1、COSMOSMotion 運(yùn)動(dòng)仿真培訓(xùn)About this course關(guān)于本課程Prerequisites前提條件Course Design Philosophy課程設(shè)計(jì)原理Using this book本書(shū)運(yùn)用方法A note about files配套光盤闡明Conventions used in this book本書(shū)中采用的原理Class Introductions課程引見(jiàn)COSMOSWorksAdv. ProfessionalProfessionalDesign Validation Products設(shè)計(jì)仿真產(chǎn)品DesignerStaticVibration & BucklingT

2、hermalDrop TestFatigueNonlinearPost-dynamicsCOSMOSEMSElectromagneticCOSMOSMotionCOSMOSFloWorksFlow SimulationOptimizationWhat is Motion Simulation 什么是運(yùn)動(dòng)仿真?Study of moving systems or mechanisms運(yùn)動(dòng)系統(tǒng)或機(jī)構(gòu)研討Motion of a system is determined by 運(yùn)動(dòng)系統(tǒng)定義：Mechanical joints connecting the parts 零件的機(jī)械銜接The mass a

3、nd inertia properties of the components 部件的質(zhì)量和慣性特性Applied forces to the system (Dynamics) 系統(tǒng)的作用力動(dòng)力學(xué)Driving motions (Motors or Actuators) 驅(qū)動(dòng)運(yùn)動(dòng)運(yùn)動(dòng)或致動(dòng)器Time 時(shí)間Mechanism types機(jī)構(gòu)類型Kinematic System運(yùn)動(dòng)學(xué)系統(tǒng)Movement of part(s) under enforced or constrained motion 外加或強(qiáng)迫運(yùn)動(dòng)下的部件動(dòng)作Fully controlled and only one possib

4、le motion result irrespective of force and mass 不思索力和質(zhì)量的全約束和單一運(yùn)動(dòng)的結(jié)果Zero degree of freedom 零自在度Dynamic System動(dòng)力學(xué)系統(tǒng)Movement of part(s) under free motion subject to forces 自在運(yùn)動(dòng)物體與力作用下的零件運(yùn)動(dòng)Partially controlled and infinite number of results depending on forces 依賴于力 的部分約束和無(wú)限數(shù)量的結(jié)果Greater than zero degrees

5、 of freedom 自在度數(shù)大于零Understanding Basics運(yùn)動(dòng)根底Mass and Inertia質(zhì)量和慣性Newtons First Law牛頓第一定律Conservation of momentum動(dòng)力守恒Degrees of freedom自在度Rigid body剛性物體Grounded parts固定零件Moving parts運(yùn)動(dòng)零件Constraints約束Restrictions placed on a parts movement in specific degrees of freedom 作用在零件運(yùn)動(dòng)上的特定自在度的限制Mechanical join

6、ts are connections that restrict the movement of one part to another機(jī)械關(guān)節(jié)是約束零件相互運(yùn)動(dòng)的銜接Joint motion運(yùn)動(dòng)副Gravity重力xyPendulum restrainedto pivot about mountingpointMapping of SolidWorks assembly mates (constraints) to COSMOSMotion joints. 映射SolidWorks裝配體配合約束為COSMOSMotion的運(yùn)動(dòng)副100+ ways of defining SolidWorks

7、 mates. 100多種定義SolidWorks配合的方法Basic constraint types are merged to simplified mechanical joints. 根底約束類型合并為簡(jiǎn)化的機(jī)械約束One Orthogonal Concentric mate in SolidWorks becomes a Concentric joint.一個(gè)正交同軸配合轉(zhuǎn)化為同軸副 One Coincident and One Orthogonal Concentric mates in SolidWorks becomes a Revolute joint.一個(gè)重合和一個(gè)正交同

8、軸配合轉(zhuǎn)化為一個(gè)轉(zhuǎn)動(dòng)副 One Point to Point coincident mate in SolidWorks becomes a spherical joint一個(gè)點(diǎn)對(duì)點(diǎn)重合配合轉(zhuǎn)化為一個(gè)球副。Constraint Mapping約束映射約束映射什么是約束映射?是指在2個(gè)指定的零件之間，自動(dòng)地、智能的將裝配關(guān)系轉(zhuǎn)化為最小的機(jī)構(gòu)運(yùn)動(dòng)幅的方式。根本的約束類型可以合并為簡(jiǎn)單的機(jī)構(gòu)運(yùn)動(dòng)幅，例如 e.g. 1 coincident joints becomes a planar joint 2 orthogonal coincident joints becomes a translatio

