【摘要】 水下悬跨输流管道在内外流作用下引起涡流振动和波激振动,对于地震较频繁地区,还将受到地震位移和加速度及地震引起的动水压力的作用,确保水下悬跨管道在各种冲击截荷作用下的安全,是管道可靠性设计及安全运行评估的重要内容。以水下管道悬跨段为研究对象,考虑内外流体与管道间的流固耦合作用,将管跨处理成等截面的直梁模型,两端入土端的约束等效为弹性支承,采用模态叠加法对其进行动态响应研究,通过算例分析了涡激频率、地震频率和管外流速对管跨振动响应特性的影响。从计算结果看出,跨长、管径对冲击的动态响应有着重要影响。本文分析方法对水下管跨的动态设计和可靠性分析评估具有参考价值。更多还原

【Abstract】 The submarine free spanning pipeline under internal and external flowing fluid action can be induced to vibrate due to vortex and water wave stimulation outside the pipe, especially when the constructed pipeline lays in seismic active zone, it would be subjected to the action of seismic loading like displacement or acceleration and hydrodynamic pressure excitation. The reliability design and safety assessment of underwater spanning pipeline acted by these shock loadings play important role to ensure its regular running. Taking the spanning pipeline as object model, simplifying it as simple beam with elastic supports at two ends, taking the fluid structures interaction(FSI) into consideration and using the mode superposition method to analyze the dynamic response, the effects of vortex and seismic frequencies and external flowing velocity on vibration characteristics are discussed through special model analysis. The results show that spanning length and outer diameter of the pipe have great influence on the dynamic response. The analysis method deduced is also valuable for design and reliability estimation of underwater spanning pipes.更多还原