基于Pasternak海床模型的椭圆余弦波浪荷载作用下埋置管线动力响应解析解

ANALYTICAL SOLUTION FOR DYNAMIC RESPONSE OF BURIED PIPELINE UNDER CNOIDAL WAVE LOAD BASED ON PASTERNAK SEABED MODEL

  • 摘要: 通过两阶段分析方法,针对椭圆余弦波作用下埋置管线的动力响应进行了探究。基于椭圆余弦波理论,采用Biot固结方程推导了非线性波浪作用下浅水区埋置管线所受的周期波浪压力;将管线考虑为动力Pasternak海床模型上的Euler-Bernoulli梁,将波浪动荷载施加到管线上获得无限长管线的动力响应偏微分控制方程;利用Fourier变换和Laplace变换并借助卷积定理得到管线挠度、速度、加速度、转角、弯矩和剪力的动力响应解。通过与三维有限元数值算例及既有试验结果对比验证了解析解的正确性与适用性。对椭圆余弦波作用下埋置管线的动力响应特性进行了敏感参数分析,结果表明:波浪高度H显著影响了波面形状与海床内波浪力大小,不同浪高下管线转角、弯矩和剪力的变化更明显,而挠度、速度和加速度响应敏感性则较低。

     

    Abstract: A two-stage analysis method is used to explore the dynamic response of the embedded pipeline under the action of cnoidal waves. Based on the cnoidal wave theory, using the Biot’s consolidation equation, the periodic wave pressure on the buried pipeline in the shallow water area under the action of nonlinear waves is derived. The pipeline is considered as a Euler-Bernoulli beam on the dynamic Pasternak seabed model, and the obtained wave load is applied to the pipeline. Through the force analysis of the micro-element body, the results of infinite-length pipeline placed on the Pasternak seabed are obtained. The response controls partial differential equation of the pipeline under seepage force and dynamic load; the Fourier transform and Laplace transform are used to simplify the equation, and the analytical solution is obtained with the help of the convolution theorem. The pipeline dynamic response solutions of deflection, velocity, acceleration, rotation angle, bending moment and shear force are obtained. Through comparative analysis with three-dimensional finite element calculation examples and existing test data, the correctness and applicability of the theoretical solution are verified. The sensitive parameters of the dynamic response characteristics of embedded pipeline under the action of cnoidal wave are analyzed; The results show that the wave height H significantly affects the shape of the wave surface and the wave force in the seabed; Under different H, the changes of pipeline rotation angle, bending moment and shear force are more obvious, while the sensitivity of deflection, velocity and acceleration response is lower.

     

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