9、nal joint 3 orthogonal coincident joints becomes a fixed joint 1 Coincident and 1 orthogonal concentric becomes a revolute joint一切的裝配約束被映射為銜接，包括曲面和曲面的約束 (如： 圓柱面/平面相切、圓柱面/圓柱面相切) 。這些是共有的銜接。映射的約束注:SolidWorks 中有100多種零件約束的方式計(jì)算機(jī)如何進(jìn)展運(yùn)動(dòng)分析？程序在每一個(gè)時(shí)間步都運(yùn)用修正的Newton-Raphson迭代法進(jìn)展運(yùn)算采用很小的時(shí)間步，軟件就會(huì)預(yù)測(cè)零件相對(duì)于原始條件或當(dāng)前時(shí)間步的下一

10、個(gè)時(shí)間步的位置仿真求解必需滿足以下要求： 零件的速度 零件間的配合關(guān)系 力和加速度 結(jié)果會(huì)不斷迭代計(jì)算直到到達(dá)該時(shí)間步上的力和加速度值的某一精度為止。 運(yùn)動(dòng)副根底知識(shí)1原點(diǎn)方向Revolute鉸接副約束2個(gè)旋轉(zhuǎn)，3個(gè)挪動(dòng)自在度構(gòu)件1構(gòu)件2Cylindrical圓柱副約束2個(gè)旋轉(zhuǎn)，2個(gè)挪動(dòng)自在度運(yùn)動(dòng)副根底知識(shí)2原點(diǎn)方向原點(diǎn)y-axisx-axisz-axisTranslational 挪動(dòng)副Spherical球形副約束3個(gè)旋轉(zhuǎn)，2個(gè)挪動(dòng)自在度約束3個(gè)挪動(dòng)自在度運(yùn)動(dòng)副根底知識(shí)3銜接點(diǎn)軸 1軸 2原點(diǎn)方向Planar平面副Universal萬(wàn)向副約束1個(gè)旋轉(zhuǎn)，3個(gè)挪動(dòng)自在度約束2個(gè)旋轉(zhuǎn)， 1個(gè)挪動(dòng)自

11、在度運(yùn)動(dòng)副根底知識(shí)4原點(diǎn)Fixed固定副Screw螺旋副約束3個(gè)旋轉(zhuǎn)，3個(gè)挪動(dòng)自在度約束1個(gè)自在度2個(gè)構(gòu)件可以不平行于挪動(dòng)和旋轉(zhuǎn)軸，但2個(gè)構(gòu)件的Z軸應(yīng)該平行且方向一致。挪動(dòng)和旋轉(zhuǎn)軸螺距運(yùn)動(dòng)副根底知識(shí)5原點(diǎn)方向 1st Axis 2nd AxisParallel平行軸約束構(gòu)件1的Z軸，一直平行于構(gòu)件2的Z軸即構(gòu)件1只能繞構(gòu)件2的一個(gè)軸旋轉(zhuǎn)約束2個(gè)旋轉(zhuǎn)自在度Perpendicular垂直軸約束構(gòu)件1的Z軸，一直垂直于構(gòu)件2的Z軸即：構(gòu)件1只能繞構(gòu)件2的二個(gè)軸旋轉(zhuǎn)約束1個(gè)旋轉(zhuǎn)自在度運(yùn)動(dòng)副根底知識(shí)6銜接點(diǎn)方向銜接點(diǎn)指定的面X參考軸In Line點(diǎn)在直線上約束構(gòu)件1的銜接點(diǎn)，只能沿著構(gòu)件2銜接點(diǎn)標(biāo)志的Z

12、軸運(yùn)動(dòng)約束2個(gè)挪動(dòng)自在度In Plane點(diǎn)在面內(nèi)約束3個(gè)旋轉(zhuǎn)自在度約束2個(gè)構(gòu)件之間的相對(duì)轉(zhuǎn)動(dòng)運(yùn)動(dòng)副根底知識(shí)7Orientation方向約束3個(gè)旋轉(zhuǎn)自在度約束2個(gè)構(gòu)件之間的相對(duì)轉(zhuǎn)動(dòng)CosmosMotion機(jī)構(gòu)根底剛性實(shí)體： 1、 在Motion中，一切構(gòu)件都被作為理想剛體。意味著零件內(nèi) 部沒(méi)有變形，在仿真過(guò)程中構(gòu)件不會(huì)變形或改動(dòng)外形。一個(gè)剛性構(gòu)件可以是單一的SolidWorks零件或子裝配體。 2、SolidWorks零件或子裝配體的兩種形狀：固定或靈敏。 3、一個(gè)剛性的子裝配體就是指組成子裝配體的獨(dú)立部件被剛性地相互附加焊接在一同，假設(shè)它們也是單一零件。CosmosMotion機(jī)構(gòu)根底固定零件

