1附 錄附錄 A 外文文獻(xiàn)原文A1 Establish and research on CA/CAE sysytem of automobile drive axle housing based on virtual prototype technologyVirtual prototype refer to a model which is in the step of product progress, occurring in the computer realm,, aiming at the optimization based on the CAD model used to stimulating analysis product. Virtual prototype in mainly used for test which was failed by physical test. Based on the result which is drawn from the stimulation result, it is easy to modify and guide design, until reach the optimistic design Automobile drive axle housing is a main part of a mobile. disconnect drive axle housing is used for bearing the mobile’s weight ,transferring the load to the wheels Drawing force, braking force lateral force and vertical force are transferred to frame and compartment by drive axle housing. So drive axle housing is either a bearing or a transmission item. If not correctly designed or some problem occurred while manufacturing, drive axle housing may deformed or fracture. As a traditional design method is so costly that is necessary to introduce the virtual prototype technology.A1.1 design scheme Traditional design method for drive axle housing is firstly giving a scheme ,manufacturing , a sample item then a series test (such as stiffness test bending fatigue test and static strenth test )is carried out Apparently this method is very money consuming ,and the final parameter may be not optimal .if adopt the Virtual prototype technology stimulazing kinds of working condition of drive axle housing ,and draw a series of optimal parameters .Based on these parameter the physical machine are carried out to do physical test .this method can save time ,cutting the cost ,thus bring in huge benefit to the enterprise.Modern trial production progress vary largely to the traditional one .As depicted ,in the picture ,A loop is absent in the traditional drive axle housing making virtual prototype can assess the cost quality and manufacturability on the computer. If the assessment is not satisfying, it is necessary to adjust .repeat a loop until reach a ideal parameter.This scheme design a software terrace, providing a interface for Solidworks patron and Nastron ,using superiority of this professional software ,and develop these software ,but a drive axle housing product design terrace.Considering the question of improving the analysis efficiency and simplifying finite element ,this system adopt a method which uses parametric modeling that is totally different from do make up for CAD model .And the CAD model is only used for oversight 2A1.2 Parameterized Modeling by SolidWorksThey are all available for second-time development of SolidWorks for the softwares that support OLE and COM. Because of design requirements, the development software of the system is Delphi and second development software of SolidWorks is OLE. The copyright of SolidWorks is 2006. To use this method, it