机械类外文翻译【FY157】液压支架的最优化设计【中英文WORD】【中文3200字】
收藏
资源目录
压缩包内文档预览：
编号：446472
类型：共享资源
大小：438.16KB
格式：ZIP
上传时间：2015-07-03
上传人：棒***
认证信息
个人认证
康**（实名认证）
湖北
IP属地：湖北
12
积分
- 关 键 词：
-
机械类
外文
翻译
fy157
液压
支架
优化
设计
中英文
word
中文
- 资源描述：
-
机械类外文翻译【FY157】液压支架的最优化设计【中英文WORD】【中文3200字】,机械类,外文,翻译,fy157,液压,支架,优化,设计,中英文,word,中文
- 内容简介：
-
南昌航空大学科技学院学士学位论文 1 Optimal design of hydraulic support m. oblak. Harl and b. butinar Abstract :This paper describes a procedure for optimal determination of two groups of parameters of a hydraulic support employed in the mining industry. The procedure is based on mathematical programming methods . In the first step, the optimal values of some parameters of the leading four-bar mechanism are found in order to ensure the desired motion of the support with minimal transversal displacements. In the second step, maximal tolerances of the optimal values of the response of hydraulic support wil be satisfying. Keywords: four-bar mechanism, optimal design, mathematical programming , approximation method, tolerance 1 Introduction The designer aims to find the best design for the mechanical system considered. Part of thie effort is the optimal choice of some selected parameters of a system. Methods of mathematical programming can be used, Of course, it depends on the type of the systemWith this foemulation, good computer support is assured to look for optimal parameters of the system. The hydraulic support (Fig.1) described by Harl (1998) is a part of the mining industry equipmenr port in the mine Velenje-Slovenia, used for protection of working environment in the gallery. It consists of four-bar mechanisms FEDG and AEDB as shown in Fig.2. The mechanism AEDB defines the path of coupler point C and the mechanism FEDG is used to drive the support by a hydraulic actuator。 nts南昌航空大学科技学院学士学位论文 2 Fig. 1 Hydraulic support It is required that the motion of the support,more precisely, the motion of the point C in Fig.2, is vertical with minimal transversal displacements. If this is not the case, the hydraulic support will not work properly because it is stranded on removal of the earth machine. A prototype of the hydraulic support was tested in a laboratory (Grm 1992). The support exhibited large transversal displacements, which reduce its employability. Thetefore, a redesign was necessary. The project should be improved with minimal cost if possible. It was decided to find the best values for the most problematic nts南昌航空大学科技学院学士学位论文 3 Fig.2 Two four-bar mechanisms Parameters 421 , aaa of the leading four-bar me AEDB with methods of mathematical programming. Otherwise it chanisms would be necessary to change the project, at least mechanism AEDB. The solution of above problem will give us the response of hydranlic support for the ideal system. Real response will be different because of tolerances of various parmeters of the system, which is why the maximal allowed tolerances of paramentsa1,a2,a3,a4 will be calculated support. ,with help of mathematical programming. 2 The deterministic model of the hydraulic support At fist it is necessary to develop an appropriate metical model of the hydraulic support.It could be based on the following assumptions: - the links are rigid bodies, - the motion of individual is relatively slow. The hydraulic support is a mechanism with one degree of freedom. Its kinematics can be model consists of four-bar mechanisms FEDG and AEDB (Oblak et al. 1998).The leading four-bar mechanisms AEDB with methods of mathematical programming. Otherwise it would be nts南昌航空大学科技学院学士学位论文 4 necessary to change the project, at least mechanism AEDB. It is required that the motion of the support,more precisely, the motion of the poit C. Therefore, the path of coupler point C is as near as possible to the desired trajectory k. The synthesis of the four-bar mechanism 1 has been performed with help of motion given by Rao Dukkipati(1989). The general situation is depicted in Fig,3. Fig.3 Trajectory L of the point C Equations of trajectory L of the point C will be written in the coordinate frame considered. Coordinates x and y of the point C will be written with the typical parameters of a four-bar mechanism a1,a2, .a6.The coordinates of points B and D are xB5acos (1) yB=5asin (2) xD=6acos( ) (3) yD=6asin( ) (4) The parameters , 21 aa 6aare related to each other by xB2+ 22a (5) 1)2+ yD2= 24a (6) By substituting (1) (4) into （ 5）（ 6） the response equations of the support are obtained as (x5acos )2+ (y-5a sin )2- 22a =0 (7) x- 6acos( )- 1a 2+ y- 6asin( )2- 24a =0 (8) This equation represents the mathematical model for calculating the optimal values of paramerters a1,a2,a4. 