13、一剛性零件可被當(dāng)作固定構(gòu)件或浮動(dòng)運(yùn)動(dòng)的零件。固定零件就是絕對(duì)靜止。每一固定的實(shí)體都具有0個(gè)自在度固定零件承當(dāng)為運(yùn)動(dòng)剛性實(shí)體的參考構(gòu)造SolidWorks中，裝配體中的固定零件會(huì)自動(dòng)地被處置為固定構(gòu)件，在開(kāi)場(chǎng)一個(gè)新的機(jī)構(gòu)和映射裝配體約束時(shí)。CosmosMotion機(jī)構(gòu)根底浮動(dòng)零件機(jī)構(gòu)中可以運(yùn)動(dòng)的部件被當(dāng)作是活動(dòng)構(gòu)件。每個(gè)活動(dòng)構(gòu)件有六個(gè)自在度。SolidWorks中，裝配體中的浮動(dòng)零件會(huì)自動(dòng)地被處置為活動(dòng)構(gòu)件，在開(kāi)場(chǎng)一個(gè)新的機(jī)構(gòu)和映射裝配體約束時(shí)。CosmosMotion機(jī)構(gòu)根底配合SolidWorks配合充分定義剛性構(gòu)件如何銜接以及它們之間如何相互運(yùn)動(dòng)。配合從零件的銜接中移除自在度。在兩個(gè)剛性構(gòu)

14、件中添加配合，例好像軸配合，就移走了自在度，致使它們相對(duì)于其它構(gòu)件堅(jiān)持定位，即使機(jī)構(gòu)中存在運(yùn)動(dòng)或作用力。CosmosMotion機(jī)構(gòu)根底電機(jī)電機(jī)可為零件定義在一個(gè)時(shí)間段內(nèi)的運(yùn)動(dòng)。電機(jī)可定義位移，速度，或作為時(shí)間函數(shù)的加速度。CosmosMotion機(jī)構(gòu)根底重力當(dāng)零件的分量對(duì)運(yùn)動(dòng)仿真有影響時(shí)，重力是一個(gè)非常重要的數(shù)量，例如自在落體。重力有兩部分組成： 重力矢量方向 重力加速度的幅值重力屬性對(duì)話框可以指定方向和重力矢量值，可以在對(duì)應(yīng)的文本框內(nèi)輸入x,y,z方向的值，或經(jīng)過(guò)指定一個(gè)參考平面。幅值必需單獨(dú)輸入。默許的重力矢量值為0，-1，0，幅值為386.22in/s2(或與當(dāng)前激活單位的當(dāng)量值Cos

15、mosMotion機(jī)構(gòu)根底約束映射概念CosmosMotion機(jī)構(gòu)根底力當(dāng)在CosmosMotion中定義各種力時(shí)，必需指定力的位置和方向。這些位置和方向可以從選定的SolidWorks實(shí)體中派生出來(lái)。實(shí)體可以是草圖點(diǎn)，頂點(diǎn)，邊線和面。User Interface用戶界面總結(jié)Lesson 1第1課Car Jack汽車千斤頂Lesson 1: Topics內(nèi)容Introduction to the COSMOSMotion Feature Manager COSMOSMotion特征管理器引見(jiàn)Understand basic capabilities of COSMOSMotion COSMOS

16、Motion的根本才干Run a Simulation 運(yùn)轉(zhuǎn)仿真Create a result plot 創(chuàng)建結(jié)果輸出Cosmosmotion界面1、SolidWorks特征樹(shù)2、運(yùn)動(dòng)類型選項(xiàng)框3、Motion特征管理器4、動(dòng)畫和特征時(shí)間線5、MotionManager工具條Lesson1:模型闡明A mechanical jack is a device that lifts heavy equipment. The most common form is a car jack, floor jack, or garage jack which lifts vehicles so that

17、maintenance can be performed. Car jacks usually use mechanical advantage to allow a human to lift a vehicle. More powerful jacks use hydraulic power to provide more lift over greater distances. Mechanical jacks are usually rated for a maximum lifting capacity (e.g., 1.5 tons or 3 tons).機(jī)械千斤頂是提升重型設(shè)備的

18、安裝。最常見(jiàn)的款式是轎車千斤頂，地板千斤頂、車庫(kù)千斤頂，用以提升汽車，以方便維修。轎車千斤頂通常借助機(jī)械優(yōu)勢(shì)讓一個(gè)人就可提升汽車。更強(qiáng)大的千斤頂運(yùn)用液壓動(dòng)力可以提供更遠(yuǎn)間隔的舉升。機(jī)械千斤頂通常以最大提升才干分級(jí)例如1.5噸或3噸等Lesson 1:Simulation Goal 仿真目的Lesson 1：Analysis Step分析步驟11、 Open the assembly：to open the assembly file Car_Jack.sldasm from the Lesson01 folder. 翻開(kāi)裝配體： Car_Jack.sldasm 文件夾Lesson012 、Ch

