黏弹介质包裹的充液管道中低频轴对称波传播特性

研究埋地充液管道中低频轴对称波传播特性。将土壤考虑为黏弹介质,结合Kennard薄壳方程和Kelvin-Voigt线性黏弹性模型,引入土壤载荷矩阵,推导出土-管滑移情形下流体主导波和管壁压缩波的相速度表达式。通过数值模拟计算得到流体主导波和管壁压缩波的频散和衰减曲线并进行可靠性验证,分析两种波引起的管壁径向位移之比,讨论厚径比和品质因子对流体主导波传播的影响。结果表明,黏弹介质对流体主导波和管壁压缩波的相速度影响较小,但对衰减影响较大;流体主导波对管壁径向位移有较大的影响,是泄露噪声传播的主要载体;厚径比越大,流体主导波的相速度越大,衰减越小;而品质因子越大,流体主导波的频散和衰减都越小。研究结果可为埋地充液管道的泄漏检测提供一定的理论参考。

Propagation characteristics of low-frequency axisymmetric waves in fluid-filled pipes embedded in the viscoelastic medium

This study devotes to investigate the propagation characteristics of low-frequency axisymmetric waves in buried fluid-filled pipes.The surrounding soil is regarded as the viscoelastic medium.The Kennard thin-walled shell equations are combined with the Kelvin-Voigt linear viscoelastic model,and the soil loading matrix is introduced to derive the expressions of the phase velocity for both the fluid-dominated wave and the shell-compressed wave under the state of pipe sliding contact with soil.The dispersion and attenuation curves of the fluid-dominated wave and the shellcompressed wave are obtained by numerical simulation,and the reliability is verified.The ratio of the radial pipe wall displacements associated with the two waves is analyzed,-the effects of the thickness-to-radius ratio and the quality factor on the fluid-dominated wave are discussed.The results show that the viscoelastic medium has little impacts on the phase velocities of the fluid-dominated wave and the shell-compressed wave,but has great impacts on the attenuation;the fluid-dominated wave effects the radial displacement of pipe wall greatly and is responsible for the propagation of leakage noise;the phase velocity of the fluid-dominated wave increases and the attenuation decreases with the thickness-to-radius ratio;the dispersion and attenuation of the fluid-dominated wave decrease with the quality factor.The research results can provide some theoretical instruction and guidance for leakage detection of buried fluid-filled pipes.