外文原文Computer-aided design of floating head heat exchanger based on UG software1 introductionThe EDS of Unigraphics (UG) software is currently the worlds most advanced integrated CAD/CAM/CAE of high-end software, widely used in aerospace, automobile, shipbuilding, general machinery and consumer electronics and other industrial fields.UG software is nowadays many of the worlds leading industrial product designer and manufacturer for concept design, industrial design, mechanical structure design and engineering simulation, digital manufacture technology .In China, the UG software has with Pro/E software to become the most popular with the users and the general acceptance of the three-dimensional parametric design software, for the popularization and improvement of Chinas manufacturing CAD technology has played a positive and significant effect .But in the current domestic users, most designers only use CAD and CAM module of UG software, the CAE module is rusty, and domestic information about UG and books to introduce CAE are few.In the developing of computer and CAD technology in modern times, the finite element analysis method will get more and more widely in engineering design and analysis, finite element analysis software and the integrated application of CAD system is to make the design level happen a qualitative leap, it can increase the reliability of the products and engineering, many conventional calculation doesnt give a analysis of the data, before the product manufacturing or engineering construction found potential problems in advance.2main components of floating head heat exchanger CAD2.1 parts modelingUG solid Modeling module (Modeling) USES the compound Modeling technology, the parameter design and characteristics of geometric design method combining Modeling.Mainly has the entity modeling, wire frame modeling, free-form surface modeling, etc. Three 4.Specific use what kind of modeling method, according to the characteristics of the object, we usually use mainly entity modeling.In entity parts model, can use basic voxel to establish a simple entity, can also be based on the curve to establish various scanning, sketches the stretching, rotating entity, can also use the system to provide features to create a variety of body.For a component model, although there is no a fixed sequence modeling and modeling methods, but still have certain rules to follow.Generally should be according to the structure characteristics of the components, to set up a basic voxel or scanning features, and then gradually create parts of holes, slotting, cavity, convex sets, convex pad and user defined features, finally to create roundingoff, chamfering, thread, pruning and arrays.According to the basic principle of floating head of floating-head type heat exchanger tube plate, saddle, tube box, shell and tube bundle main components such as 3 d modelling, model is intuitive, as shown in figure 1-5.2.2 parts and componentsUG assembly module (Assemblies) using a pointer assembly parts rather