19、ange to the Motion Study. 切換到運(yùn)動(dòng)算例3 、Create a Motor that drives the Screw_rod at 5 RPM 創(chuàng)建電機(jī)，驅(qū)動(dòng)絲杠：5rpm.4 、Type of Study 研討類型5 、Run the Animation for 5 seconds. 運(yùn)轉(zhuǎn)一個(gè)5秒的動(dòng)畫6 、Run the Animation for 8 seconds 運(yùn)轉(zhuǎn)一個(gè)8秒的動(dòng)畫7 、Rename the Assembly Simulation study 重命名裝配體算例Lesson 1：Analysis Step分析步驟28 Duplicate th

20、e Assembly motion study to create a new Motion Study 復(fù)制裝配體算例創(chuàng)建一個(gè)新的運(yùn)動(dòng)算例9 Ensure that COSMOSMotion is added in 啟動(dòng)COSMOSMotion插件10 Select COSMOSMotion as the Type of study 選擇COSMOSMotion作為研討類型11 Apply Gravity to the assembly 運(yùn)用重力到裝配體12 Create a contact condition between SprocketLink3 and SprocketLink4.

21、 在SprocketLink3 和 SprocketLink4.間設(shè)定接觸條件13 Create similar contact condition between SprocketLink1 and SprocketLink2. SprocketLink1和 SprocketLink2之間創(chuàng)建一個(gè)同樣的接觸條件14 Create a force of 2000 lbs to simulate the weight of the car on the car jack. 創(chuàng)建一個(gè)2000lbs的力，以模擬汽車分量作用在千斤頂上。Lesson 1：Analysis Step分析步驟315 Run

22、 the Simulation for 8 seconds. 運(yùn)轉(zhuǎn)一個(gè)8秒的仿真16 Plot the torque required to lift the weight of the car. 輸出提升汽車分量所需的扭矩17 Plot the power consumed to lift a weight of 2000 lbs. 輸出提升2000lbs分量所需耗費(fèi)的功率18 Rotate assembly 轉(zhuǎn)動(dòng)裝配體19 Play the animation. 播放動(dòng)畫20 Enable View Key Creation. 激活視窗鍵創(chuàng)建21 Create a new view key

23、. 建立一個(gè)新的視窗鍵22 Reorient the view 定位視窗23 Play the animation 播放動(dòng)畫Lesson 1：Analysis Step分析步驟24 Save and close assembly. 保管和封鎖裝配體Lesson 1: Defining and Simulating a Mechanism第1課：定義和仿真一個(gè)機(jī)構(gòu)Parts部件Moving Parts運(yùn)動(dòng)部件Ground Parts固定部件Constraints約束Joints運(yùn)動(dòng)副Joint Primitives根本副Cam Constraints凸輪約束ForcesApplied Force

24、s施加力Flexible Connectors 銜接柔性處置Gravity重力Results結(jié)果添加電機(jī)折疊運(yùn)動(dòng)管理器添加馬達(dá)運(yùn)轉(zhuǎn)一個(gè)8秒的動(dòng)畫計(jì)算按鈕時(shí)間線關(guān)鍵碼備注： 運(yùn)動(dòng)算例簡(jiǎn)介 運(yùn)動(dòng)算例是裝配體模型運(yùn)動(dòng)的圖形模擬。您可將諸如光源和相機(jī)透視圖之類的視覺(jué)屬性交融到運(yùn)動(dòng)算例中。運(yùn)動(dòng)算例不更改裝配體模型或其屬性。它們模擬并動(dòng)作給模型規(guī)定的運(yùn)動(dòng)。可運(yùn)用 SolidWorks 配合在您建模運(yùn)動(dòng)時(shí)約束零部件在裝配體中的運(yùn)動(dòng)。可從運(yùn)動(dòng)算例運(yùn)用 MotionManager，此為基于時(shí)間線的界面，包括有以下運(yùn)動(dòng)模擬工具：裝配體運(yùn)動(dòng)物理模擬COSMOSMotion比較裝配體運(yùn)動(dòng)可在 SolidWorks中心

25、包內(nèi)運(yùn)用。您可運(yùn)用裝配體運(yùn)動(dòng)來(lái)動(dòng)畫裝配體的運(yùn)動(dòng)：添加馬達(dá)來(lái)驅(qū)動(dòng)裝配體一個(gè)或多個(gè)零件的運(yùn)動(dòng)。運(yùn)用設(shè)定鍵碼點(diǎn)在不同時(shí)間規(guī)定裝配體零部件的位置。裝配體運(yùn)動(dòng)運(yùn)用插值來(lái)定義鍵碼點(diǎn)之間裝配體零部件的運(yùn)動(dòng)。 物理模擬可在 SolidWorks中心包內(nèi)運(yùn)用。您可運(yùn)用物理模擬在裝配體上模擬馬達(dá)、彈簧、碰撞、以及引力。物理模擬在計(jì)算運(yùn)動(dòng)時(shí)思索到質(zhì)量。物理模擬計(jì)算相當(dāng)塊，所以您可將之用來(lái)生成運(yùn)用基于物理的模擬的演示性動(dòng)畫。COSMOSMotion可在 SolidWorks office premium 中運(yùn)用。您可運(yùn)用 COSMOSMotion 在裝配體上準(zhǔn)確模擬和分析模擬單元的效果包括力、彈簧、阻尼、以及摩擦。C

