機械設計外文翻譯-小車的動態模型和動態橋式起重機的仿真 【中文2260字】【PDF+中文WORD】
機械設計外文翻譯-小車的動態模型和動態橋式起重機的仿真?【中文2260字】【PDF+中文WORD】,中文2260字,PDF+中文WORD,機械設計,外文,翻譯,小車,動態,模型,橋式起重機,仿真,中文,2260,PDF,WORD
【中文2260字】
小車的動態模型和動態橋式起重機的仿真
摘要
根據小車的結構和工作橋式起重機的特點，本文建立了雙擺系統動態模式的車時起點。并利用亞當斯進行動力學仿真，得到懸重的偏角和鋼絲繩的橫向張力，隨時間變化，主要因素是小車的鋼絲繩長度對啟動加速度的大小有影響。當吊車開始廣泛得到運用，它實現一個真正的動態特性。
關鍵詞：橋式起重機 吊車 雙擺 動態模型 動態仿真
引言
小車起重機系統的最大特點是開始和工作時制動頻繁。在開始和突然剎車時，起重機機械系統會產生強烈的沖擊和振動。這種沖擊和振動會帶來整個系統的動態負載，使貨物擺動。越小的動態負載，貨物擺動范圍越小。所以起重機可以更穩定地工作，并具有更長的使用壽命。因此，研究小車起重機系統在啟動的動態響應和制動工況具有重要的工程意義。本文重點介紹了小車的動力學特性在啟動條件。目前，小車的動態模型在啟動條件下是單擺的動態模型，這是根據實際起吊貨物作業的小車不同而變化。在這篇文章中，雙擺動力學數學小車在啟動工況模型建立和全面的動態仿真結束考慮到小車的實際操作中，從三個繩貨物的懸浮液的長度的各方面，從小車吊鉤懸掛點的繩子長度的貨物，具有加速度的小車，并對該小車在開始的時候的效果運行條件的擺動角度進行了研究發現這是隨時間變化的橫拉的過程。
雙擺動力學小車的數學模型
橋式起重機起吊貨物的小車顯示在圖1中：
1-貨物2-掛鉤3-滑輪組4-鋼絲繩5-小車6-主梁
其中M0是商品的質量，M1是質量總和鉤子和滑輪，M2是小車的總質量，Q是電動機起動時的驅動力的轉換，L1為繩索懸掛物品的長度，L是線的長度繩子從懸掛點到鉤，a1為擺動繩與垂直方向鋼絲繩的相比，當開始a2為貨物的擺動角度與垂直相比方向開始的時候，不計空氣阻尼的影響，忽略鋼絲繩的質量，繩子的長度保持不變。不包括空氣阻尼的影響，忽略鋼絲繩的質量，繩子的長度保持不變。所以根據特性小車系統的結構和工作，小車可以實現該系統，雙擺動力學小車在開始工作的數學模型條件成立，示于圖2。
圖2 雙擺動力學數學小車在啟動工作狀態模型圖
小車的動力學方程
對于小車，在啟動過程中，X2是M2的水平方向的位移，X1是M1的水平方向的位移，X0是M0的水平方向的位移，?是摩擦阻力，建立平面直角坐標系，圖2中的M0和M1在坐標系中列如下方程：
因為α1和α2是非常小的，因此它們可以近似為：α1≈sinα1 α2≈sinα2 cosα1≈1 cosα2≈1
系統的總動能如下：
該系統的總能：
使用第二拉格朗日方程，可以得到小車的在開始工作雙擺系統的動力學方程如下：
從通過式（1）（3）我們可以看到，部分角a1和a2的主要影響因素是貨物M0，滑輪和吊鉤的質量M1，鋼絲繩的長度，懸掛物品的L1，繩子的長度掛鉤商品 L2，小車加速X2。進一步的分析表明，在這些因素中，L1，L2和X2起主要影響。
模擬與小車的分析
本文使用了一個50t/10t雙梁起重機，M5的工作層面，例如。該參數如下：該移動電機類型是YZR160M2-6，功率為8.5KW，轉速為雙速930r/min;齒輪減速器的傳動比為37.9，率鋼絲繩為10;鼓的直徑為400mm，鋼絲繩直徑為24毫米;小車的速度均勻是640毫米/秒。因為鋼絲繩的速度是10，模擬條件是，鉤可以提升5噸貨物。
首先，我們使用SolidWorks構建橋式起重機的相關三維模型，然后輸入簡化模型導入ADAMS。確定貨物的相關運動，包括鋼絲繩是由分立的柔性的組成部分組成。終于得到了橋式起重機的工作模式在虛擬三維仿真環境。如圖3所示：
圖3 臺車的模型在ADAMS中
通過計算，小車的起始時間為3.2s。仿真時間取為10s，仿真步長為200mm。因為鋼絲繩的稅率為10，使用密度有償提供方法來設定權重5t。仿真步驟和仿真分析如下：
1）L2的影響。取L1為2.5m，平均加速度為0.2m/ s2中。取L2為0.5m，1m，1.5m。從仿真結果（角的圖略），隨著L2的增加，我們可以知道α1，α2只增加很小，隨著L2的增加。所有這些影響相當于較小的尺寸，但是對α1和α2的振蕩頻率的影響很大。
2）L1的影響。取L2為0.5m，平均加速度為0.2m/ s2。取L1為2m，2.5m，3m做動態模擬。從模擬（角的數字是省略）每次增加L1。α1每次增加0.25度。α2每次分別增加0.25度和0.1度。伴隨著增長大于L2，α1和α2的振蕩頻率降低了L。
3）從影響汽車的加速的水平拉力的鋼絲繩的角度。綜合上述結論，取L1為2m，L2為0.5m做動態模擬。圖4示出在模擬條件下的轎廂速度線圖。汽車的正常運行速度是640mm/s。紅色實線示出，實現了時間的正常運行速度為3.2s，所以啟動平均加速度為0.2m/ s2，假設它為α1。藍色虛線表示，實現了時間的正常運行速度為2.5s，因此起始平均加速度為256mm/ S2，假設它為α2。
圖4 車速圖
圖5，圖6示出的角度（α1和α2）改變兩個不同的加速度（α1和α2）的示意圖。通過仿真圖形分析，汽車的起動加速度增大，并且角α1和α2也增加了。當汽車的平均加速度從200mm/ S2增大到256mm/s2，α1增加了0.5度和α2增加0.75度。從該仿真結果分析，角在汽車起步加速和增加與轎廂加速度而振蕩頻率對轎廂的加速度小的影響下有很大的影響。
α1的加速度
α2的加速度
圖5在不同的加速度下改變α1
α1的加速度
α2的加速度
圖6在不同的加速度下改變α2
圖7顯示在不同加速度下鋼絲繩橫向張力的變化規律。從仿真結果中，我們可以知道，隨著啟動加速度的增加，鋼絲橫向繩張力增加了約750N。在啟動過程中，這是具有明顯增加的水平移動荷載。因為這個擺是由動態負載帶來的，在正常的速度下小車出現小幅度波動。
圖7 橫向鋼絲繩張力
結論
研究了擺動角度和動態特性具有重要意義，提高了起重機的工作效率和穩定性。本文采用了當小車啟動時用ADAMS模擬擺動角度以及重物的動態特性。從仿真中，首先我們可以知道，L1和L2的大小對擺動頻率有較大影響，它們具有更大的長度，更大的擺動角度。其次，擺動角的大小和水平動態負載對小車的加速度具有更大的影響，并且隨著增加小車的加速度二者將不斷增加。
The Trolleys Dynamic Model and Dynamic Simulation of the Bridge Crane Xiangdong Li,Xucheng Yuan,Chao Zhou,Xu Chen Jiangsu Institute of Special Equipment Safety Supervision and Inspection Nanjing,China Shuishui Li,Yuanxun Fan Nanjing University of Science and Technology Nanjing,China AbstractAccording to the trolleys structure and working characteristics of bridge crane,this paper has established the double pendulum dynamic system mode when the trolley is starting.And it also use ADAMS to proceed