外文翻譯--起重機介紹

1、<p><b>　　附 錄</b></p><p><b>　　外文文獻原文：</b></p><p>　　The Introduction of cranes</p><p>　　A crane is defined as a mechanism for lifting and lowering load

2、s with a hoisting mechanism Shapiro, 1991. Cranes are the most useful and versatile piece of equipment on a vast majority of construction projects. They vary widely in configuration, capacity, mode of operation, intensit

3、y of utilization and cost. On a large project, a contractor may have an assortment of cranes for different purposes. Small mobile hydraulic cranes may be used for unloading materials from trucks and for small concrete<

4、;/p><p>　　On many construction sites a crane is needed to lift loads such as concrete skips, reinforcement, and formwork. As the lifting needs of the construction industry have increased and diversified, a larg

5、e number of general and special purpose cranes have been designed and manufactured. These cranes fall into two categories, those employed in industry and those employed in construction. The most common types of cranes us

6、ed in construction are mobile, tower, and derrick cranes.</p><p>　　Mobile cranes</p><p>　　A mobile crane is a crane capable of moving under its own power without being restricted to predetermine

7、d travel. Mobility is provided by mounting or integrating the crane with trucks or all terrain carriers or rough terrain carriers or by providing crawlers. Truck-mounted cranes have the advantage of being able to move un

8、der their own power to the construction site. Additionally, mobile cranes can move about the site, and are often able to do the work of several stationary units.</p><p>　　Mobile cranes are used for loading,

9、mounting, carrying large loads and for work performed in the presence of obstacles of various kinds such as power lines and similar technological installations. The essential difficulty is here the swinging of the payloa

10、d which occurs during working motion and also after the work is completed. This applies particularly to the slewing motion of the crane chassis, for which relatively large angular accelerations and negative accelerations

11、 of the chassis are char</p><p>　　Modern mobile cranes include the drive and the control systems. Control systems send the feedback signals from the mechanical structure to the drive systems. In general, the

12、y are closed chain mechanisms with flexible members [1].</p><p>　　Rotation, load and boom hoisting are fundamental motions the mobile crane. During transfer of the load as well as at the end of the motion pr

13、ocess, the motor drive forces, the structure inertia forces, the wind forces and the load inertia forces can result in substantial, undesired oscillations in crane. The structure inertia forces and the load inertia force

14、s can be evaluated with numerical methods, such as the finite element method. However, the drive forces are difficult to describe. During s</p><p>　　Modern mobile cranes that have been built till today have

15、oft a maximal lifting capacity of 3000 tons and incorporate long booms. Crane structure and drive system must be safe, functionary and as light as possible. For economic and time reasons it is impossible to build prototy

16、pes for great cranes. Therefore, it is desirable to determinate the crane dynamic responses with the theoretical calculation.</p><p>　　Several published articles on the dynamic responses of mobile crane are

17、available in the open literature. In the mid-seventies Peeken et al. [4] have studied the dynamic forces of a mobile crane during rotation of the boom, using very few degrees of freedom for the dynamic equations and very

18、 simply spring-mass system for the crane structure. Later Maczynski et al. [5] studied the load swing of a mobile crane with a four mass-model for the crane structure. Posiadala et al. [6] have researched the</p>

19、<p>　　A detailed and accurate model of a mobile crane can be achieved with the finite element method. Using non-linear finite element theory Gunthner and Kleeberger [9] studied the dynamic responses of lattice mobil

20、e cranes. About 2754 beam elements and 80 truss elements were used for modeling of the lattice-boom structure. On this basis a efficient software for mobile crane calculation––NODYA has been developed. However, the influ

21、ences of the drive systems must be determined by measuring on hoisting </p><p>　　Studies on the problem of control for the dynamic response of rotary crane are also available. Sato et al. [14], derived a con

22、trol law so that the transfer a load to a desired position will take place that at the end of the transfer of the swing of the load decays as soon as possible. Gustafsson [15] described a feedback control system for a ro

23、tary crane to move a cargo without oscillations and correctly align the cargo at the final position. However, only rigid bodies and elastic joint between </p><p>　　To improve this situation, a new method for

24、 dynamic calculation of mobile cranes will be presented in this paper. In this method, the flexible multibody model of the steel structure will be coupled with the model of the drive systems. In that way the elastic defo

25、rmation, the rigid body motion of the structure and the dynamic behavior of the drive system can be determined with one integrated model. In this paper this method will be called ‘‘complete dynamic calculation for driven

