外文翻譯--塔機(jī)靜剛度控制值及計(jì)算方法研究-

1、<p><b>　　附錄</b></p><p><b>　　英文原文</b></p><p>　　Calculation method and control value of static stiffness of tower crane</p><p>　　Lanfeng Yu*</p>&l

2、t;p>　　Research Institute of Mechanical Engineering, Southwest JiaoTong University, Chengdu, Sichuan, 610031, P. R. China(Manuscript Received August 31, 2006; Revised November 30, 2007; Accepted December 13, 2007)</

3、p><p><b>　　Abstract</b></p><p>　　The static stiffness of tower cranes is studied by using the proposed formulations and finite element method in this paper. A reasonable control value b

4、ased on theoretical calculation and finite element method is obtained and verified via collected field data. The results by finite element method are compared with the collected field data and that by the proposed formul

5、a. Corresponding to theoretical formulations and field data, it is found that the results by finite element method are closer to</p><p>　　Keywords: Tower crane; Static stiffness; Control value; Static displa

6、cement</p><p>　　1. Introduction</p><p>　　Sagirli, Bococlu and Omurlu (2003) realized the simulation of a rotary telescopic crane by utilizing an experimental actual system for geometrical and dy

7、namical parameters [1]. With the intention of comparing the real system and the model and of verifying the sufficiency of the model accuracy, various scenarios were defined corresponding to different loading and operatin

8、g conditions. Of the scenarios defined, impulse response, time response and static response are used to experimentally gather s</p><p>　　For static stiffness of a tower crane, the requirements of GB 3811-198

9、3 “Design rules for cranes” and GB/T 13752-1992 “Design rules for tower cranes” of China are as follows. “Under the rated load, the horizontal static displacement of the tower crane body △x at the connection place with t

10、he jib (or at the place of rotary column with the jib) should be no larger than H/100. In which H is the vertical distance of the tower body of the rail-mounted tower crane from the jib connection place to the </p>

11、<p>　　In this paper a special research on the static stiffness of tower cranes was carried out aimed at relieving the over-strict control on the static stiffness (△x H/100) in the rules above, so as to meet the r

12、equirement for revising GB/T 3811-1983 “Design rules for cranes”. </p><p>　　The remainder of this paper is organized as follows. Section 2 gives the suggested control value of static stiffness of a tower cra

13、ne. Section 3 verifies the static stiffness control value. Theoretical calculation method of static displacement of the tower body corresponding to the static stiffness control value is provided in Section 4. Section 5 c

14、ompares various methods for calculation of static displacement with the actually measured values. A brief conclusion is given in Section 6.</p><p>　　2. The suggested control value of static stiffnessof tower

15、 crane</p><p>　　Because of the wide use of high-strength steel, it is not difficult to meet the structural strength and stability.Requirements on structural stiffness are becoming a dominant factor restricti

16、ng tower crane development of towards the lightweight. The revised control value of static stiffness of tower crane should not only meet requirements of the current product development, but also should be suitable for fu

17、ture development. Based on the actual situation in China to ensure tower crane quality, s</p><p>　　Fig. 1. Schematic diagram of static displacement of the tower crane.</p><p>　　On the basis of a

18、 large number of investigations and visits to tower crane manufacturers and users, Yu, Wang, Zheng, and Wang proposed the recommended the control value of the tower crane static stiffness and the corresponding inspection

19、 method, i.e., taking the hinge-connection point of the jib end under noload condition (at this moment there is an absolute backward displacement of the jib end hingeconnection point in relation to the theoretic centerli

20、ne of the non-deformed tower body as shown </p><p>　　According to opinion of the experts of “Appraisal & evaluation meeting on special research project Revision of Rules on Crane Design,” Yu, Wang, Zheng

21、, and Wang recommended that the static stiffness control val ue is a proper limit value meeting the voice of the tower crane industry for revising and widening the △x limit value [12]. Moreover, this method is convenient

22、 for inspection. However, in order to be consistent with the coefficient value specified in international standard, it is recommen</p><p>　　Widening the static stiffness control value (1.34H/ 100) of the tow

23、er crane can reduce the tower crane production cost, so that the tower crane can develop towards lightweight in favor of the technical progress of this industry.</p><p>　　3. Verification of the static stiffn

24、ess controlvalue</p><p>　　In order to make the revised static stiffness control value of the tower crane really reflect the current actual situation of the static stiffness, a special research group carried

25、out measurements of static stiffness of 20 types of representative tower cranes which are within the period of their lifespan (see Table 1). The measurement results have shown that if measured according to the current me

26、asurement method, only one type of tower crane (sequence no. 5) can meet the static stiffness contr</p><p>　　It should be explained that all these 20 types of tower cranes are in excellent working condition.