26、OSMOSMotion 運(yùn)用計(jì)算才干強(qiáng)大的動(dòng)力求解器，在計(jì)算中思索到資料屬性和質(zhì)量及慣性。您也可運(yùn)用 COSMOSMotion 為進(jìn)一步分析標(biāo)繪模擬結(jié)果。決議運(yùn)用哪種算例類型 運(yùn)用裝配體運(yùn)動(dòng)為不需求思索到質(zhì)量或引力的運(yùn)動(dòng)生成演示性動(dòng)畫。 運(yùn)用物理模擬生成思索到質(zhì)量、碰撞、或引力的運(yùn)動(dòng)的演示性近似模擬。 運(yùn)用 COSMOSMotion 運(yùn)轉(zhuǎn)思索到裝配體運(yùn)動(dòng)的物理特性的計(jì)算才干強(qiáng)大的模擬。該工具為以上三種選項(xiàng)中計(jì)算才干最強(qiáng)的。您對(duì)所需的運(yùn)動(dòng)的物理特性了解越深，那么您的結(jié)果越佳。您可運(yùn)用 COSMOSMotion 運(yùn)轉(zhuǎn)沖擊分析算例以了解零部件對(duì)各種不同力的呼應(yīng)。MotionManager 工具模擬單

27、元解算器沒(méi)能收斂。能夠緣由是:1.解算器沒(méi)能獲得指定的精度。松弛COSMOSMotion屬性中的精度設(shè)定。 2.假設(shè)模型中的零件快速挪動(dòng)，經(jīng)常評(píng)價(jià)雅可比值。 3.機(jī)制能夠已鎖定。以不同的初始配置開(kāi)場(chǎng)模擬或者更改您的馬達(dá)以獲得有效的運(yùn)動(dòng)。 4.假設(shè)在模擬開(kāi)場(chǎng)時(shí)就出現(xiàn)缺點(diǎn)，運(yùn)用較小的初始積分器步長(zhǎng)大小。 5.嘗試運(yùn)用一嚴(yán)厲解算器，如WSTIFF。 6.嘗試在模型中防止猛烈斷續(xù)性，如忽然運(yùn)動(dòng)變化，力變化或啟用/禁用配合。 7.您能夠在運(yùn)用速度極高的馬達(dá)。嘗試降低馬達(dá)速度。 8.確定任何時(shí)候只需一個(gè)馬達(dá)在驅(qū)動(dòng)某一零部件。Lesson 2第2課Slider Crank Mechanism滑塊曲柄機(jī)構(gòu)Le

28、sson 2: Topics內(nèi)容Create moving and ground parts 建立運(yùn)動(dòng)和固定部件Review basic joint types in COSMOSMotion 回想COSMOSMotion中根本運(yùn)動(dòng)副類型Understand Automatic Constraint mapping 了解自動(dòng)約束映射Apply motion to a joint 給運(yùn)動(dòng)副添加運(yùn)動(dòng)Create a result plot 創(chuàng)建結(jié)果輸出Lesson 2: Constraint Mapping Concept 約束映射概念1 Coincident and 1 concentric m

29、ates becomes a revolute joint 一個(gè)重合和同軸配合轉(zhuǎn)化為轉(zhuǎn)動(dòng)副1 Concentric mate becomes a cylindrical joint 一個(gè)同軸配合轉(zhuǎn)化為圓柱副A point on a point coincident mate becomes a spherical joint 一個(gè)點(diǎn)對(duì)點(diǎn)的重合配合轉(zhuǎn)化為球副A point on an axis coincident mate becomes an Inline Joint 軸上一點(diǎn)的重合配合轉(zhuǎn)化為在線銜接Lesson 2: Results結(jié)果 Collar-1 not only translat

30、es along collar_shaft-1 but also rotates. Collar-1軸套不僅沿collar_shaft-1滑動(dòng)軸挪動(dòng)同時(shí)還繞軸轉(zhuǎn)動(dòng)。 The rotation needs to be prevented 轉(zhuǎn)動(dòng)必需消除Lesson 2: Motion on JointsJoint Types運(yùn)動(dòng)副類型Type of motion allowed允許的運(yùn)動(dòng)類型 Available options under Motion On list應(yīng)用選項(xiàng)Cylindrical圓柱副Rotation and translation in one direction沿同一方向既移

