波的形式向破断点以远的方向传播;缓慢破断时张力和速度在缆索上能够更加均匀地分布,使得动能在整条缆索上的分布更加均匀,从而能够高速运动的缆索节点数目更少,节点维持高速运动的时间更短;揭示了扰动以弹性波的形式在破断缆索上的传播机制,用数值的方法证明缓慢破断比快速破断更加安全。

In order to numerically simulate and predict the dynamics behavior of a breaking cable, the dynamics model of the underwater cable is built up based on the lumped mass method, and the classical Runge-Kutta method is used to solve the model The breaking cable is simulated by exerting appropriate boundary conditions. The dynamics behaviors of immediately and slowly breaking cable are studied. The results indicate that the velocity of the nodes around the breaking point reaches the maximum in a very short time, and then the disturbance propagates outside in form of elastic-wave. Tension and velocity distribute more uniformly along the cable in case of breaking slowly, leading to a more uniform distribution of kinetic energy in the cable, The number of nodes with high velocity is reduced and the duration of high velocity motion is shortened; The simulation reveals the mechanism of disturbance＇s propagation in the form of elastic wave and proves that slow breaking cables are less dangerous than fast breaking ones.