基于LS-DYNA海底悬空管道受坠物碰撞动力响应分析

The dynamic response analysis of submarine suspended pipeline impacted by dropped objects based on LS-DYNA

基于ANSYS/LS-DYNA动力学分析软件,采用非线性动力有限元法,对坠物撞击海底管道的过程进行数值仿真。通过大量的数值模拟得出:相同坠落物能量的情况下,悬空管道的凹陷损伤深度与裸露管道的相比偏小,且随着坠落物能量的增加,其差值增大;随着坠落物速度、坠落物质量的增大,管道撞击部位凹陷变形加剧,海底管道悬空段的最大振动幅值增大;相同坠落物能量的情况下,坠落物与悬空管道的接触面积越小,悬空管道的损伤深度越大;海床土体参数(剪切弹性模量、内摩擦角、密度)的变化对悬空管道的凹陷损伤深度及悬空段的最大振动幅值的影响较小。

Based on ANSYS/LS-DYNA-the dynamics analysis software, and using the nonlinear dynamic finite element method, the process of a submarine pipeline impacted by dropped objects is simulated. Through a lot of numerical simulations, the conclusion is drawn： the damage depth of suspended pipe is smaller than that of the bare pipe in the case of the same fall energy, and with the fall energy increases, the difference grows; with the increase of the falling object＇s speed and mass, the deformation of pipeline intensifies at the impact site, and the maximum vibration amplitude of submarine pipeline increases; when the fall energy is equal, the smaller the contact area of falling objects with pipeline is, the greater the damage depth of pipeline is; the change of seabed soil parameters（ shear elastic modulus, internal friction angle, density） has less influence on the suspended pipeline＇s dent depths and maximum vibration amplitude.