than copy parts to realize virtual assembly 5, can reduce the memory requirements of assembly, check the assembly model in time if there is a design size of interference, the smooth progress of the actual assembly model for the future provide a reliable guarantee.Assembly information can be easily caused by the draw assembly drawings, and can quickly generate assembly diagram, save map assembly drawing and parts of time and cost.When change of assembly of parts, assembly will be automatically updated.Figure 6 to use the corresponding matching relationship of floating head heat exchanger assembly drawing, and transparent way outside shell shows the internal form of floating head heat exchanger assembly relation, the whole body of the heat exchanger is more intuitive.2.3 to generate two-dimensional engineering graphicsUG engineering drawing module (Drafting) can be easily with the entity model coordinated two-dimensional engineering graphics.When the entity model changes, the size of the engineering drawing sync automatically updates, reduce model change time needed for two-dimensional chart updates, fundamentally put an end to the traditional size contradictions in the design of two-dimensional engineering graphics, throw line, such as common errors, so as to ensure the correct of two-dimensional engineering graphics.Based on the floating head heat exchanger tube plate, for example by adding a master model view, projection views and local amplification figure views such as establishing two-dimensional engineering graphics, figure 7 is according to our country perfect tube plate drawing standards to modify the default drawing parameters of two-dimensional engineering graphics. 3 CAE implementation of floating head heat exchangerCAE analysis module of UG (Scenario) using the worlds most advanced calculator, such as the MSC/NASTRAN, MSC/PATRAN and MDI/were ADAMS, MOLDFLOW, etc.UG to the first-class software are not simply integration, but "implant" to it, do the consistency of the user interface, and according to the need to expand the corresponding function.3.1 the installation process of floating head heat exchanger and the medium flow simulationMotion simulation is the main part of UG/CAE to, it can be on any 2 d or 3 d institutions complex kinematics simulation analysis, dynamic analysis and design.Through the above of floating head heat exchanger of the three-dimensional entity model is set up, using UG Scenario For the function of the Motion to the three-dimensional solid model of floating head heat exchanger need movement components are given in the kinematics characteristic of a certain to set up certain connections between the parts, thus the Motion of floating head heat exchanger is established the simulation model, and output the corresponding animation.The entire model are verified by simulation movement assembly and the rationality of the design of motion mechanism.The floating head heat exchanger structure and installation process more intuitive, more image, vivid