27、</p><p>　　Table 1. The actually measured static stiffness control value and the original control value of 20 types of tower cranes.</p><p>　　4. Theoretical calculation method of static displacem

28、ent of the tower body corresponding to the static stiffness control value</p><p>　　The static displacement calculation methods include the traditional mechanics method or finite element methods. The calculat

29、ion model of the traditional mechanics method can be divided into mechanics model of continuum pressed-bending member and lattice-type frame mechanics model. The first one is simple and practical, while the second one is

30、 more accurate but the calculation is more complicated.</p><p>　　4.1 Theoretical model for continuum pressed-bending</p><p>　　According to the mechanics model of continuum pressed-bending member

31、 shown in Fig. 2, it is possible to obtain the theoretical calculation value corresponding to the static displacement measurement value described in this paper. According to the measurement method described in this paper

32、, the bending moment caused by the self-load of the tower crane under no-load and loaded conditions can be balanced heoretically. Besides, the wind load and other horizontal loads are not considered during measur</p&g

33、t;<p><b>　　(1)</b></p><p>　　Finding the solution of the above equation, we can obtain a precise calculation method of static displacement of the crane body top point:</p><p>&

34、lt;b>　　(2)</b></p><p><b>　　Where</b></p><p><b>　　(3)</b></p><p>　　where N is all the vertical force above the hingeconnection point of the crane bod

35、y and the jib under the rated load (including the converted force of the crane body at this place; the conversion method is referred to in attachment G of GB/T 13752 – 1992).M is bending moment caused by the hoisting loa

36、d,M=QR (where Q is the rated hoisting load, and R is the working amplitude corresponding to Q).</p><p>　　Fig. 2. Mechanical model of static displacement of the towercrane.</p><p>　　The above equ

37、ation can be also converted as follows.From the Euler critical load of the pressed column,</p><p><b>　　(4)</b></p><p>　　For the cantilever pressed column:=2，</p><p>　　th

38、erefore （5）</p><p>　　Expand the triangle function sec u into power series</p><p><b>　　(6)</b></p><p>　　Then Eq. (2) can be simplified into</p>&l

39、t;p>　　Defining the proximity value f as f1,</p><p><b>　　(8)</b></p><p>　　whereM is horizontal displacement of the connection place between the tower body and the jib caused by the

40、 bending moment M of the rated hoisting load to the centerline of the tower body</p><p><b>　　(9)</b></p><p>　　andis deflection amplification factor considering influence of axial for

41、ce.</p><p>　　4.2 Finite element model</p><p>　　Fig. 3. Finite element model of tower crane.</p><p>　　It is possible for the tower crane to be modeled by the finite element method. T

42、he finite element model is based on a simplification of the geometry of the tower crane structure. As a numerical method, the result from the finite element method is also approximate. The model of the tower crane is bro

43、ken into many elements (as shown in Fig. 3). There are three types of elements in this model of tower crane: the beam, bar and beam-spar element. The bow pole is modeled by using beam element. The pau</p><p>

44、;　　The material property and load condition is the same as the above section. The dimension of the tower crane is also identical with that in the above formulations.</p><p>　　5. Comparison of various methods

45、 for calculation of static displacement with actually measured values</p><p>　　To understand the error value between different calculation methods and the accurate measure, the results of analytical expressi

46、ons (2) and (8) are compared to the numerical results. Numerical analysis was carried out by software ANSYS. Meanwhile the compared experiment data is the static displacements of the first five types of the tower cranes.

47、</p><p>　　Comparison of the obtained static displacement values of the three calculating methods f1, f2, f3 (calculation values of finite element methods) with the actually measured values is shown in Table

48、2.</p><p>　　Table 2. Comparison of maximum static displacement of the tower body f1, f2, f3 and the actually measured values.</p><p>　　It can be seen from Table 2 that the error of the static di

49、splacement calculation values obtained from pressure-bending column mechanics model of the actual body according to Eqs. (2) and (8) is less than 12%. However, the error of finite element methods calculation values is le

50、ss than 10%. The reason is that the pressure-bending column mechanics model of the continuum mainly considers the stiffness of the chord members and does not consider the web members and its arrangement. Meanwhile, the s