2.1 Mathematical model nts南昌航空大学科技学院学士学位论文 5 The mathemtial model of the system will be formulated in the from proposed by Haug and Arora (1979): gi(u,v) 0, i=1,2, ,l, (10) and response equations hi(u,v)=0, j=1,2, ,m. (11) The vector u=u1,u2, ,unT is called the vector of design variables, v=v1,v2, ,vmTis the vector of response variables and f in(9)is the objective function. Tobperform the optimal design of the leading four-bar mechanism AEDB,the vector of design variables is defined as u= 1a 2a 4a T, (12) and the vector of response variables as v=xyT. (13) The dimensions 3， 5， 6 of the corresponding links are kept fixed. The f(u,v) =maxg0(y)-f0(y)2, (14) where x= g0(y) is the equation of the curve K and x= f0(y) is the equation of the curve L. Suitable limitations for our system will be chosen.The system must satisfy the well-known Grasshoff conditions 02143 aaaa (15) 04132 aaaa (16) Inequalities (15) and (16) express the property of a four-bar mechanism, where the links 42,aa may only oscillate. The condition： uuu (17) Prescribes the lower upper bounds of the design variables. The problem (9)(11)is not dirrctly solvable with the usual gradient-based optimization methods. This could be cirumvented by int express the property of the objective function be written with the typical parameters be written as minun+1 (18) sobject to gi(u,v) 0, i=1,2, ,l, (19) nts南昌航空大学科技学院学士学位论文 6 f(u,v)- un+1 0, (20) and response equations hj(u,v)=0, j=1,2, ,m, (21) where： u=u1 un un+1T v=v1 vn vn+1T A nonlinear programming problem of the leading four-bar mechanism AEDB can therefore be difined as mina7, (22) sobject to constraints 02143 aaaa (23) 04132 aaaa(24) 111 aaa , 222 aaa 444 aaa (25) ),(,0)()( 7200 yyayfyg (26) And respose equationt 0)s in()c o s( 222525 aayax (27) 0)s i n ()c o s ( 2426216 aayaax (28) 3.The stochastic model of the hydraulic support The mathematical model can be used to calculate the parameters of L and K to ensure that the track such as to maintain the distance between the minimum. However the endpoint C calculation L may deviate from the track, because of the movements in the presence of some interference factor. Look at these deviations from what should or not lies in the deviation is in the parametric tolerance tolerance range.Response function (27) - (28) allows us to consider the response variable V vector, the vector of dependent variable V vector design. This means that v = H ( V, H ) function is a mathematical model (22) - (28) foundation, because it describes a response variable V vector and V vector as well as design variables and the mathematical model of the relationship between v. Similarly, the function H used to consider the parameter errors in the value of the maximum permissible value.In the stochastic model, design variable vector u=u1, . , unT can be viewed in U=U1, . , UnT random vector, which means the response nts南昌航空大学科技学院学士学位论文 7 variable vector v=v1, . , vnT is a random vector V=V1, V2, . , VnTV=h ( U ) (29)Suppose design variable U1, . , Un from probability theory and the classification of normal function of Uk ( k=1,2, . , n ) of independence. The main parameters and ( k=1,2, . , n ) can be associated with such as the measurement of this kind of scientific concepts and tolerance to link, such as a =,. So as long as the choice of suitable existence probability, k=1,2, . , n (30)Type (30) is calculated the results of.Random vector V probability distribution function is search for dependent random vector U probability distribution function and its actual computability. Therefore, random vector V is described by mathematical properties, and the properties were identified using Taylor on u=u1, . , unT h approximation function description, or with the aid of Oblak and Harl in the Monte Carlo method. 