internal medium flow.3.2 the finite element analysis of the saddleThe Scenario of UG for Structures is an integrated CAE tools.When concrete analysis part structure, the module will automatically with the parts of the structure of the network partitioning, boundary constraint and load condition changes correspondingly change, which the new results are obtained.So repeatedly, can be more easily scheme analysis, choose the optimal solution.Upon confirmation of scheme, digital model of CAD module will automatically change to get the best design model.In the floating head heat exchanger, saddle is used to support the horizontal heat exchanger 6, the design requirements and the saddle should have sufficient strength and resistance to deformation ability.This paper simulated the saddle by heat exchanger of the effect of gravity stress, the stress is displayed through the clouds, the size of the force function and is accompanied by the saddle and the deformation.3.2.1 import master model and set the parametersImport figure 2 saddle as the main model, into the structure analysis module.Saddle material is Q235A, elastic modulus E = 220 x 109 pa, poissons ratio u = 0.3, density of rho = 7.85 x 10-6 kg/mm3.Material properties as shown in the table 1.3.2.2 applied load and constraintsPressure on the saddle here only consider heat exchanger, the heat exchanger and the total weight of the fluid W / 2 = 50000 n, with the circular arc of the bearing load ACTS on the saddle surface, as shown in figure 8, since the role of the saddle by anchor bolt, with anchor bolt is fixed on the ground.Symmetry constraint in the bolt hole, at the hem of vertical displacement constraints.As shown in figure 9.3.2.3The finite element grid was divided Meshing was done for the whole model, the use of smart grid, such a finer division of grid, the results of the analysis more accurate, this paper choose the UG software bring UGVM network generator four nodes tetrahedron three-dimensional grid, mesh of finite element model is shown in figure 10. 3.2.4 solving and result outputPrior to calculation, the finite element model for a check to see whether setting error, the system will provide a inspection report, can be set according to the report of some unreasonable, modified the calculation is reasonable, no error message.Output saddle seat move diagram (see figure 11) and stress diagram (see figure 12), figure 11 shows the saddle on the Z axis direction due to the pressure of the heat exchanger and the displacement in the Z axis.Can consider when processing between two straight floor with two support bar, to strengthen the resistance to deformation ability of the saddle.Figure 12 shows the saddle load cases, the two straight floor produces large stress, and on the floor with spot welding with gasket stress concentration.Other local stress distribution is more homogeneous.Therefore, we in the machining process of the saddle to improve the quality of the weld on select material is available in the separation of high strength material. 