this dynamic simulation,then get the hanging heavys partial angular and the wire ropes horizontal tension that changes with time of history,find the main factor-the length of the wire rope and trolleys start-up acceleration that influence the angles size.It realizes a true dynamic characteristic when the trolley is starting.Keywords-bridge crane;trolley;double pendulum;dynamic model;dynamic simulation I.INTRODUCTIONThe biggest characteristic of trolley crane system is starting and braking frequently when working.In the moment of starting and braking frequently and suddenly,the crane mechanical system will have a strong impact and vibration.This shock and vibration will bring the whole system the dynamic load,and make goods swing.The smaller the dynamic load is,the smaller the range of goods swing is.So the crane can work more stably and have longer life.Therefore,the study of the dynamic response of trolley crane system in the starting and braking condition has important engineering significance.This paper focuses on the dynamics characteristic of the trolley in start conditions.At present,the dynamic model of the trolley in start condition is single pendulum dynamic model,which is different from the actual lifting goods operation of the trolley.In this article,the double pendulum dynamics mathematical model of the trolley in the start working condition is established and the dynamic simulation is finished with fully considered the actual operation of the trolley,From three aspects of the length of rope for the suspension of goods,the length of rope from trolley hook suspension point to goods,the acceleration of the trolley,the effect of the trolleys start running condition to the swing angle is researched and the process of the horizontal pull which is changed with time is found.II.THE DOUBLE PENDULUM DYNAMICS MATHEMATICAL MODEL OF THETROLLEYThe trolley of the bridge crane lifting with goods is shown in figure 1:Figure 1 trolley 1-goods 2-hook 3-pulley block 4-wire rope 5-trolley of bridge crane 6-main girder Where 0mis the quality of goods,1mis the quality sums of the hook and the pulley,2mis the trolleys total mass,Q is the driving force conversion of the motor when starting,1Listhe length of rope for hanging goods,2L is the length of wire rope from the suspension point to the hook,1?is the swing angle of wire rope compared with vertical direction when starting,2?the swing angle of goods compared with vertical direction when starting,Excluding the effects of air damping,ignoring the quality of steel wire rope,and the rope length remains unchanged.So according to the characteristics of the trolley systems structure and work,trolley can travel under the and of the system,the double pendulum dynamics mathematical model of the trolley in the start working conditions is established which is shown in Figure 2.?Figure 2 the double pendulum dynamics mathematical model figure of the trolley in the start working condition Quality and Technical Supervision Bureau of Jiangsu,KJ103708_ 978-1-61284-441-1/11/$26.00 2011 IEEE 216III.DYNAMIC EQUATION OF THE TROLLEYFor the trolley,where 2x is the displacement of 2minstart-up process,1xis the horizontal displacement of 1min the start-up