3.1 The mathematical model Used to calculate the allowable error of hydraulic support optimization mathematical model will be nonlinear problem of independent variable w= 1a 2a 4a T (31) and objective function 421111)( aaawf (32) With conditions 0 EY (33) 111 aaa , 222 aaa 444 aaa (34) In（ 33）， E is the maximal allowed standard deviation of coordinate x of the point C and jAj jiY aag 2421 ),(61 A=1,2,4 (35) The nonlinear programming problem for calculating the optmal tolerances could be therefore defined as ： )111m in (421 aaa (36) Subject to constraints 0 EY (37) 111 aaa , 222 aaa 444 aaa (38) nts南昌航空大学科技学院学士学位论文 8 4.Numerical examply The carrying of the hydraulic support is 1600kN. Both four-bar AEDB andFEDG must fulfill the following demand： they must allow minimal transversal displacements of the point C, and， they must provide sufficient side stability. The parameters of the hydraulic support (Fig.2) are given in Table 1. The drive mechanism FEDG is specified by the vector TT dbbbb 1 3 1 0,1 2 5 1),1 3 2 5(,4 0 0, 4321 (mm) (39) And the mechanism AEDB by TTaaaa 1 3 1 0,382,1 3 6 0,674,4321 (mm) In(39),the parameter d is a walk of the support with maximal value of 925 mm. Parameters for the shaft of the mechanism AEDB are given in Table 2. 4.1Four connecting rod AEDA optimization Four link model AEDA related data in equation (22) - (28) are expressed. ( Fig 3). C lemniscate of maximum horizontal offset for65mm. That is why type (26) for the 0)65( 7 ax (41) Rod and bar between AE AA angle in the range of 76.8o and 94.8o, will be a number , 21 xx 19xsuccessively introduced formula (41) obtained results are listed in table 3. These points corresponding to the angle of ,21 22 192in the range of 76.8o,94.8o and they each angle difference of1 nts南昌航空大学科技学院学士学位论文 9 The design variables of the minimum and maximum range is Tu 0,1280,1330,640 (mm) (42) Tu 30,1 3 4 0,1 3 9 0,7 0 0 (mm) (43) Nonlinear design problems in equation (22) and (28) in the form of. This problem by Kegl et al (1991) based on the approximation of the optimal approximation solution. By using the direct method of distinguishing to calculate design derived data. Design variables for the initial value TTaaaa 30,1 3 1 0,1 3 6 0,674, 70402010 (mm) (44) Optimization of design parameters through calculation is repeated 25 times Table3 node C corresponding to the X and Y values 角度)(2 o x初值 (mm) y初值 (mm) x终值 (mm) y终值 (mm) 76.8 66.78 1784.87 69.47 1787.50 77.8 65.91 1817.67 68.74 1820.40 78.8 64.95 1850.09 67.93 1852.92 79.8 63.92 1882.15 67.04 1885.07 80.8 62.84 1913.85 66.12 1916.87 81.8 61.75 1945.20 65.20 1948.32 82.8 60.67 1976.22 64.29 1979.44 83.8 59.65 2006.91 63.46 2010.43 84.8 58.72 2037.28 62.72 2040.70 85.8 57.92 2067.35 62.13 2070.87 86.8 57.30 2097.11 61.73 2100.74 87.8 56.91 2126.59 61.57 2130.32 88.8 56.81 2155.80 61.72 2159.63 89.8 57.06 2184.74 62.24 2188.67 90.8 57.73 2213.42 63.21 2217.46 91.8 58.91 2241.87 64.71 2246.01 nts南昌航空大学科技学院学士学位论文 10 92.8 60.71 2270.08 66.85 2274.33 93.8 63.21 2298.09 69.73 2302.44 94.8 66.56 2325.89 70.50 2330.36 Tu 65.3,88.1 3 0 9,74.1 3 6 0,42.6 7 6* (mm) In Table 3 of C x values and Y values respectively corresponding to the design variables and the variables of optimization design line )。 Fig 4diagram represents the endpoint C started the lemniscate locus L ( dotted line) and perpendicular to the ideal trajectory K ( solid line). Lateral displacement and the trajectory of Figure 4graph represents the endpoint C started the lemniscate locus L ( dotted line) and perpendicular to the ideal trajectory K ( solid line). Fig.4 Trajectories of the point C 4.2 Four connecting rod mechanism AEDA optimal error In the nonlinear problem (36) - (38), selection of independent variables of the minimum and maximum value Tw 0 0 1.0,0 0 1.0,0 0 1.0 (mm) (46) Tw 0.3,0.3,0.3 (mm) (47) Independent variable initial value nts南昌航空大学科技学院学士学位论文 11 Tw 1.0,1.0,1.00 (mm) (48) Trajectory deviation to chose t
- 温馨提示:
1: 本站所有资源如无特殊说明，都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等，如果需要附件，请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸，网页内容里面会有图纸预览，若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对用户上传分享的文档内容本身不做任何修改或编辑，并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容，请与我们联系，我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
人人文库网所有资源均是用户自行上传分享，仅供网友学习交流，未经上传用户书面授权，请勿作他用。
川公网安备: 51019002004831号