must be registered for auto-severed including files sldworks.tlb and element files that filenames are SldWorks_TLB.pas severed by SolidWorks under Delphi program environment, and they are available after programs are complied.The topology structure of SolidWorks is typically five layers topology structure. A part is consist of bodies, and bodies include surfaces, and surfaces include edges, and edges include curves and points. It may use record in delphi to define bodies, surfaces and points these data structure and apply respectively to store topology information. The steps of the parameterized modeling of CAD by SolidWorks are as follows: firstly, it must be defined correctly for the relationship between automobile dimension and other dimensions. Secondly, initialize the various record and auto-product the drawing of axle housing using API function. Lastly, it is available for users to check the CAD model and modify various dimensions on the plate. The program can auto-modify the other relative dimensions and redraw the picture in SolidWorks by using the relationships that have been defined previously. A1.3 Patran & Nastran FEA analysisA1.3.1 PCL programMSC/PATRAN provides a fully functions program language for users, as PCL. PCL provide abundant of tables and menus and allow users to read and write all information in Patran database, which structure is similar with C language. The paper develops the analysis module of the automobile drive axle housing, which includes parameterize modeling, ALE, material definition, load cases definition, Nastran analysis submitted and results post-possessing and other functions.There are no special develop environment in PCL, generally the codes are written in test editor and saved as *.pcl format, and then the files are pre-compiled as *.cpp format in DOS, and debug them in Patran at last. The detail operates are as follows:Pre-compile *.pcl file:cpp *.pcl *.cppdebug *.cpp file in patran:!!input *.cppWhen starting, Patran will execute init.pcl file under its root catalogue. The file includes two commands:!!INPUT p3prolog.pcl and !!IPUT p3epilog.pcl. As pre-compile these two files when Patran starts. Users can write commands to initialize Patran starting 3viewport. For example, write commands：!!iput C:\MSC.Software\MSC.Patran\2005_r2\ rearhouse.cpp and rearhouse.init() in p3epilog.pcl, in which, rearhouse.cpp is the second-time development program for automobile drive axle housing. It will influence the starting speed, for this, users can write self-definition functions and compile them into a database, which Patran can call directly. The method is that:Input commands in Patran:!!COMPLIE rearhouse.cpp into rearhouse.plb!!library rearhouse.plb!!llibrar keepopen rearhouse.plbAs this, Patran can load including files when it starts and the speed is rather fast. For initialize the viewport, users need to input that: rearhouse,init().A1.3.2 Program Design FlowcharThe