双源液压管网激振机理研究

发布时间：2018-06-07 23:08

  本文选题：液压激振 + 双源液压　； 参考：《太原理工大学》2013年博士论文

【摘要】：针对振动机械中大量使用的基于惯性激振的振动筛,其偏心块在旋转过程中易在非振动方向产生离心力的分力,从而造成振动效率低及参数不易调节等问题,本文提出了一种新的液压激振机理,利用激波器转阀的快速换向使管内流体压力、流速发生急剧变化,从而使管网产生可控的多点激振和多自由度振动的新型液压激振方式。对液压激振作用下流体与管道的耦合振动特性进行了仿真分析与试验研究,实现了由液压缸-激波器组成的双源液压激振作用下管网的振动控制,并对液压激振作用下的三维振动筛进行了应用研究。本文首先建立了液压激振波的数学模型,采用特征线法(MOC)编程求解出了液压激振系统流体的动力学特性,数值模拟了管道在液压激振波作用下断面激振压力与变频器频率、系统压力之间的关系,表明液压激振系统的振动参数可通过调频与调压实现可控。在液压激振机理的基础上构建了液压激振试验系统,采用压力变送器及数据采集卡对管道内流体的动态特性进行了检测,通过时域分析与频域分析相结合的方法对流体的动力学特性进行了试验研究,验证了液压激振系统的可控性。首次提出了由液压缸-激波器组成的双源液压激振的振动机理,引入传递函数对系统各环节进行了数学描述,数值模拟了脉动流作用下液压激振系统主要部件的运动学特性,揭示了由液压缸-激波器组成的液压激振系统的双源特性。建立了液压激振波作用下充液管道流固耦合的振动方程,采用特征线-有限元法(MOC-FEM),把管道简化为梁模型,将特征线法计算出的流体激振压力施加到管道的有限元节点上,在保证流体特征线节点与管道的有限元节点相重合的前提下,用Newmark法编程将流体各断面横向激振压力施加到管道的有限元节点上,求得了管道横向各断面处及轴向的振动响应,通过FFT法获取了幅频特性并与试验进行了对比分析。构建了基于管网的液压激振试验系统,通过试验对比分析,确定了可进行振动利用的管网激振系统并进行了振动测试,对影响管道振幅及振动频率的因素进行了回归分析,拟合出了变频器频率和系统压力与管道振幅及振动频率的函数关系。将试验时程曲线与数值模拟进行了对比,振动波形在振幅及振型上具有较好的吻合度。对管道固液耦合振动方程进行了拉氏变换,根据振动方程的传递函数得到了位移频响函数,采用最小二乘法、五点滑动平均法编程对振动信号中的随机干扰信号及高频信号进行了平滑预处理。采用实模态最小二乘迭代法对振动信号进行了试验模态参数的频域识别,提取出了管道空间振动的试验模态参数,并与时域识别的ITD法和STD法进行了对比分析,为确定主振体的最佳振动频率提供了依据。为研究液压管网激振下的三维振动筛,设计了将振动筛板简化为弹性板的管网液压激振测试系统,对影响弹性板振幅的因素进行了回归分析,拟合出了变频器频率和系统压力与弹性板振幅的函数关系,揭示了以弹性板为载体的液压激振系统的可控性。建立了液压激振作用下三维振动筛的空间合振动方程,对振动轨迹进行了仿真合成,并与平面复合振动筛的运动轨迹进行了对比。研究了物料在液压激振三维振动筛上的运动特性,揭示出在液压激振作用下沿振动筛长度方向的运动表现为振幅与频率不同的多点激振和多自由度的振动,有利于物料在振动筛上不同部位的振动需求,对物料的筛分优势明显。本文通过理论分析与试验研究相结合的方法,提出了将主动产生的液压波动应用到管道振动控制上的新的液压激振机理,为这种新的液压激振方式的产生及控制提供了理论依据与试验研究,揭示了主动液压激振波作用下管道振动的可控性,这对深化液压振动理论及振动利用工程具有重要的理论与实践意义。
[Abstract]:In view of the inertia excited vibration sieves used in the vibration machinery, the eccentric block is easy to produce centrifugal force in the non vibration direction during the rotation process, which causes the low vibration efficiency and the parameters not easy to adjust. In this paper, a new mechanism of hydraulic excitation is proposed, and the rapid change of the valve is used to make the fluid inside the tube to make the fluid inside the tube. The pressure and flow velocity change rapidly, which makes the pipe network produce a new type of controllable vibration excitation mode with multi point excitation and multi degree of freedom vibration. The coupling vibration characteristics of fluid and pipe under the action of hydraulic excitation are simulated and tested. In this paper, the mathematical model of the hydraulic excitation wave is set up first, and the characteristic line method (MOC) is used to solve the dynamic characteristics of the fluid in the hydraulic excitation system, and the numerical simulation of the pressure and frequency of the frequency converter under the action of the hydraulic excited wave is numerically simulated. The relationship between the pressure of the system indicates that the vibration parameters of the hydraulic excitation system can be controlled by frequency modulation and voltage regulation. On the basis of the mechanism of hydraulic excitation, a hydraulic vibration excitation test system is constructed. The dynamic characteristics of the fluid in the pipeline are detected by the pressure transmitter and the data acquisition card, and the time domain analysis and frequency domain analysis are carried out. The dynamic characteristics of the fluid are tested by the combined method, and the controllability of the hydraulic excitation system is verified. The vibration mechanism of the dual source hydraulic excitation composed of hydraulic cylinder shock wave is first proposed, and the transfer function is introduced to describe each link of the system. The numerical model is the main part of the hydraulic excitation system under the action of the pulsating flow. The two source characteristics of the hydraulic vibration excitation system composed of hydraulic cylinder and shock wave are revealed. The vibration equation of fluid solid coupling in the fluid filled pipe under the action of the hydraulic excited wave is established. The characteristic line finite element method (MOC-FEM) is used to simplify the pipe as the beam model, and