51、t</p><p>　　the proximity calculation value f1 and the precise value f calculated under a similar mechanics model,while the error does not exceed 1%. Therefore, when calculating the maximum static displacemen

52、t of thetower body according to the mechanics model, it is reasonable to use Eq. (2) or Eq. (8).</p><p>　　The calculation method of the maximum horizonta lstatic displacement value of the relative theoretic

53、centerline of the tower body in actual work is referred to [12]. Besides vertical load, it is necessary to consider the bending moment caused by the self-weight and the lifting load. The wind load is distributed along th

54、e tower body, because the wind force, changing amplitude and rotation plays the role of brake, and the rotating centrifugal force causes concentrated horizontal force on the end p</p><p>　　6. Conclusions<

55、/p><p>　　Based on the analysis of the static stiffness filed data collected from many tower cranes which are in good working condition, if the static stiffness control value is specified to be H/100 (as require

56、d in GB 3811-1983 “Design rules for cranes” and GB/T 13752–1992 “Design rules for tower cranes”) only 5% of the investigated tower cranes can meet this requirement. If the control value of 1.34H/100 as suggested in this

57、paper is used, 75% of the investigated tower cranes can meet this requirement. </p><p>　　The simplified formula proposed in this paper and the Finite Element method are used to calculate the static stiffness

58、 of several types of tower cranes. The results show that the finite element method is more accurate. However, the simplified formulas in Eq. (2) or Eq. (8) provide a simpler and easier approach.Future work is necessary t

59、o study the dynamic response of tower cranes induced by different kinds of payloads, such as the job of Ju [13] and Chin [14].</p><p><b>　　中文翻譯</b></p><p>　　塔機(jī)靜剛度控制值及計(jì)算方法研究</p>

60、<p><b>　　于蘭峰</b></p><p>　　西南交通大學(xué)機(jī)械工程研究所，中國(guó)，四川，成都 610031</p><p>　　【摘要】在本文中對(duì)塔式起重機(jī)靜剛度的研究通過(guò)運(yùn)用被提出的公式法和有限元法。合理控制值是建立在理論計(jì)算和有限元方法在得到通過(guò)對(duì)現(xiàn)場(chǎng)數(shù)據(jù)的收集驗(yàn)證的基礎(chǔ)上。用有限元法得到的結(jié)果和用提出的公式得到的結(jié)果分別與現(xiàn)場(chǎng)收集的數(shù)據(jù)進(jìn)行

61、了比較。理論公式和現(xiàn)場(chǎng)數(shù)據(jù)相一致，發(fā)現(xiàn)通過(guò)有限元方法得到的結(jié)果更接近真實(shí)的數(shù)據(jù)。</p><p>　　【關(guān)鍵詞】塔機(jī)；靜剛度；控制值；靜位移</p><p><b>　　1.引言</b></p><p>　　Sagirli，Bococlu和Omurlu（2003年）通過(guò)真實(shí)的試驗(yàn)系統(tǒng)實(shí)現(xiàn)了對(duì)旋轉(zhuǎn)伸縮式起重機(jī)的幾何和動(dòng)力學(xué)參數(shù)的模擬[1]。目的是

62、通過(guò)將規(guī)定了相應(yīng)的不同的負(fù)載和操作條件的各種情況，與真實(shí)的系統(tǒng)和模型比較，核實(shí)是否有足夠的模擬精度。在規(guī)定的情況下，脈沖響應(yīng)，響應(yīng)時(shí)間和靜態(tài)響應(yīng)在實(shí)驗(yàn)中被用來(lái)收集系統(tǒng)參數(shù)和變量，如阻尼系數(shù)，汽缸排量和伸縮臂的剛度等。以下是兩種不同的模擬情況下靜態(tài)響應(yīng)和脈沖響應(yīng)的結(jié)果。Barrett和Hrudey（1996年）針對(duì)橋式起重機(jī)的進(jìn)行了一系列試驗(yàn)，來(lái)研究起重機(jī)的結(jié)構(gòu)剛度，起重機(jī)的結(jié)構(gòu)慣性，鋼索吊鉤系統(tǒng)的剛度，有效負(fù)載和吊裝作業(yè)時(shí)的初始條件，在

