本文選題：液壓激振 + 雙源液壓　； 參考：《太原理工大學(xué)》2013年博士論文

【摘要】：針對振動機械中大量使用的基于慣性激振的振動篩,其偏心塊在旋轉(zhuǎn)過程中易在非振動方向產(chǎn)生離心力的分力,從而造成振動效率低及參數(shù)不易調(diào)節(jié)等問題,本文提出了一種新的液壓激振機理,利用激波器轉(zhuǎn)閥的快速換向使管內(nèi)流體壓力、流速發(fā)生急劇變化,從而使管網(wǎng)產(chǎn)生可控的多點激振和多自由度振動的新型液壓激振方式。對液壓激振作用下流體與管道的耦合振動特性進行了仿真分析與試驗研究,實現(xiàn)了由液壓缸-激波器組成的雙源液壓激振作用下管網(wǎng)的振動控制,并對液壓激振作用下的三維振動篩進行了應(yīng)用研究。本文首先建立了液壓激振波的數(shù)學(xué)模型,采用特征線法(MOC)編程求解出了液壓激振系統(tǒng)流體的動力學(xué)特性,數(shù)值模擬了管道在液壓激振波作用下斷面激振壓力與變頻器頻率、系統(tǒng)壓力之間的關(guān)系,表明液壓激振系統(tǒng)的振動參數(shù)可通過調(diào)頻與調(diào)壓實現(xiàn)可控。在液壓激振機理的基礎(chǔ)上構(gòu)建了液壓激振試驗系統(tǒng),采用壓力變送器及數(shù)據(jù)采集卡對管道內(nèi)流體的動態(tài)特性進行了檢測,通過時域分析與頻域分析相結(jié)合的方法對流體的動力學(xué)特性進行了試驗研究,驗證了液壓激振系統(tǒng)的可控性。首次提出了由液壓缸-激波器組成的雙源液壓激振的振動機理,引入傳遞函數(shù)對系統(tǒng)各環(huán)節(jié)進行了數(shù)學(xué)描述,數(shù)值模擬了脈動流作用下液壓激振系統(tǒng)主要部件的運動學(xué)特性,揭示了由液壓缸-激波器組成的液壓激振系統(tǒng)的雙源特性。建立了液壓激振波作用下充液管道流固耦合的振動方程,采用特征線-有限元法(MOC-FEM),把管道簡化為梁模型,將特征線法計算出的流體激振壓力施加到管道的有限元節(jié)點上,在保證流體特征線節(jié)點與管道的有限元節(jié)點相重合的前提下,用Newmark法編程將流體各斷面橫向激振壓力施加到管道的有限元節(jié)點上,求得了管道橫向各斷面處及軸向的振動響應(yīng),通過FFT法獲取了幅頻特性并與試驗進行了對比分析。構(gòu)建了基于管網(wǎng)的液壓激振試驗系統(tǒng),通過試驗對比分析,確定了可進行振動利用的管網(wǎng)激振系統(tǒng)并進行了振動測試,對影響管道振幅及振動頻率的因素進行了回歸分析,擬合出了變頻器頻率和系統(tǒng)壓力與管道振幅及振動頻率的函數(shù)關(guān)系。將試驗時程曲線與數(shù)值模擬進行了對比,振動波形在振幅及振型上具有較好的吻合度。對管道固液耦合振動方程進行了拉氏變換,根據(jù)振動方程的傳遞函數(shù)得到了位移頻響函數(shù),采用最小二乘法、五點滑動平均法編程對振動信號中的隨機干擾信號及高頻信號進行了平滑預(yù)處理。采用實模態(tài)最小二乘迭代法對振動信號進行了試驗?zāi)B(tài)參數(shù)的頻域識別,提取出了管道空間振動的試驗?zāi)B(tài)參數(shù),并與時域識別的ITD法和STD法進行了對比分析,為確定主振體的最佳振動頻率提供了依據(jù)。為研究液壓管網(wǎng)激振下的三維振動篩,設(shè)計了將振動篩板簡化為彈性板的管網(wǎng)液壓激振測試系統(tǒng),對影響彈性板振幅的因素進行了回歸分析,擬合出了變頻器頻率和系統(tǒng)壓力與彈性板振幅的函數(shù)關(guān)系,揭示了以彈性板為載體的液壓激振系統(tǒng)的可控性。建立了液壓激振作用下三維振動篩的空間合振動方程,對振動軌跡進行了仿真合成,并與平面復(fù)合振動篩的運動軌跡進行了對比。研究了物料在液壓激振三維振動篩上的運動特性,揭示出在液壓激振作用下沿振動篩長度方向的運動表現(xiàn)為振幅與頻率不同的多點激振和多自由度的振動,有利于物料在振動篩上不同部位的振動需求,對物料的篩分優(yōu)勢明顯。本文通過理論分析與試驗研究相結(jié)合的方法,提出了將主動產(chǎn)生的液壓波動應(yīng)用到管道振動控制上的新的液壓激振機理,為這種新的液壓激振方式的產(chǎn)生及控制提供了理論依據(jù)與試驗研究,揭示了主動液壓激振波作用下管道振動的可控性,這對深化液壓振動理論及振動利用工程具有重要的理論與實踐意義。
[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.
【學(xué)位授予單位】：太原理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2013
【分類號】：TH237.6
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本文編號：1993200