FEA parameterize modeling part is implemented as follows:Input various key parameters into delphi, and they will be compiled and format a file whose suffix is .cpp. The contents of init.pcl can be modified by dephi. As that, users can enter Patran by click “FEA parameterize modeling” in this system, and they will see a new file, whose drawing zone has complete FEA module. The program parts don’t need to communicate with users and just like a back program. In this progress it will need API function of Windows system. Due to they require high communicate for ALE, material definition, load cases definition, Nastran analysis submitted and results post-possessing and other functions, which are not convenient for delphi to control directly, these parts will be written by PCL. Patran may copy the .CPP files to the catalog such as “C:\MSC.Software\MSC.Patra\2005_r2”, and modify the relative contents in init.pcl file. Allowing for the special features of housing modeling and computing speed of computers, the program all use shell elements to simulate housing. Therefore it use sgm_const_surface_extrude() to product shell function when modeling, and use fem_create_mesh_surf_4() to mesh when FEA meshing. A1.4 Software application exampleThis software is established by the delphi computer language. After enter the system, preliminary design of automobile drive axle housing by basis mechanics must be completed to define the key dimension, then CAE/CAD modeling and analyzing of various operating conditions should be starting. The software interface is shown in the Figure A1, Figure A2 shows the solid model of axle housing by SolidWorks parameterized modeling.4Figure A1 The software interfaceFigure A2 The solid model of axle housingTable A1 illustrates material parameters whichComponent Material Modulus of elasticity Poisson ratio DensityDrive axle housing QT400-15 1.962E8 KPa 0.3 7.8E-6 kg/mm^3Half axle casing 45Mn2 2.1E8 KPa 0.28 7.9E-6 kg/mm^3Five operating conditions are analyzed by Patran&Nastran in this system, which are shown in Figure A5, static of 2.5 times full load, driving by the maximum drawing force, brake of full load, turning around of full load, brake of full load in turning around. Longitudinal direction, side direction, vertical direction and revolve of longitudinal direction constraints are laid on at the center of steel plate spring. Load is laid on at the half axle casing, which resulting stress is inconsistent with actual condition, bringing no impact on stress of other parts of axle housing. The result shows that Tresca stress on wheel side is larger in Table A3.Table A2 The stress of axle housing of 5 operating conditions5Static of 2.5 times full loadDriving by the maximum drawing forceBrake of full loadTurning around of full loadBrake of full load in turning aroundStress in critical section 175 87 93.5 158 205The allowable stress of axle housing is 400MPa, the design is very