4 conclusionCreate of floating head heat exchanger using UG 3 d model of the parts and image, vivid, intuitive reflect the structure of floating head heat exchanger;Using UG to the strength analysis of some parts effectively improves the reliability of these parts;Production of three-dimensional dynamic simulation for engineering and technical personnel to master the structure and working principle of floating head heat exchanger;For producers and installers save analysis time, improve the production efficiency at the same time.Visible, along with the development of the computer aided technology and computer network technology, the heat exchanger will realize from the design, manufacturing to sales and maintenance of computer and information technology.With the aid of the powerful features of the computer aided technology, can realize the optimal design of heat exchanger, greatly improve the reliability of heat exchanger, at the same time with the aid of computer network technology, can realize resource sharing in the whole industry, improve the efficiency of heat exchanger design, manufacture, save a lot of production cost and create greater economic benefits for the enterprise.譯文基于UG軟件的浮頭式換熱器計(jì)算機(jī)輔助設(shè)計(jì)1 前言 美國(guó)EDS公司推出的Unigraphics(簡(jiǎn)稱UG)軟件是當(dāng)前世界上最先進(jìn)的集成CAD/CAM/CAE的高端軟件，廣泛應(yīng)用于航空航天、汽車、造船、通用機(jī)械和消費(fèi)電子產(chǎn)品等工業(yè)領(lǐng)域。UG軟件被當(dāng)今許多世界領(lǐng)先的工業(yè)產(chǎn)品設(shè)計(jì)商與制造商用來(lái)從事概念設(shè)計(jì)、工業(yè)設(shè)計(jì)、機(jī)械結(jié)構(gòu)設(shè)計(jì)以及工程仿真、數(shù)字化制造等各個(gè)技術(shù)領(lǐng)域。在中國(guó)，軟件已經(jīng)和Pro/等軟件一起成為最受用戶歡迎和普遍接受的三維參數(shù)化設(shè)計(jì)軟件，為中國(guó)制造業(yè)CAD技術(shù)的普及和提高起到了積極顯著的作用。但就目前國(guó)內(nèi)用戶而言，大多數(shù)設(shè)計(jì)者只使用UG軟件中的CAD和CAM模塊，對(duì)CAE模塊比較生疏，而國(guó)內(nèi)關(guān)于的資料與書籍對(duì)CAE也很少有介紹。在計(jì)算機(jī)和CAD技術(shù)大力發(fā)展的當(dāng)今時(shí)代，有限元分析方法在工程設(shè)計(jì)和分析中將得到越來(lái)越廣泛的重視，有限元分析軟件與CAD系統(tǒng)的集成應(yīng)用使設(shè)計(jì)水平發(fā)生了質(zhì)的飛躍，它能增加產(chǎn)品和工程的可靠性，得到許多常規(guī)計(jì)算無(wú)法得出的分析數(shù)據(jù)，在產(chǎn)品制造或工程施工前預(yù)先發(fā)現(xiàn)潛在的問(wèn)題。2 浮頭式換熱器的主要零部件CAD實(shí)現(xiàn)2.1 零件建模 UG實(shí)體建模模塊(Modeling)采用復(fù)合建模技術(shù)，將參數(shù)設(shè)計(jì)和特征幾何設(shè)計(jì)等方法結(jié)合起來(lái)建模。主要有實(shí)體建模、線框建模、自由曲面建模等3種4。具體用哪一種建模方法，要依據(jù)對(duì)象的特點(diǎn)而定，我們通常用到的主要是實(shí)體建模。在建立實(shí)體零件模型時(shí)，既可以用基本體素建立簡(jiǎn)單的實(shí)體，也可以通過(guò)對(duì)曲線、草圖的拉伸、旋轉(zhuǎn)建立各種掃描實(shí)體，還可以用系統(tǒng)提供的特征創(chuàng)建各種特征體。對(duì)于一個(gè)零件模型，雖然沒有一種固定的建模順序和建模方法，但是還是有一定規(guī)律可循的。一般應(yīng)根據(jù)零部件的結(jié)構(gòu)特點(diǎn)，先建立一個(gè)基本體素或掃描特征，再逐步創(chuàng)建零件的孔、鍵槽、型腔、凸臺(tái)、凸墊及用戶定義等特征，最后創(chuàng)建倒圓、倒角、螺紋、修剪和陣列等特征。按照上述基本原則對(duì)浮頭式換熱器浮頭管板、鞍座、管箱、筒體及管束等主要零部件進(jìn)行三維造型，模型真實(shí)直觀，如圖1-5所示。2.2零部件裝配 UG裝配模塊(Assemblies)使用指針裝配零件而不是拷貝零件實(shí)現(xiàn)虛擬裝配5，可以使裝配的內(nèi)存需求減少，及時(shí)檢查裝配模型是否存在設(shè)計(jì)尺寸干涉，為將來(lái)實(shí)際裝配模型的順利進(jìn)行提供可靠保證。由此所產(chǎn)生的裝配信息可以方便地繪制裝配圖，并能快速生成裝配分解圖，節(jié)省繪制裝配圖和零件圖的時(shí)間和成本。當(dāng)組成裝配的零件有所改變時(shí)，裝配會(huì)自動(dòng)更新。圖6為運(yùn)用相應(yīng)的配對(duì)關(guān)系建立的浮頭式換熱器裝配圖，并以外殼體透明的方式展示了浮頭式換熱器內(nèi)部組建的裝配關(guān)系，使換熱器的整體機(jī)構(gòu)更加真實(shí)直觀。 