26、 “mechanism”.</p><p>　　On the basis of flexible multibody theory and the Lagrangian equations, the system equations for complete dynamic calculation will be established. The drive- and control system will be

27、 described as differential equations. The complete system leads to a non-linear system of differential equations. The calculation method has been realized for a hydraulic mobile crane. In addition to the structural eleme

28、nts, the mathematical modeling of hydraulic drive- and control systems is decried. The simulatio</p><p>　　Tower cranes</p><p>　　The tower crane is a crane with a fixed vertical mast that is topp

29、ed by a rotating boom and equipped with a winch for hoisting and lowering loads (Dickie, 990). Tower cranes are designed for situations which require operation in congested areas. Congestion may arise from the nature of

30、the site or from the nature of the construction project. There is no limitation to the height of a high-rise building that can be constructed with a tower crane. The very high line speeds, up to 304.8 mrmin, availa</p

31、><p>　　The tower cranes are more economical only for longer term construction operations and higher lifting frequencies. This is because of the fairly extensive planning needed for installation, together with t

32、he transportation, erection and dismantling costs.</p><p>　　3. Derrick cranes</p><p>　　A derrick is a device for raising, lowering, and/or moving loads laterally. The simplest form of the derric

33、k is called a Chicago boom and is usually installed by being mounted to building columns or frames during or after construction (Shapiro and Shapiro, 1991).This derrick arrangement. (i.e., Chicago boom) becomes a guy der

34、rick when it is mounted to a mast and a stiff leg derrick when it is fixed to a frame.</p><p>　　The selection of cranes is a central element of the life cycle of the project. Cranes must be selected to satis

35、fy the requirements of the job. An appropriately selected crane contributes to the efficiency, timeliness, and profitability of the project. If the correct crane selection and configuration is not made, cost and safety i

36、mplications might be created (Hanna, 1994). Decision to select a particular crane depends on many input parameters such as site conditions, cost, safety, and their varia</p><p>　　Cranes are not merely the la

37、rgest, the most conspicuous, and the most representative equipment of construction sites but also, at various stages of the project, a real “bottleneck” that slows the pace of the construction process. Although the crane

38、 can be found standing idle in many instances, yet once it is involved in a particular task ,it becomes an indispensable link in the activity chain, forcing at least two crews(in the loading and the unloading zones) to w

39、ait for the service. As analyzed</p><p>　　The following sections describe various facets of crane automation: First, the necessary components and their technical characteristics are reviewed, along with some

40、 selection criteria. These are followed by installation and integration of the new components into an existing crane. Next, the Man –Machine –Interface (MMI) is presented with the different modes of operation it provides

41、. Finally, the highlights of a set of controlled tests are reported followed by conclusions and recommendations. Ma</p><p><b>　　外文文獻中文翻譯：</b></p><p><b>　　起重機介紹</b></p&

42、gt;<p>　　起重機是用來舉升機構、抬起或放下貨物的器械。在大多數的建設工程中，起重機是最有用、功能最多的器械。它們因結構、容量、操作模式、使用強度和費用的不同而不同。在一個大的工程項目上，一個承包商可以因為不同的利用目的而使用多種起重機。小的液壓移動式起重機可以用來從卡車上卸下材料，處理小而具體的物體的安置，然而較大的爬式或塔式起重機可以用來豎立并移動框架，安置加強的鋼鐵，放置混凝土，豎起鋼筋結構和預制混凝土橫梁。&

43、lt;/p><p>　　在一些建設地點，一臺起重機是用來提升重物的，例如：混凝土的裝料車、加強部分和模殼。隨著建筑行業(yè)的提升要求不斷增加并且變化多樣，大量的具有綜合的和特殊性能的起重機被設計和制造出來。這些起重機被分成兩類：工業(yè)用起重機和建筑用起重機。用于建筑業(yè)的最普通型式的起重機是移動式、塔式和架式起重機。</p><p><b>　　1. 移動式起重機</b><

44、/p><p>　　一臺移動式起重機是一個不被局限于預先確定的軌道，在自身動力的驅動下具有運動能力的起重機。將起重機與卡車，甚至所有地帶的運輸工具甚至粗糙地帶的運輸工具，更甚至借助于所提供的爬行工具，起重機的就有運動的可能。車載起重機具有在它們自己的動力驅動下能夠移動至建筑地點中的任何地方的優(yōu)勢。此外，移動式起重機可以在場所內移動，經常能夠處理與提升一些靜止部件的工作。</p><p>　　移動

