深海采矿机械液压系统非线性耦合振动机理及可靠性研究

Because of excitation of extreme marine environments,hydraulic system of deep-sea mining machine will give birth to coupled vibrations that lead to sealing failure and fatigue failure of hydraulic components.Therefore it is very important significance that the safety and reliability of hydraulic system for deep-sea mining machinery are studied. The project will regard the hydraulic system of the deep-sea mining machinery as the research object. Its impacts of sealand reliability of hydraulic components based on the fluid-structure interaction effect are researched.These effects on pipe's vibrations characteristics of high pressure and relative water speed under deep-sea environment are studied, and the dynamic response laws of pipe's vibrations caused by different pressure and water speed are revealed. Pipeline's vibration caused by external excitations play a role on the hydraulic oil pressure fluctuation.Because of the fluid-structure interaction effects among pipeline and hydraulic oil and seal rings caused by the hydraulic pressure changes,the combination interface displacements will be simulated and tested.The internal relates between the sealing interface displacements and pressure pulsation in the pipeline's joints will be set up.On the basic of getting the rules of pipeline junction interface displaces,sealed principles and methods of hydraulic system for deep-sea engineering mechanical will be proposed.Hydraulic system component fatigue damage rules due to pressure fluctuation will be researched,and the reliability models of the typical hydraulic components will be established.The project's achievements will provide theories and technologies for hydraulic system of deep-sea engineering machinery on optimal design,sealed principle and reliability design.

由于极端海洋环境的激励，深海采矿机械液压系统会产生耦合振动，耦合振动导致密封失效和液压元件疲劳破坏，研究深海采矿机械液压系统振动机理及可靠性具有重要的意义。本项目针对深海采矿机械液压系统受外部激励引起液压管道系统耦合振动，振动对系统密封性与液压元件可靠性影响展开研究：研究外部高压、海水冲击对液压系统管道振动的影响，揭示不同水压、不同水流速度作用下液压软管振动特性规律；研究外部激励引起的管道振动对液压油压力波动的相互作用机理，深入研究液压油压力波动导致的管道-液压油-密封圈三者流固耦合效应，揭示界面处密封元件、管接头位移变化与压力波动之间的内在关系；在获得管道结合处界面位移变化规律的基础上，提出深海采矿机械液压系统密封原理和方法；研究液压系统振动造成液压元件疲劳破坏规律，建立深海环境下液压系统可靠性模型。研究成果为海洋工程机械液压系统优化设计和密封原理以及液压系统可靠性设计提供技术支持。

由于极端海洋环境的激励，深海采矿机械液压系统会产生耦合振动，耦合振动导致密封失效和液压元件疲劳破坏，因而深海采矿机械液压系统流固耦合振动机理研究引起国内外的重视。课题组针对液压系统流固耦合振动与压力脉动衰减进行了研究。首先研究了液压系统动力源（柱塞泵）引起的液压系统流量与压力脉动的影响，研究分析不同工况下对柱塞泵流体特性的影响，得出流量脉动率与斜盘倾角、主轴转速和工作压力成反比；柱塞腔内液压力随工作压力的增加而增加；并根据相应的频谱特性曲线，得出脉动幅值最大处的频率。第二是研究了液压系统管道布局与管道类型对液压系统的影响，由于液压管道管径和弯曲角度对固有频率的影响较为显著，考虑不同弯曲半径和不同弯曲角度下的管道耦合仿真分析，并研究了管道内流体和固体随管道曲率的变化规律。第三是研究了液压系统压力脉动衰减器，结合了H型和K型各自的滤波频率范围的优点，首次提出了二级复合式流体滤波器，它由两个并联的复合式流体滤波器构成，达到了对液压系统压力脉动衰减频率宽的目标。最后研究了液压系统密封性能，建立了管接头密封结构的简化模型，分析了密封圈在预密封、压缩和流体脉动压力加载三阶段的应力变化情况，并研究了流体脉动压力加载阶段密封圈Von-Mises应力和主密封面接触应力，以及密封圈的失效变化规律和密封性能趋势。完成了一部有特色的计算流体力学专著（第2作者）。