2.3二維工程圖生成 UG工程制圖模塊(Drafting)可以方便地得到與實(shí)體模型協(xié)調(diào)一致的二維工程圖。當(dāng)實(shí)體模型改變時(shí)，工程圖尺寸會(huì)同步自動(dòng)更新，減少因模型改變二維圖更新所需時(shí)間，從根本上杜絕傳統(tǒng)的二維工程圖設(shè)計(jì)中尺寸矛盾、丟線等常見錯(cuò)誤，從而保證二維工程圖的正確無(wú)誤。本文以浮頭式換熱器管板為例通過(guò)添加主模型視圖，投影視圖及局域放大圖等視圖建立二維工程圖，圖7為按照我國(guó)制圖標(biāo)準(zhǔn)修改缺省圖紙參數(shù)完善的管板的二維工程圖。3 浮頭式換熱器的CAE實(shí)現(xiàn) UG的CAE分析模塊(Scenario)采用世界上最先進(jìn)的計(jì)算器，如MSC/NASTRAN、MSC/PATRAN、MDI/ADAMS、MOLDFLOW等。UG對(duì)這些一流的軟件并不是簡(jiǎn)單地集成，而是“植入”到其中，做到用戶界面的一致性，并根據(jù)需要擴(kuò)充相應(yīng)的功能。3.1浮頭式換熱器的安裝過(guò)程及介質(zhì)流動(dòng)仿真 運(yùn)動(dòng)仿真是UG/CAE模塊中的主要部分，它能對(duì)任何二維或三維機(jī)構(gòu)進(jìn)行復(fù)雜的運(yùn)動(dòng)學(xué)分析、動(dòng)力分析和設(shè)計(jì)仿真。通過(guò)以上建立的浮頭式換熱器的三維實(shí)體模型，利用UG的Scenario For Motion的功能給浮頭式換熱器的三維實(shí)體模型中的需要運(yùn)動(dòng)的部件賦予一定的運(yùn)動(dòng)學(xué)特性，再在各個(gè)部件之間設(shè)立一定的連接關(guān)系，從而建立浮頭式換熱器的運(yùn)動(dòng)仿真模型，并輸出相應(yīng)的動(dòng)畫。通過(guò)運(yùn)動(dòng)仿真檢驗(yàn)了整個(gè)模型裝配及運(yùn)動(dòng)機(jī)構(gòu)設(shè)計(jì)的合理性。使浮頭式換熱器結(jié)構(gòu)及安裝過(guò)程更直觀、內(nèi)部介質(zhì)流動(dòng)更加形象、逼真。3.2鞍座的有限元分析 UG的Scenario for Structures是一個(gè)集成的CAE工具。在具體分析零件結(jié)構(gòu)時(shí)，該模塊會(huì)自動(dòng)隨零件結(jié)構(gòu)的網(wǎng)絡(luò)劃分、邊界約束、載荷工況發(fā)生的變化作相應(yīng)的變化，從而得出新的結(jié)果。這樣反復(fù)多次，可很方便地進(jìn)行多方案的分析，從中選出最優(yōu)的方案。方案一經(jīng)確認(rèn)，CAD模塊的數(shù)字模型也會(huì)自動(dòng)地改變，從而得到最佳的設(shè)計(jì)模型。在浮頭式換熱器中，鞍座是用來(lái)支撐臥式換熱器的6，設(shè)計(jì)要求鞍座要有足夠的強(qiáng)度和抗變形能力。本文模擬鞍座受換熱器的重力的作用而產(chǎn)生的應(yīng)力，該應(yīng)力的大小是通過(guò)云圖顯示出來(lái)的，并伴隨有鞍座受力作用而產(chǎn)生的變形。3.2.1 導(dǎo)入主模型并設(shè)置參數(shù) 導(dǎo)入圖2鞍座作為主模型，進(jìn)入結(jié)構(gòu)分析模塊。鞍座材料為Q235A，彈性模量E=220109Pa，泊松比=0.3，密度=7.8510-6 kg/mm3。材料特性詳見表1。3.2.2 施加載荷與約束 在這里只考慮換熱器對(duì)鞍座的壓力，即換熱器與流體的總重量W/2=50000N，以軸承載荷作用于鞍座的圓弧面上，如圖8所示，因?yàn)榘白艿啬_螺栓的作用，以地腳螺栓固定在地面上。在螺栓孔處產(chǎn)生對(duì)稱約束，在底邊上產(chǎn)生豎直方向的位移約束。如圖9所示。 3.2.3 劃分有限元網(wǎng)格對(duì)整個(gè)模型進(jìn)行網(wǎng)格劃分，使用智能網(wǎng)格劃分，這樣劃分出來(lái)的網(wǎng)格更細(xì)，分析的結(jié)果更精確，本文選擇UG軟件自帶的UGVM網(wǎng)絡(luò)生成器生成四節(jié)點(diǎn)四面體三維立體網(wǎng)格，劃分網(wǎng)格后的有限元模型如圖10所示。3.2.4 求解及結(jié)果輸出在進(jìn)行計(jì)算之前，對(duì)有限元模型進(jìn)行一次檢查是否設(shè)置錯(cuò)誤，系統(tǒng)會(huì)提供一份檢查報(bào)告，可以根據(jù)報(bào)告對(duì)一些不合理的設(shè)置進(jìn)行修改，本次計(jì)算合理，無(wú)錯(cuò)誤信息。輸出鞍座位移圖（詳見圖11）和應(yīng)力圖（詳見圖12），圖11說(shuō)明鞍座在Z軸方向上因受換熱器的壓力而產(chǎn)生的在Z軸方向上的位移。在加工時(shí)可以考慮在兩直肋板間加上兩根支撐桿，以加強(qiáng)鞍座的抗變形能力。圖12說(shuō)明鞍座負(fù)重情況下，在兩直肋板產(chǎn)生較大應(yīng)力，且在肋板與墊片的焊接處有應(yīng)力集中情況發(fā)生。其它地方應(yīng)力分布較均勻。故此，我們?cè)诎白募庸み^(guò)程中要提高焊縫的質(zhì)量，選材上可在這部分選強(qiáng)度高的材料。4 結(jié)論用UG創(chuàng)建的浮頭式換熱器零部件的三維模型，形象、逼真，非常直觀的反映了浮頭式換熱器構(gòu)造；運(yùn)用UG對(duì)部分零部件進(jìn)行的強(qiáng)度分析有效地的提高了這些零部件可靠性；制作的三維動(dòng)態(tài)模擬能夠方便廣大工程技術(shù)人員掌握浮頭式換熱器的結(jié)構(gòu)與工作原理；為生產(chǎn)者以及安裝者節(jié)省了分析時(shí)間，同時(shí)提高了生產(chǎn)效率?？梢姡S著計(jì)算機(jī)輔助技術(shù)和計(jì)算機(jī)網(wǎng)絡(luò)技術(shù)的發(fā)展，換熱器將實(shí)現(xiàn)從設(shè)計(jì)、制造到銷售、維護(hù)的計(jì)算計(jì)化與信息化。借助計(jì)算機(jī)輔助技術(shù)的強(qiáng)大功能，完全可以實(shí)現(xiàn)換熱器的最優(yōu)化設(shè)計(jì)，大大提高換熱器的可靠性，同時(shí)借助計(jì)算機(jī)網(wǎng)絡(luò)技術(shù)，可以實(shí)現(xiàn)在全行業(yè)內(nèi)的資源共享，提高換熱器設(shè)計(jì)、制造的效率，節(jié)約大量的生產(chǎn)成本，為企業(yè)創(chuàng)造更大的經(jīng)濟(jì)效益。