45、式起重機用來裝載、安裝、搬運大負荷，也常用于在各種各樣的障礙中，例如：力量線和相似的科技安裝。在這兒必不可少的困難是當工作過程中和工作完成之后有效載荷的擺動，相關的大的角速度和底座的負的速度是其特有的。慣性力，伴著離心力和科里奧利力引起載物像一個球形鐘擺一樣旋轉。當工作行為結束時，對同時用于將貨物輸送到限定地點的起重機的旋轉動作進行適當的限制，在模型中起著很重要的作用。</p><p>　　現代的移動式起重機包括

46、驅動和控制系統(tǒng)?？刂葡到y(tǒng)把來自機械結構的反饋信號傳送到驅動系統(tǒng)，大體上，它們是由柔性元件組成的閉鏈機械系。</p><p>　　旋轉、負荷和提升是移動式起重機的基礎動作，在傳送重物的過程中與運作過程一樣，馬達的驅動力、結構內應力、風力和貨物的內力可以導致起重機產生一定的不希望得到的搖晃。結構內應力和貨物內應力可以用數學方法進行估價，例如有限元的方法。無論怎樣，驅動力是很難描述的。在起動和制動的過程中，驅動系統(tǒng)的外

47、力起伏變化很大。為了減小起動和制動中速度的變化，可控制的馬達必須產生可變化的力矩，來影響起重機的運作。</p><p>　　現代的移動式起重機直到今天還在鑄造，常常有3000噸的舉重能力，而且經久不衰。起重機的結構和傳動系統(tǒng)必須是安全、有效和盡量輕巧的。因為經濟和時間的原因，對于大的起重機不可能建造出其原型，所以，人們希望利用理論上的計算來確定起重機的電動反應。</p><p>　　在開放

48、的文化中，一些反映移動式起重機動態(tài)影響的已發(fā)表文章是可以找到的。其中70歲的Peeken通過在動態(tài)方程中利用很少的自由度，并在起重機結構中利用非常簡單的彈簧阻尼系統(tǒng)，研究了在懸臂旋轉中一臺移動式起重機的動態(tài)力學。之后，Maczynski研究了起重結構上有四塊模型的移動式起重機的載荷搖擺問題。Posiadala考慮到旋轉、裝載和載荷提升的變化而研究了被提升的載荷的運動。無論怎樣，只有運動學被研究了。稍后，相同的作家調查了在載荷運行中的支持

49、系統(tǒng)的彈性影響。最近，Kilicaslan利用柔性綜合動態(tài)方法研究了移動式起重機的特性。Towarek把研究彈性基壤的影響集中在懸臂式起重機的動態(tài)穩(wěn)定性上。在這些研究中，通過利用所謂帶有假定速度和加速度的運動力學的方法，驅動力無論怎樣都有所出現。在實踐中，這種假想無法和運行中的起動和制動相符合。</p><p>　　利用有限元的方法，一個詳細且正確的移動式起重機的模型是可以實現的。利用非線性有限元理論，Gunth

50、ner 和 Kleeberger研究了移動式起重機的動態(tài)影響，在網格結構中，大約2754個光線元素和80個構架元素被用到。在此基礎上，一個有效的關于移動式起重機計算的有效軟件NODYA被發(fā)明出來。無論如何，通過衡量載荷的提升量或起重機的旋轉，驅動系統(tǒng)的影響必須要考慮到。這對于起重機多種運動的計算機模擬來說，既不很有效也不方便。</p><p>　　對于旋轉起重機動態(tài)影響的控制的問題研究是有效的。Sato讓那個在載

51、荷搖擺轉換末尾可將重物傳遞到所渴望的位置的控制理論盡快的衰退。Gustafsson為了移動貨物時沒有振動并且正確地在最后位置排列貨物，描述了一個旋轉起重機的反饋控制系統(tǒng)。然而，在研究中，只有在懸臂和絞點中的堅硬的固體和彈性節(jié)點被考慮到了。因為這個原因，所以起重機的動態(tài)影響是廣泛存在的。</p><p>　　為了改變這種狀況，關于移動式起重機的動態(tài)計算的一種新的方法將會出現。在這種方法中，鋼鐵結構的彈性綜合模型將會