63、提升重物時(shí)是如何影響動(dòng)態(tài)響應(yīng)峰值的[2]。這些因素隨時(shí)間的變化，在測(cè)試項(xiàng)目中獲得的位移，加速度，纜索拉力，橋梁彎矩和端車(chē)反作用力值各不相同。動(dòng)態(tài)增益比的值被定義為：位移，橋梁彎矩和端車(chē)反作用力的動(dòng)態(tài)峰值超過(guò)相應(yīng)的靜態(tài)值。提出兩自由度的分析模型和用一個(gè)具有三個(gè)無(wú)因次參數(shù)的函數(shù)計(jì)算動(dòng)態(tài)增益比的理論值，來(lái)描敘起重機(jī)和有效載荷系統(tǒng)。Grierson（1991年）審議了靜載荷作用下的設(shè)計(jì)，即組成的各成員會(huì)自動(dòng)使用完全符合設(shè)計(jì)標(biāo)準(zhǔn)</p>

64、;<p>　　GB 3811—1983《起重機(jī)設(shè)計(jì)規(guī)范》和GB/T 13752—1992《塔式起重機(jī)設(shè)計(jì)規(guī)范》對(duì)塔式起重機(jī)靜態(tài)剛性的要求為：“塔式起重機(jī)在額定起升載荷作用下，塔身在臂架連接處(或在臂架轉(zhuǎn)柱連接處)的水平靜位移位△x應(yīng)不大于H/100。其中H，對(duì)自行式塔式起重機(jī)為塔身在臂架連接處至軌面的垂直距離，對(duì)附著式塔式起重機(jī)為塔身在臂架連接處至最高一個(gè)附著點(diǎn)的垂直距離?！?lt;/p><p>　　針

65、對(duì)塔機(jī)靜態(tài)剛性在上述規(guī)范中控制過(guò)嚴(yán)的問(wèn)題(△x≤H/100)，對(duì)塔機(jī)靜剛度進(jìn)行了專項(xiàng)研究，以配合修訂GB/T 3811—1983《起重機(jī)設(shè)計(jì)規(guī)范》。</p><p>　　本文其余內(nèi)容安排如下。第2節(jié)，對(duì)塔機(jī)靜剛度控制值的修訂意見(jiàn)。第3節(jié)，塔機(jī)靜剛度控制值合理性驗(yàn)證。第4節(jié)，與靜剛度控制值對(duì)應(yīng)的塔身靜位移理論計(jì)算方法。第5節(jié)，塔身靜位移各種計(jì)算方法與實(shí)測(cè)值的比較。第6節(jié)，對(duì)本文做一個(gè)簡(jiǎn)單的總結(jié)。</p>

66、<p>　　2．對(duì)塔機(jī)靜剛度控制值的修訂意見(jiàn)</p><p>　　由于高強(qiáng)度鋼的普遍使用，結(jié)構(gòu)的強(qiáng)度及穩(wěn)定性已不難滿足，結(jié)構(gòu)的剛度要求正成為制約塔機(jī)向輕量化發(fā)展的重要指標(biāo)。修訂后的塔機(jī)靜剛度控制值不僅要滿足當(dāng)前產(chǎn)品開(kāi)發(fā)的需要，還應(yīng)適應(yīng)今后的發(fā)展。針對(duì)我國(guó)實(shí)際情況，要保證塔機(jī)產(chǎn)品的質(zhì)量，使塔機(jī)的設(shè)計(jì)和檢測(cè)有據(jù)可依，適當(dāng)放寬塔機(jī)靜剛度控制值是必然趨勢(shì)。</p><p>　　圖1

67、塔機(jī)靜位移示意圖</p><p>　　在對(duì)塔機(jī)生產(chǎn)廠家和用戶進(jìn)行大量調(diào)研走訪的基礎(chǔ)上，于，王，鄭和王提出了擬推薦的塔機(jī)靜剛度控制值及對(duì)應(yīng)的檢測(cè)方法，即以空載狀態(tài)下臂根鉸點(diǎn)的位置(此時(shí)相對(duì)于未變形時(shí)塔身理論中心線有一后傾位移，如圖1)為基準(zhǔn)，吊載后臂根鉸點(diǎn)的絕對(duì)位移△x作為靜位移測(cè)量值，用該值來(lái)衡量塔機(jī)的靜剛度[12]。這種測(cè)量靜位移的方法也是目前塔機(jī)檢測(cè)驗(yàn)收時(shí)使用的方法，該值較易測(cè)得，且所測(cè)值中基本消除了塔身垂直