process,0 xis the horizontal displacement of 0min the start-up process,f is the friction resistance during the start-up process.Establish plane Cartesian coordinate system,as shown in figure 2 is 1mand0m position respectively in the coordinate system are as follows:1211111sincosxxLyL?And 02112201122sinsincoscosxxLLyLL?Because1?and 2?are very small,so it can be approximated into:112212sin,sin,cos1,cos1?The total kinetic energy of system is as follows:222212211100222022121212222211021211122222121222111)222 11)(222 1)22 22Em xm xymxym xm xL xLm xL xLL xL LL?The systems total potential is:(1 cos)(coscos)21110121122Em gLm g LLLL?Using the second Lagrange equation,can get the trolleys starting work double pendulum dynamics system equation as follows:221121110120110122111011 0m L xm Lm L xm Lm L Lm gLm gL?1?221211102011022m xm xm Lm xm Lm LQf?2?202212122022()0m L xL LLm gL?3?From type(1)through(3)we can see that the major influence factors of the partial angle1?and 2?is the quality of the goods0m,the quality of pulley and hook1m,wire ropes length of suspension goods1L,ropes length from hooks to goods2L,acceleration of trolley2x?.Further analysis shows that in these factors,1L,2Land 2x?plays a main influence.IV.SIMULATION AND ANALYSIS OF TROLLEYThe paper has used a 50t/10t double girder crane with M5 working level for example.The parameters are as follows:The moving motor type is YZR160M2-6,power is 8.5KW,rotate speed is 930r/min;Transmission ratio of gear reducer is 37.9;Rate of wire rope is 10;Diameter of drum is 400mm;Diameter of wire rope is 24 mm;The trolleys uniform speed is 640mm/s.Because of rate of wire rope is 10,simulation conditions is that hook takes full lifting 5t goods.Firstly we use SOLIDWORKS to build the bridge cranes related 3d model,and then input the simplified model into ADAMS.Define related movement of goods,including the wire rope which is composed by discrete flexible components.Finally get the bridge cranes working model in virtual 3d simulation environment.Figure 3 shows:Figure 3 trolleys model in ADAMS Through calculation,the trolleys starting time is 3.2 seconds.The simulation time is taken as 10s,simulation step length is 200.Because rate of wire rope is 10,use available compensational method of density to set the weight for 5t.Simulation steps and the simulation analysis are as follows:1)The influence of2L.Take 1L for 2.5 m,the average acceleration is 0.22/m s.Take 2L for 0.5m,1m,1.5m.From the simulation results(the angles figure is omitted),we can know1?,2?all increase only tiny along with the increase of2L.The size of them all influenced relatively small,but the oscillation frequency of 1?and2?are influenced larger.2)The influence of1L.Take 2L for 0.5m,the average acceleration is 0.22/m s.Take 1L for 2m?2.5m?3m to do dynamic simulation.From the simulation(the angles figure is 217omitted)that with the twice increasing of1L.1?every time increased 0.25?.2?every time increased 0.25?and 0.1?respectively.Growth is greater than their influence about2L.And the oscillation frequency of 1?and 2?also decreases with the increasing of 2L.3?The influence of angular and the horizontal tension wire rope from car acceleration.Comprehensive the foregoing conclusion,take 1L