31、動(dòng)又轉(zhuǎn)動(dòng)Rotate Z（轉(zhuǎn)動(dòng)）Translate Z（移動(dòng)）Revolute轉(zhuǎn)動(dòng)副O(jiān)nly Rotation in one direction只允許在同一方向轉(zhuǎn)動(dòng)Rotate Z（轉(zhuǎn)動(dòng)）Translational移動(dòng)副O(jiān)nly Translation in one direction只允許在同一方向移動(dòng)Translate Z（移動(dòng)）Spherical球副Rotations in all directions, No translation所有方向的轉(zhuǎn)動(dòng)，沒(méi)有移動(dòng)Rotate X（轉(zhuǎn)動(dòng)）Rotate Y（轉(zhuǎn)動(dòng)）Rotate Z（轉(zhuǎn)動(dòng)）Lesson 2: Results結(jié)果Power Consu

32、mption in Mechanism機(jī)構(gòu)的能量耗費(fèi)Why is Power Consumption negative in some places?為什么在某些位置能量耗費(fèi)為負(fù)值？Lesson 3Piston Crankshaft Mechanism活塞曲柄機(jī)構(gòu)Lesson 3 Topics內(nèi)容Review basic joint types in COSMOSMotion COSMOSMotion根本運(yùn)動(dòng)副回想Create Mechanical Joints 建立機(jī)械副Apply motion to a joint 為運(yùn)動(dòng)副添加運(yùn)動(dòng)Create and review results 創(chuàng)建和

33、閱讀結(jié)果Lesson 3: Basic Joint TypesJoints used to constrain the relative motion of a pair of rigid bodies by physically connecting them. 物理銜接的一對(duì)剛性體運(yùn)用機(jī)械副約束相對(duì)運(yùn)動(dòng)Joint Primitives used to enforce standard geometric constraints 虛約束運(yùn)用于強(qiáng)化規(guī)范幾何約束Lesson 4Door Mechanism門開(kāi)關(guān)機(jī)構(gòu)Lesson 4 Topics內(nèi)容Create springs and dampe

34、r entities in COSMOSMotion COSMOSMotion中創(chuàng)建彈簧和阻尼器Attach different parts together to move them as a single entity 綁定不同部件作為同一實(shí)體運(yùn)動(dòng)Constrain the motion of a cylindrical joint to achieve correct mechanism behavior 約束圓柱副運(yùn)動(dòng)，實(shí)現(xiàn)正確的機(jī)構(gòu)運(yùn)動(dòng)Modify springs and dampers to achieve desired design goals 修正彈簧和阻尼器，實(shí)現(xiàn)設(shè)定的設(shè)計(jì)

35、目的Lesson 4 Attaching PartsPhysically attach one part to another 物理綁定一個(gè)零件到另一個(gè)零件上Two parts will be welded or rigidly connected to one another. 兩零件被焊接或剛性銜接到一同No relative motion between the two parts 消除兩零件間的相對(duì)運(yùn)動(dòng)Initial orientation between the two parts will be locked and will be maintained throughout th

36、e simulation 鎖定兩零件的原始定位，并在仿真求解中堅(jiān)持定位1#實(shí)體2#實(shí)體Lesson 4: Springs彈簧Translational Spring Force線性彈簧力 = -k (X - X0)n + F0Where這里:k = Spring stiffness coefficient (always 0)彈簧剛度系數(shù)總是0)X = Current distance between the spring connection points X0 = Reference length of the spring (Free length) 彈簧參考長(zhǎng)度自在長(zhǎng)度n = Expo

37、nent defining spring characteristic彈簧特性定義指數(shù)F0 = Reference force of the spring (preload)參考力預(yù)緊力Positive force repels the two parts.正向力分別物體Negative force attracts the two parts.負(fù)向力拉近物體Similar force expression applies to Torsional Springs近似表達(dá)式可用于改動(dòng)彈簧Lesson 4: Dampers緩沖器Translational Damper Force線性阻尼力 =

38、c*vn Where此處:c - Translational damping coefficient 線性阻尼系數(shù)v - Current relative velocity between parts at the attachment points 零件在銜接點(diǎn)上的相對(duì)速度n - Exponent. 指數(shù)Similar force expression applies to Torsional Dampers近似表達(dá)式可用于改動(dòng)緩沖器Lesson 4: Results結(jié)果 gas_piston-1 not only translates along gas_cylinder-1 but al

39、so rotates. 活塞沿缸體既挪動(dòng)又轉(zhuǎn)動(dòng) The rotation needs to be prevented 消除轉(zhuǎn)動(dòng)Lesson 4: Results結(jié)果 Velocity goal is satisfied速度目的應(yīng)該滿足：Door does not stop in 30 seconds門應(yīng)該不在30秒內(nèi)停下。Should we increase or decrease spring stiffness?應(yīng)該減小還是添加彈簧剛度？Spring stiffness 彈簧剛度: 1 N/mmDamper Co-efficient阻尼系數(shù): 5 N (sec/mm)Lesson 4: R