68、度偏差。于，王，鄭和王建議與此測(cè)量方法對(duì)應(yīng)的靜位移控制值為△x≤1.33H/100，即靜剛度控制值比上述“規(guī)范”中的控制值增大1/3。 </p><p>　　根據(jù)“《起重機(jī)設(shè)計(jì)規(guī)范》修訂專題研究項(xiàng)目鑒定評(píng)審會(huì)“專家的意見(jiàn)，認(rèn)為于，王，鄭和王推薦的塔機(jī)靜剛度控制值是一個(gè)合適的限度值，順應(yīng)了塔機(jī)行業(yè)放寬△x限值的修改呼聲，且該方法檢測(cè)方

69、便，但為了與國(guó)際標(biāo)準(zhǔn)的系數(shù)取值系列一致，建議塔機(jī)靜剛度控制值取為△x≤(1.34/100)H。</p><p>　　放大塔機(jī)靜剛度控制值(1.34H/100)，可以降低塔機(jī)成本，使塔機(jī)向輕量重載化發(fā)展，利于行業(yè)的技術(shù)進(jìn)步。</p><p>　　3, 塔機(jī)靜剛度控制值合理性驗(yàn)證</p><p>　　為使修訂后的塔機(jī)靜剛度控制值能真實(shí)地反映當(dāng)前塔機(jī)靜剛度的實(shí)際情況，專題

70、研究組對(duì)正在使用壽命期限內(nèi)并具有代表性的20種型號(hào)塔機(jī)的靜剛度進(jìn)行了實(shí)測(cè)(見(jiàn)表1)。結(jié)果表明，按現(xiàn)行測(cè)量方法，并滿足現(xiàn)行“規(guī)范”中靜剛度控制值H/100的塔機(jī)，只有一種型號(hào)(序號(hào)5)，占5%；而靜剛度測(cè)量值不大于1.34H/100的有15個(gè)，占75%。由此可見(jiàn)，適當(dāng)放大塔機(jī)靜剛度控制值，能使大多數(shù)滿足使用要求的塔機(jī)通過(guò)檢測(cè)部門(mén)的驗(yàn)收。</p><p>　　表1 20種不同型號(hào)的塔機(jī)塔身靜剛度實(shí)測(cè)值及原控制值&l

71、t;/p><p>　　需要說(shuō)明的是，這20種型號(hào)的塔機(jī)到目前為止，均能正常使用，且性能優(yōu)良。</p><p>　　4. 與靜剛度控制值對(duì)應(yīng)的塔身靜位移理論計(jì)算方法</p><p>　　靜位移計(jì)算方法可采用傳統(tǒng)力學(xué)方法或有限元法，傳統(tǒng)力學(xué)方法的計(jì)算模型有實(shí)體壓彎桿件力學(xué)模型和格構(gòu)式桁架力學(xué)模型，前者簡(jiǎn)單實(shí)用，后者精度略高但計(jì)算繁瑣。</p><p>

72、;　　4.1實(shí)體壓彎桿件理論力學(xué)模型</p><p>　　根據(jù)塔機(jī)的靜位移力學(xué)模型圖2所示，實(shí)體壓彎桿件力學(xué)模型可得到與本文所述靜位移測(cè)量值相對(duì)應(yīng)的理論計(jì)算值，因按本文所述測(cè)量方法，塔機(jī)自重載荷引起的彎矩在空載及吊載兩種狀態(tài)下理論上可完全相抵，又因測(cè)量靜位移時(shí)不考慮風(fēng)載及其它水平載荷，故圖2的計(jì)算模型中只有垂直載荷N及吊重引起的彎矩M，其撓曲桿的微分方程為:</p><p><b&g

73、t;　　(1)</b></p><p>　　求解上式可得到塔身項(xiàng)部靜位移的精確計(jì)算式：</p><p><b>　　(2)</b></p><p><b>　　式中</b></p><p><b>　　(3)</b></p><p>　　N—

74、—在額定起升載荷作用下，塔身與臂架連接處以上所有垂直力(包括塔身自重在此處的折算力，折算方法見(jiàn)GB/T 13752-1992附錄G)；</p><p>　　M——吊重引起的彎矩，M =OR，Q為額定起升載荷，R為與Q對(duì)應(yīng)的工作幅度。 </p><p>　　圖2 塔機(jī)的靜位移力學(xué)模型</p><p>　　也可將

75、上式變換如下。由壓桿的歐拉臨界載荷,</p><p><b>　　(4)</b></p><p>　　對(duì)懸臂壓桿：=2，故有： （5）</p><p>　　將三角函數(shù)secu展開(kāi)為冪級(jí)數(shù)</p><p><b>　　(6)</b></p><p><b>　　則式(