safe, which shown in the Table A2. Figure 8 illustrates the distribution of stress nearby the steel plate spring. Figure A3 The distribution of stress nearby the steel plate springTable A3 illustrates the former 9th order natural frequency of automobile drive axle housing by this system.Table A3 The former 9th order natural frequencyOrder 1 2 3 4 5 6 7 8 9Frequency 181.47 265.91 433.24 614.33 658.76 1119.9 1166 1347.4 1399.6Since the road is not absolutely smooth, automobile natural frequency often occur between 1~20Hz. Resonance of axle housing won’t be caused. This result is reasonable. Figure A4 The 1st order mode of vibration6附錄 B 外文文獻(xiàn)中文翻譯A1 基于虛擬樣機(jī)技術(shù)的汽車驅(qū)動橋橋殼 CAD/CAE 系統(tǒng)的建立于研究虛擬樣機(jī)是指在產(chǎn)品設(shè)計階段，在計算機(jī)世界中，以優(yōu)化設(shè)計思想為指導(dǎo)，以產(chǎn)品 CAD 模型為基礎(chǔ)，利用各種相關(guān) CAE 分析軟件，進(jìn)行產(chǎn)品主要性能仿真分析的數(shù)字模型㈣。虛擬樣機(jī)主要進(jìn)行對物理樣機(jī)而言難以進(jìn)行的試驗，根據(jù)虛擬樣機(jī)反饋的仿真結(jié)果，修正、指導(dǎo)設(shè)計，直至獲得系統(tǒng)級的優(yōu)化設(shè)計方案。 驅(qū)動橋橋殼是汽車上主要零件之一，非斷開式驅(qū)動橋殼起著支承汽車荷重的作用，并將載荷傳給車輪。作用在驅(qū)動車輪上的牽引力、制動力、側(cè)向力和垂向力也經(jīng)過橋殼傳到懸架及車架或車廂上。因此，橋殼既是承載件又是傳力件。如設(shè)計不當(dāng)或制造工藝有問題時，會使橋殼變形或折斷。傳統(tǒng)橋殼設(shè)計方法代價過于昂貴，因此有必要引進(jìn)虛擬樣機(jī)技術(shù)。A1.1 設(shè)計方案以往的橋殼設(shè)計方法都是先提出一種方案，制造出物理樣機(jī)，然后通過剛度試驗、靜強(qiáng)度試驗、彎曲疲勞壽命試驗等多次破壞性的物理試驗來確定其性能參數(shù)、材料特性。顯然這種方法的代價是相當(dāng)昂貴的，而且最后得出的參數(shù)也不一定是最優(yōu)的。如果采用虛擬樣機(jī)技術(shù)先對驅(qū)動橋橋殼工作的各種工況進(jìn)行仿真，在計算機(jī)里面通過參數(shù)優(yōu)化得出一組合理的設(shè)計參數(shù)值，然后再根據(jù)這組合理的參數(shù)值制造出物理樣機(jī)做物理試驗。這種方法節(jié)省時間，降低成本，將為企業(yè)帶來巨大的經(jīng)濟(jì)效益。現(xiàn)代模式的新產(chǎn)品試制過程，和傳統(tǒng)的新產(chǎn)品試制過程有很大不同。A 循環(huán)部分為汽車驅(qū)動橋橋殼新產(chǎn)品試制傳統(tǒng)方法中所無，即虛擬樣機(jī)部分。虛擬樣機(jī)可對設(shè)計質(zhì)量、成本、可制造性（制造工藝性）等指標(biāo)在計算機(jī)上進(jìn)行評價，當(dāng)評價不滿意時，進(jìn)行修改設(shè)計，重復(fù) A 循環(huán)，直到獲得理想的參數(shù)為止。本方案設(shè)計開發(fā)一個軟件平臺，提供 SolidWorks、 Patran&Nastran 的接口，利用兩種專業(yè)應(yīng)用軟件在 CAD 建模和有限元分析方面的優(yōu)勢，分別對二者進(jìn)行二次開發(fā)，建立一個針對汽車驅(qū)動橋橋殼產(chǎn)品的數(shù)字化設(shè)計平臺。考慮到提高有限元軟件的分析效率和有限元模型的簡化問題，本系統(tǒng)采用在Patran 中單獨參數(shù)化建模的方法，而不是直接修改簡化 CAD 模型，而 CAD 模型只用于觀察裝配干涉和生成二維生產(chǎn)圖。A1.2 SolidWorks 參數(shù)化建模凡支持 OLE 和 COM 編程的開發(fā)工具均可用于 SolidWorks 的二次開發(fā)。由于設(shè)計需要本系統(tǒng)采用 Delphi 作為開發(fā)工具，運用 OLE 自動化技術(shù)對 SolidWorks 進(jìn)行二次開發(fā)。SolidWorks 版本為 2006 版。采用這種方法必須在 Delphi 編程環(huán)境中注冊由7SolidWorks 提供的自動化服務(wù)類型庫文件 sldworks.tlb，生成名為 SldWorks_TLB.pas的單元文件，并在編譯程序時引用之方可。SolidWorks 的拓?fù)浣Y(jié)構(gòu)為典型的五層式拓?fù)浣Y(jié)構(gòu)。一個零件對象由體構(gòu)成，體中含面，面中含邊，邊中含曲線和頂點。可用 delphi 中的 record 記錄定義體、面、點數(shù)據(jù)結(jié)構(gòu)，分剔用于存儲各自拓?fù)湫畔?。?SolidWorks 中 CAD 參數(shù)化建模過程如下：首先，定義好驅(qū)動尺寸和其余尺寸間的關(guān)系。其次，初始化各 record，利用 API 函數(shù)自動生成橋殼實體圖形。最后，用戶可以在本軟件平臺上檢查 CAD 模型并修改各尺寸參數(shù)，程序利用預(yù)先定義好的各尺寸間的關(guān)系，自動修改橋殼其余相關(guān)尺寸，在SolidWorks 中重畫橋殼圖形。A1.3 Patran&Nastran 有限元分析。A1.3.1 PCL 編程MSC/PATRAN 為用戶提供了一種全功能的編程語言，即 PCL(PATRAN command language)lsi。 PCL 提供了豐富的表格和萊單庫，使用戶可以方便快捷的編制 Motif 界面，允許用戶讀寫 Patran 數(shù)據(jù)庫中的全部信息，其結(jié)構(gòu)和 C 語言類似。