52、同驅動系統(tǒng)的模型一起出現。在那種方法下，用一個獨立的模型，就可以解決關于彈性破壞、結構的固體運動和驅動系統(tǒng)的動態(tài)行為問題。這種方法被稱為驅動機構的全動態(tài)計算。</p><p>　　在彈性綜合體理論和方程的基礎上，全動態(tài)計算的系統(tǒng)方程將被確定下來。驅動和控制系統(tǒng)將用不同的方程來描述。整個系統(tǒng)生成一個不同方程的非線性系統(tǒng)。在一個液壓移動式起重機上這種計算方法得以實現了。為了補充結構單元，液壓驅動和控制系統(tǒng)的數學模型將

53、被刪除。多種工作狀況的起重機旋轉的模擬將被啟用。結果，一個不光為起重機結構，更為驅動系統(tǒng)的更加詳細的表達將會實現。在這些模型計算結果的基礎上，起重機起動和制動過程中的加速度和速度影響將會被討論。</p><p><b>　　2. 塔式起重機</b></p><p>　　塔式起重機是一種在固定垂直桅桿頂端裝有旋轉桿的起重機，并被裝備了絞盤，用以舉升和降下重物。塔式起重機

54、是為滿足在擁擠密集地點作業(yè)的要求而設計的。擁擠可能是由于地理位置的自然狀況或者是因為建筑工程的特點。對于可以借助塔式起重機來建筑實施的高層樓房來說，其高度是沒有限制的。非常高的線速度，高達304.8米/分鐘，利用在一些具體模型上就可以在任何高度產生高的生產效率。它們提供了一個相當大的水平作業(yè)半徑，在地面上卻只需要一個很小的工作場地。一些機器還可以在72.4千米/時的速度下旋轉，這遠遠超過了移動式起重機的旋轉速度。</p>

55、<p>　　塔式起重機只對較長工作周期的建設運行和高的提升頻率工程來說更經濟，這是由于為安置而需要相當廣闊的規(guī)劃布置，再加上運輸、建造和拆除設備的費用。</p><p><b>　　3. 架式起重機</b></p><p>　　架式起重機是一種為提升、降下和（或）橫向移動貨物的裝置。架式起重機最簡單的形式叫做芝加哥桿，經常在建設過程中或建設過后被安放在建筑物

56、的柱子或框架上。當架式起重機被安放在桅桿上，或被固定在框架上，這種架式起重機的處理方式就變成了繩索型架式起重機和硬桿型架式起重機。</p><p>　　起重機的選擇是工程項目生命流程的中心環(huán)節(jié)。起重機必須選來滿足工作的要求。一個選擇適當的起重機對提高工程效率、縮短工作時間、增加工程收益有幫助。如果沒有實現起重機的正確選擇和構建，那么可能會產生費用增加，并牽連到安全問題。選擇一個特殊起重機的決定依賴于許多輸入參數，

57、例如：位置條件、費用、安全及它們的易變性，這些參數中很多是定性的，而且在這些術語中所暗示的主觀判斷不可以直接地被吸收到古典的決策程序中?，F在借助于模糊邏輯方法，選擇起重機的一種方法可以實現。</p><p>　　在建筑場所，起重機不僅僅是最大、最引人注意、最具有代表性的裝備，而且在工程的許多不同階段，是一個使工程進度放慢的真正障礙。雖然在遠處看去，你可能發(fā)現起重機很幽閑地站在那里，但是一旦它進入特殊的工作過程中，

58、它將在工作鏈中成為不可缺少的環(huán)節(jié)，促使至少兩個員工等候供應。正如前面的分析，使計算機自動化來達到更高的產量，更好的經濟效益和更安全的運作是可能的。把重點放在將現成的起重機變?yōu)橐粋€大的半自動操作者的技術方面是很必要的。借助附在起重機上的主要外在裝置，它變得具有學習、記憶、獨立的從計劃之前的目標或通過預先知道的路徑產生自動反饋的能力。</p><p>　　下面部分簡要描述起重機自動化的多種方面：首先，與一些選擇條件一

59、起，考察了必要成分和它們的技術性能，接下來是把這些新的元件安置并組合成一個實實在在的起重機。其次，人機界面因它提供的不同運行狀態(tài)而呈現。最終，結論和介紹尾隨一系列控制結果中的最重要的部分而產生。人工和自動運作過程的對比：塔式起重機的三個主要自由度在圖中描述出來，在一些情況下，起重機被安放在軌道上，這就提供了四個自由度，但在其他情況下，塔是可伸縮的，起重機的臂可以升到一個傾斜的角度。雖然他們的位置必須輸入控制系統(tǒng)，但因為這些附加的自由度在