40、esults Velocity goal is satisfiedDoor stops in 30 seconds速度目的滿足門在30秒內(nèi)停下Spring stiffness彈簧剛度: 2 N/mmDamper Co-efficient阻尼系數(shù): 10 N (sec/mm)Lesson 5Hatchback Mechanism后尾箱開(kāi)啟機(jī)構(gòu)Lesson 5 Topics目的Create an Action Only force to simulate 創(chuàng)建一個(gè)單作用力并仿真Change the mass properties of a part 修正零件的質(zhì)量特性Use Impact forc

41、es to control two parts from interfering each other 運(yùn)用沖擊力控制零件間的相互關(guān)涉Affect the dynamic behavior of a mechanism 模擬機(jī)構(gòu)的動(dòng)力學(xué)行為Do not prohibit or prescribe motion and so do not add or remove degrees-of-freedom from your model.Force Entities力實(shí)體Translational and Torsional Springs 直線和改動(dòng)彈簧Translational and Tor

42、sional Dampers 直線和改動(dòng)阻尼器Action-Only Forces/Moments 單作用力/力矩Action-Reaction Forces/Moments 作用-反作用力/力矩Impact Forces沖擊力Flexible Connectors柔性銜接Gravity重力Lesson 5: Forces力Force Type力類型Whether the loading is a force or a moment. 載荷是力還是力矩Location定位Direction方向Along an axis defined by an edge, plane or cylindri

43、cal surface. 運(yùn)用邊線，平面或圓柱面沿軸定義Along the line-of-sight between two points 兩點(diǎn)間沿基準(zhǔn)線定義Magnitude幅值Enter a pre-defined function expression (step, harmonic, spline).輸入預(yù)定義的函數(shù)表達(dá)式步進(jìn)，簡(jiǎn)諧，樣條Enter an equation directly into the Function Expression field using the library of built-in COSMOSMotion functions. 運(yùn)用內(nèi)置的庫(kù)函數(shù)在

44、函數(shù)表達(dá)式框內(nèi)直接輸入方程式Lesson 5: Force Definition定義力Lesson 5: Action Only Force單作用力Lesson 5: Results結(jié)果挪動(dòng)過(guò)度：活塞在氣缸外挪動(dòng)正確：活塞在氣缸內(nèi)Lesson 5: Impact Forces沖擊力Intermittent force that is dependent on relative distance between two components). 依賴于兩元件相對(duì)間隔的間歇力Impact forces are used to simulate the collision between two p

45、arts. 間歇力用于仿真兩零件的碰撞As two parts approach within a specified distance, the impact force becomes active, and a force specified by the impact parameters is applied to both of the colliding parts. 當(dāng)兩零件接近在指定的間隔內(nèi)時(shí)，沖擊力成為自動(dòng)力，沖擊參數(shù)控制的力施加在兩碰撞零件之間。The collision is dependent on the materials and geometry of the

46、bodies colliding. 碰撞依賴于資料和碰撞的幾何體外形Impact Force = Spring Force + Damping Force 沖擊力=彈簧力+阻尼力Stiffness: Depends on material properties and curvature of interacting surfaces剛度：依賴于資料屬性和接觸面的曲率Exponent: Determines impact force characteristic指數(shù)：定義沖擊力特性Max Damping: Simulates energy loss in collision最大緩沖：模擬碰撞的

47、能量耗費(fèi)Penetration: Depth at which maximum damping occurs. 穿透深度：最大阻尼發(fā)生時(shí)的深度Length: distance at which the impact force is activated (parts contact) 長(zhǎng)度：沖擊力是自動(dòng)力時(shí)的間隔零件接觸Lesson 5: Impact Parameters碰撞參數(shù)Impact Force = Spring Force + Damping ForceStiffness: Depends on material properties and curvature of intera

48、cting surfacesExponent: Determines impact force characteristicMax Damping: Simulates energy loss in collisionPenetration: Depth at which maximum damping occurs. Length: distance at which the impact force is activated (parts contact)Lesson 5: Impact ParametersGood numbers for impact parameters:碰撞參數(shù)最正

49、確數(shù)值：Stiffness剛度: 10000 lb/in10000 N/mmExponent指數(shù): 1.1-1.3 1.1-1.3 Damping阻尼:0.1-100 lb-s/in1-100 Penetration穿透: 0.0001 in0.01 mmLesson 5: Impact Parameters碰撞參數(shù)d cannot be specified as 0D不能設(shè)定為0Lesson 5: Results結(jié)果Translational displacement of the concentric joint between the piston and cylinder parts活

50、塞和氣缸間的同軸副的直線位移Notice that the displacement is held at 8 inches which means that the impact force does not allow further translation between the parts留意：當(dāng)位移堅(jiān)持在8英寸時(shí)，兩零件間的沖擊力不再允許更深的挪動(dòng)。Lesson 5: Results結(jié)果Magnitude of the impact force applied沖擊力幅值Lesson 6Latching Assembly鎖緊機(jī)構(gòu)Point-curve - Restricts a poi