for 2m,2L for 0.5m for dynamic simulation.Figure 4 shows the car velocity diagram in simulation conditions.The normal operation speed of the car is 640mm/s.The red solid line shows that achieving the normal operation speed of time is 3.2s,so the starting average acceleration is 0.22/m s,assuming it as 1a.Blue dashed said that achieving the normal operation speed of time is 2.5s,so the starting average acceleration is 2562/mm s,assuming it as 2a.Figure 4 Vehicle speed diagram Figure 5,figure 6 shows the angle(1?and 2?)changing diagram of the car in the two different acceleration(1a and 2a).By the simulation graphics analysis,the start-up acceleration of car increased,and the angular 1?and 2?also increased.When the car average acceleration from 2002/mm s increases to 2562/mm s,Angular1?increased 0.5?and angular 2?increased 0.75?.From this simulation result,angular has great influence on the car start-up acceleration and increases with the increasing of car acceleration while oscillation frequency has small influence on car acceleration.Acceleration is 1a Acceleration is 2aFigure 5 changing rules of 1?in different acceleration Acceleration is 1a Acceleration is 2aFigure 6 changing rules of 2?in different acceleration Figure 7 shows the horizontal tensions changing rule of wire rope in different acceleration.From the result of simulation,we can know that the horizontal tension of wire rope has increased about 750N along with the increase of start-up acceleration.It also has obviously increased the horizontal moving load of the start-up process.And because of this swing which is brought by the dynamic load,the normal speed of the trolley appears slight fluctuations.Figure 7 the horizontal tension of wire rope V.CONCLUSIONResearch the swinging Angle and dynamic characteristics of the heavy has great significance to improve the cranes working efficiency and steadiness.The paper has used ADAMS to simulate the swinging Angle and dynamic characteristics of the heavy when the trolley is starting.From the simulation,firstly we can know that the size of 1L and 2Lhas bigger influence to the swinging frequencies.The bigger length they are,the bigger swinging angle it is.Secondly,the trolleys acceleration has bigger influence to the size of swinging angle and the horizontal dynamic load.And both of them will be increased while the increasing of the trolleys acceleration.REFERENCES1Raymond Manning,Jeffrey Clement,Dooroo Kim,William Singhose,“Dynamics and Control of Bridge Cranes Transporting Distributed-Mass Payloads,”Journal of Dynamic Systems,Measurement,and Control,vol 132,pp.18,January 2010 2Dooroo Kim,William Singhose,“Performance studies of human operators driving double-pendulum bridge cranes,”Control Engineering Practice 18(2010),pp.567576 3Zongwu Hu,Yisong Yan,“crane dynamics,”Machinery industry press,1988 4Zhiweng Zhang,Heqian Yu,Jingnuo Wang,“Crane design manual,”China railway publishing house,1998 5Zenggang Li,“ADAMS introductory explanation and examples,”Defense industry press,2006 6Zeqiang Zhang,Wenming Cheng,“Bridge type crane heavy dof angular model and simulation,”Southwest jiaotong university journal,2006,41(6)pp.696699 218
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