埋地管线轴向振动特性的行波方法分析

考虑管-土及管-液间的相互作用,建立了埋地管线轴向振动的行波分析模型.由实验验证了行波方法的有效性,由数值算例研究了泊松耦合、连接耦合及土质条件对埋地管线振动特性的影响.算例结果表明,泊松耦合作用使系统在低频处出现了较多共振峰,忽略流体作用或仅将其视为固体填充物不能反映系统的该振动特性,系统频率的降低增大了系统在低频荷载作用下的危险性;由于流体边界的改变,连接耦合使系统各阶固有频率降低;随土体剪切刚度的增加,系统固有频率增大;土体阻尼可使系统振幅降低,但对系统频率影响不大.

Analysis of Behaviour of Axial Vibration of Buried Pipelines By Travelling Wave Method

Considering soil structure interaction (SSI) and fluid structure interaction (FSI), the axial vibration of a buried pipeline is analyzed with traveling wave method.The effectiveness of the algorithm is verified by an experiment.The influence of Poisson coupling, junction coupling and soil properties is studied in a numerical example.The numerical results show that amplitudes of vibration increase remarkably at some low frequencies when Poisson coupling is considered.If the fluid being ignored or just being regarded as a rigid filler,the characteristic of the system cannot be reflected,which may result in system risk under some low frequency dynamic actions.Due to the change of boundary conditions, junction coupling reduces the natural frequencies of the system.The natural frequencies of the system increase when the shear stiffness of soil increases.Soil damping reduces the amplitudes notably, but has little effect on the frequency of the system.