51、nt on one rigid body to lie on a curve on a second rigid body.點(diǎn)-線：約束一剛性體的點(diǎn)作用在另一剛性體的邊線上Curve-curve - Constrains one curve to remain in contact with a second curve.線-線：約束一條與第二條曲線堅(jiān)持接觸Intermittent curve-curve - Applies a force to prevent curves from penetrating each other. Only active if the parts are t

52、ouching線-線間歇接觸：施加一個(gè)力防止曲線相互穿越，只需在零件接觸時(shí)起效。3D Contact Applies a force to prevent bodies from penetrating each other. Only active if the parts are touching3D接觸：施加一個(gè)力防止實(shí)體間相互穿透。只需在零件接觸時(shí)起效。Lesson 6: Understanding Contacts 了解接觸Contact is similar to an impact force in that the material properties of the part

53、s are used to define the contact parameters. 接觸類似于在有沖擊力作用時(shí)，經(jīng)過(guò)零件的資料屬性來(lái)定義接觸參數(shù)。Contact differs from an impact force since any point along a curve or geometry is used in the contact接觸不同于沖擊力，當(dāng)一個(gè)點(diǎn)沿著線或幾何體被定義為接觸時(shí)。Contact simulates friction forces between parts.接觸可以在零件間模擬摩擦力Lesson 6: Impact Forces Vs Contact

54、s 沖擊力與接觸的比較Lesson 6: 3D Contact 3D 接觸Surface Representation of parts:零件的特征面Tessellated Geometry 網(wǎng)格幾何體Faster but less accurate in certain contact situations like point to surface or multiple contacts 在某些接觸條件下速度快，但精度差，例如點(diǎn)對(duì)面接觸，多重接觸。Precise Geometry 準(zhǔn)確幾何體Longer simulation time but produces accurate resu

55、lts 仿真求解時(shí)間長(zhǎng)，但結(jié)果較準(zhǔn)確Lesson 7 Scissor lift剪式提升機(jī)Overconstrained model Redundancies may lead to inaccurate solutions. 過(guò)約束模型-冗余將導(dǎo)致不準(zhǔn)確的求解Lesson 7: Redundancies約束冗余Symmetrically located mates report different force magnitudes.對(duì)稱的定位約束產(chǎn)生不同的力幅值報(bào)告。Soft model Flexible mates with too soft settings may lead to inc

56、orrect solution.柔化模型-柔性配合，柔性設(shè)定將不會(huì)導(dǎo)致不正確的求解。Lesson 7: Flexible matesModel with optimum stiffness Flexible mates with correct optimum stiffness provide correct dynamic solution.最正確剛度模型-采用正確適宜的柔性配合可輸出正確的動(dòng)力學(xué)結(jié)果Lesson 7: Flexible mates柔性配合Lesson 8ExcavatorLesson 8Excavator.sldasm定義固定和可動(dòng)的零件挖土機(jī)的練習(xí)定義Swing Tow

57、er的運(yùn)動(dòng)Parts BranchFind Swing Tower joint to add motion toDouble click on joint common to both parts in Parts branch to modify joint in Constraints branch運(yùn)動(dòng)函數(shù): STEP(TIME, 3, 0d, 4, -90d)+ STEP(TIME, 5, 0d, 6, 90d)挖土機(jī)的練習(xí)Set Motion Type: to DisplacementSet Function: to ExpressionDefine Boom MotionFind r

58、evolute joint between swing tower and boomMotion Function: STEP(TIME, 0, 0d, 1, -20d)+ STEP(TIME, 2, 0d, 3, 35d) + STEP(TIME, 5, 0d, 6, -15d)挖土機(jī)的練習(xí)Set Motion Type: to DisplacementSet Function: to ExpressionDefine Extended Boom MotionMotion Function: STEP(TIME,0, 0d, 1, 40d)+STEP(TIME,1, 0d, 2.5, -70

59、d)+STEP(TIME,4, 0d, 5, 70d)+STEP(TIME,5, 0d, 6, -40d)挖土機(jī)的練習(xí)Set Motion Type: to DisplacementSet Function: to ExpressionDefine Bucket MotionMotion Function: STEP(TIME,0, 0d, 1, -20d)+STEP(TIME,1, 0d, 2.5, 90d)+STEP(TIME,4, 0d, 5, -75d)+STEP(TIME,5, 0d, 6, 5d)挖土機(jī)的練習(xí)Rename Joints with MotionRight click

60、on joint and select PropertiesClick on Properties tab and change nameUnder the Joints branch, new names should appear挖土機(jī)的練習(xí)Simulation ParametersRun Simulation挖土機(jī)的練習(xí)Plot Driving Motion Torque Select Rotary Motion Generator as the quantity and Magnitude as the valueDrag joints with motion onto XY Plot