the fluid excitation pressure calculated by the characteristic line method is applied to the pipe. On the finite element node, on the premise of ensuring the joint of the fluid characteristic line node and the finite element node of the pipe, the lateral vibration pressure of each section of the fluid is applied to the finite element node of the pipe by the Newmark method, and the vibration response of the transverse section and the axial direction is obtained. The amplitude frequency characteristic is obtained by the FFT method and the test is carried out with the test. The hydraulic excitation test system based on the pipe network is constructed. Through the comparison and analysis of the test, the vibration system which can be used for vibration utilization is determined and the vibration test is carried out. The regression analysis is made on the factors affecting the amplitude and frequency of the pipeline, and the frequency and pressure of the frequency converter and the amplitude and vibration of the pipeline are fitted out. The test time curve is compared with the numerical simulation. The vibration waveform has a good coincidence in amplitude and mode. The Lagrangian transformation is carried out on the coupling vibration equation of the pipe and liquid. The displacement frequency function is obtained according to the transfer function of the vibration equation, and the least square method and five point sliding average method are used. The random interference signal and high frequency signal in the vibration signal are pretreated. The real modal least square iterative method is used to identify the vibration signals in frequency domain, and the experimental modal parameters of the space vibration of the pipeline are extracted. The comparison analysis is made with the ITD method and the STD method, which is identified in time domain, in order to determine the main vibration. In order to study the optimum vibration frequency of the body, in order to study the three-dimensional vibrating screen under the exciting vibration of the hydraulic pipe network, a hydraulic excitation test system is designed to simplify the vibration sieve plate to the elastic plate. The regression analysis is made on the factors affecting the amplitude of the elastic plate, and the function relation between the frequency of the frequency converter and the pressure of the system and the amplitude of the elastic plate is fitted out. The controllability of the hydraulic vibration excitation system with the elastic plate as the carrier is shown. The spatial combined vibration equation of the three-dimensional vibrating screen under the action of the hydraulic excitation is established. The vibration trajectory is simulated and synthesized, and the motion trajectory of the plane composite vibrating screen is compared. The motion characteristics of the material on the hydraulic vibration sieves are studied, and the results are revealed. Under the action of hydraulic excitation, the motion along the length direction of the vibrating screen is manifested by the vibration of multiple excitation and multiple degrees of freedom with different amplitude and frequency. It is beneficial to the vibration demand of different parts of the material on the vibrating screen, and the sieving advantage of the material is obvious. This paper, through the combination of theoretical analysis and experimental research, puts forward the active generation. The new hydraulic excitation mechanism of the hydraulic fluctuation applied to the pipe vibration control provides the theoretical basis and experimental research for the generation and control of the new hydraulic exciting mode. It reveals the controllability of the pipe vibration under the action of active hydraulic excited wave, which has important theory for deepening the theory of hydraulic vibration and the use of vibration. And practical significance.
【学位授予单位】：太原理工大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH237.6
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本文编号：1993200