76、2)可簡(jiǎn)化成</b></p><p>　　將f近似值定義為 ，則有</p><p><b>　　(8)</b></p><p>　　式中 △M——額定起升載荷對(duì)塔身中心線的彎矩M引起的塔身與起重臂連接處的水平位移， (9)</p><

77、p>　　——考慮軸向力影響的撓度放大系數(shù)。</p><p><b>　　4.2 有限元模型</b></p><p>　　這是有限元法可能的塔式起重機(jī)的模型。有限元模型是基于簡(jiǎn)化的塔式起重機(jī)結(jié)構(gòu)幾何模型。作為一種數(shù)值計(jì)算法，由有限元得到的法結(jié)果也是近似的。該塔式起重機(jī)模型被分成許多元素（如圖3所示）。在這種塔式起重機(jī)的模型中有3種類(lèi)型的元素：橫梁，橫桿和翼梁元素。

78、彎的支撐用橫梁元素作模型。腹部支撐和可伸長(zhǎng)的支撐使用橫桿元素作模型。鋼絲繩用鏈接元素作模型。平衡重物用塊元素作模型。商業(yè)有限元程序ANSYS軟件（ANSYS軟件公司，美國(guó)）是用來(lái)建立和解決這個(gè)問(wèn)題，并分析結(jié)果。 </p><p>　　該材料性能和負(fù)載情況與上述部分相同。塔式起重機(jī)尺寸也與上面闡述的相同。</p><p>　　圖3 塔機(jī)有限元模型</p>

79、<p>　　5. 塔身靜位移各種計(jì)算方法與實(shí)測(cè)值的比較</p><p>　　為了了解不同的計(jì)算方法和精確的測(cè)量之間的錯(cuò)誤值，用解析表達(dá)式（2）和（8）的結(jié)果與數(shù)值結(jié)果相比較，并利用有限元分析程序ANSYS對(duì)其進(jìn)行分析。同時(shí)，比較性實(shí)驗(yàn)數(shù)據(jù)是前面五種類(lèi)型的塔式起重機(jī)的靜態(tài)位移。</p><p>　　3種計(jì)算方法所得靜位移的數(shù)值 (有限元計(jì)算值)與實(shí)測(cè)值的比較見(jiàn)表2。</p

80、><p>　　由表2可知，按式(2)或(3)實(shí)體壓彎桿件力學(xué)模型所得靜位移計(jì)算值的誤差小于12%，而有限元計(jì)算值的誤差均小于10%。因?qū)嶓w壓彎桿件力學(xué)模型主要考慮弦桿的剛度，未考慮腹桿及其布置形式，而腹桿的剛度及布置形式對(duì)塔身的剛度有較大影響。塔身最大靜位移的近似計(jì)算值與相同力學(xué)模型下的精確計(jì)算值相差無(wú)幾，誤差不超過(guò)1%，故按該力學(xué)模型計(jì)算塔身最大靜位移時(shí),可選用式(2)或(8)。</p><p&

81、gt;　　表2 塔身最大靜位移及與實(shí)測(cè)值的比較</p><p>　　塔機(jī)的塔身在實(shí)際工作中相對(duì)理論中心線的最大水平位移值的計(jì)算方法見(jiàn)文獻(xiàn)[12]，計(jì)算載荷除垂直載荷外，還應(yīng)考慮自重及吊重引起的彎矩，沿塔身分布的風(fēng)載荷，因風(fēng)力、變幅、回轉(zhuǎn)起制動(dòng)、回轉(zhuǎn)離心力等引起的塔身端部的集中水平力。</p><p><b>　　6,總結(jié)</b></p><p&g

82、t;　　在分析了收集的許多保持良好的工作狀態(tài)的塔式起重機(jī)靜剛度數(shù)據(jù)的基礎(chǔ)上，如果靜剛度控制值指定為H/100 （根據(jù)GB 3811—1983《起重機(jī)設(shè)計(jì)規(guī)范》和GB/T 13752—1992《塔式起重機(jī)設(shè)計(jì)規(guī)范》的要求 ）調(diào)查中只有5%的塔式起重機(jī)滿足這一要求。如果安本文中提出的使用控制價(jià)值為1.34H/100，則中75%的塔式起重機(jī)可滿足這一要求。</p><p>　　本文中提出的簡(jiǎn)化公式和有限元法被用來(lái)計(jì)算許