深海采矿水力提升管多场多尺度耦合非线性振动特性

Multi-field and multi-scale coupling nonlinear vibration characteristics of hydraulic riser in deep sea mining

针对深海水力采矿提升硬管流致振动失效问题,采用有限元法、Hamilton变分和虚功原理,建立了多场多尺度耦合作用下深海水力采矿提升硬管非线性振动模型,采用尾流振子模型模拟外部流体对大长径比提升硬管的非线性流体力,考虑了自身纵-横向耦合效应、外部海洋涡激效应以及内流流致振动效应。通过理论计算结果与模拟试验测量数据对比,验证了模型的有效性。研究表明,提升硬管在考虑纵横向耦合、涡激振动和大变形等非线性因素下,提升硬管的振动具有高度非线性特征。随着中间仓质量的增加,提升硬管的顺流向偏移量和均方根应力减小,横流向振动频带分布更广,其顶端受到的轴力更大。小周期、大幅值的波浪对提升硬管的振动、应力和顶端轴力影响颇为明显。

Aiming at the problem of flow induced vibration failure of deep-sea hydraulic mining riser,a nonlinear vibration model of deep-sea mining riser under multi-field and multi-scale coupling action was established by using finite element method,Hamiltonian variation and virtual work principle.Wake oscillator model was used to simulate the nonlinear fluid force of external flow of deep-sea mining riser with large length diameter ratio.The longitudinal-transverse coupling effect,external ocean vortex induced effect and internal flow-induced vibration effect were considered.The validity of the model was verified by comparing the theoretical calculation results with the measured data of the simulation experiment.The research shows that,considering the nonlinear factors such as longitudinal-transverse coupling,vortex induced vibration and large deformation,the cross flow(CF),in-line(IL)and longitudinal direction vibration of the mining riser have highly nonlinear characteristics.With the increase of the quality of the intermediate silo,the downstream offset and root-mean-square(RMS)stress of the mining riser decrease,and the axial force on the top of the mining riser increases.Small-period and large-value waves have obvious effects on the vibration,stress and axial force at the top of the mining riser.