本文利用 PCL 語言開發(fā)包括參數(shù)化建模、自動網(wǎng)格劃分、定義材料、定義工況、提交Nastran 分析和結(jié)果后處理等功能的汽車驅(qū)動橋橋殼分析模塊。PCL 沒有專門的集成開發(fā)環(huán)境，一般都是在文本編輯器中編寫代碼，并將文本保存為*.pcl 格式，然后在 DOS 環(huán)境中將文件預(yù)編譯為 *.cpp 格式，最后在 Patran 中調(diào)試*.cpp 文件。具體操作如下：Patran 每次啟動都會執(zhí)行其根目錄下的 init.pcl 文件，該文件中包含兩個命令：！!INPUT p3prolog.pcl 和！!INPUT p3epilog.pcl。即在 Patran 啟動時預(yù)編譯p3prolog.pcl 和 p3epilog.pcl 文件。用戶可以在此二文件中寫入命令初始化 Patran 啟動界面。如在 p3epilog.pcl 中寫入命令：?。?input C:＼ MSC.Software\MSC.Patran\2005_r2\rearhouse.cpp 和 rearhouse.init0，其中rearhouse.cpp 為汽車驅(qū)動橋橋殼分析二次開發(fā)程序。會影響 Patran 的啟動速度，用戶可以先將自己編寫的函數(shù)編譯到一個數(shù)據(jù)庫中，Patran 可直接調(diào)用。方法如下：在 Patran 命令行中輸入如下命令：！!COMPILE rearhouse.cpp into rearhouse.plb$編譯形成用戶化庫在 init.pcl 文件中輸入如下內(nèi)容：！!library rearhouse.plb! !library keepopen rearhouse.plb如此，Patran 肩動時自動加載庫文件，速度很快，用戶要初始化界面只需在命令8行中輸入：rearhouse.init0。按有限元分析一般流程，本文有限元參數(shù)化建模部分的實現(xiàn)如下：在 delphi 中輸入各關(guān)鍵參數(shù)，經(jīng)過 delphi 編譯后生成一個后綴名為.cpp 的文件，并由 delphi 程序控制修改 init.pcl 文件內(nèi)容，初始化 Patran。即用戶從此軟件系統(tǒng)中點擊“有限元參數(shù)化建模”按鈕就會自動進(jìn)入 patran 中，并看到一個新建的文件，其繪圖區(qū)中已有自動建模完畢的有限元分析模型。在 Patran 看來這部分程序不需要同用戶交互操作，就像一個后臺程序。在此過程中需用到 Windows 系統(tǒng)的 API 函數(shù)。其余網(wǎng)格劃分、定義工況、定義材料、提交 nastran 分析、后處理等工作需要很高昀交互性，不便由 delphi 程序直接控制，因此實現(xiàn)這一部分功能的 PCL 程序單獨編寫。delphi 只將編譯好的實現(xiàn)這部分功能的.cpp 文件拷貝到如“C:＼ MSC.Software\MSC.Patran\2005_r2”這樣的目錄中，并修改 init.pcl 文件相應(yīng)的內(nèi)容，以便初始化 Patran 界面?？紤]到橋殼模型的特殊性以及計算機(jī)計算速度，本程序全部使用殼單元模擬橋殼。因此建模時用到如 sgm_con st_s urface_extrude()‘6】之類的生成殼體的函數(shù)，劃分有限元網(wǎng)格時使用 fem 一一 create_mesh_surf_4()之類的函數(shù)進(jìn)行殼體網(wǎng)格劃分。A1.4 軟件應(yīng)用實例本軟件系統(tǒng)使用 delphi 為開發(fā)語言。進(jìn)入本系統(tǒng)后，必須先根據(jù)基本力學(xué)公式對橋殼進(jìn)行初步設(shè)計，得出橋殼的各關(guān)鍵尺寸，然后方可進(jìn)行 CAD/CAE 參數(shù)化建模和各種工況的分析。圖 A1 為本軟件系統(tǒng)界面，圖 A2 為由 SolidWorks 參數(shù)化建模的橋殼實體圖。圖 A1 汽車驅(qū)動橋橋殼 CAD/CAE 集成系統(tǒng)界面圖9圖 A2 由 solidworks 參數(shù)化建模的某驅(qū)動橋橋殼實體圖系統(tǒng)對該橋殼進(jìn)行有限元分析時所用材料參數(shù)如表 A1 所示。表 Al 汽車驅(qū)動橋橋殼模型材料參數(shù)表零部件 材料 彈性模量 泊松比 密度驅(qū)動橋殼 QT400-15 1.962E8 KPa 0.3 7.8E-6 kg/mm^3半軸套管 45Mn2 2.1E8 KPa 0.28 7.9E-6 kg/mm^3系統(tǒng)調(diào)用 Patran&Nastran 進(jìn)行靜力分析時分別模擬如表 2 所示的 5 種工況，即汽車 2.5 倍滿載靜止時、汽車滿載以最大牽引力行駛時、汽車滿載緊急制動時、汽車滿載轉(zhuǎn)彎時、汽車滿載轉(zhuǎn)彎制動時橋殼所受力的狀況。分析時分別在鋼板彈簧座中心處推力桿支座中心處沿汽車縱向、側(cè)向、垂向以及繞縱向轉(zhuǎn)動施加約束，為消除剛體位移還需要在推力桿支座中心處施加其余約束。載荷加在半軸套管兩軸承中間，這樣使得軸承附近的應(yīng)力和實際不符，但不會影響橋殼其余部分的應(yīng)力分布。分析結(jié)果顯示板簧座和半軸套管焊接處靠車輪一側(cè) Tresca 應(yīng)力最大，其最大應(yīng)力值如表 A3 所示。表 A2 該驅(qū)動橋橋殼在五種工況下的最大應(yīng)力汽車 2.5 倍滿載靜止時汽車滿載以最大牽引力行駛時汽車滿載緊急制動時汽車滿載轉(zhuǎn)彎時汽車滿載轉(zhuǎn)彎制動時危險斷面應(yīng)力(MPa) 175 87 93.5 158 205鋼板沖壓焊接橋殼許用應(yīng)力 400 MPa，由表 2 可以看出該橋殼在 5 中工況下的應(yīng)力都遠(yuǎn)小于橋殼的許用應(yīng)力，證明該設(shè)計很安全。圖 A3 為該驅(qū)動橋橋殼在汽車以最大牽引力行使工況下板簧座附近的應(yīng)力分布圖。經(jīng)本系統(tǒng)分析該汽車驅(qū)動橋橋殼前 9 階自振頻率如表 A3 所示。表 A3 該汽車驅(qū)動橋橋殼前 9 階自振頻率Order 1 2 3 4 5 6 7 8 9Frequency 181.47 265.91 433.24 614.33 658.76 1119.9 1166 1347.4 1399.610由于路面不平度引起的汽車振動頻率多在 1-20Hz，所以不會由路面激振引起橋殼的共振，該橋殼結(jié)果比較合理。圖 A4 為該橋殼在一階自振頻率下的振形。圖 A3 汽車 2.5 倍滿載靜止工況下板簧座附近應(yīng)力分布圖圖 A4 橋殼在一階自振頻率下的振形