SolidWorks運(yùn)動(dòng)仿真培訓(xùn)

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1、COSMOSMotion 運(yùn)動(dòng)仿真培訓(xùn),COSMOSMotion 2008,,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)使用方法 A note about files配套光盤(pán)說(shuō)明 Conventions used in this book本書(shū)中采用的原理 Class Introductions課程介紹,,,COSMOSWorks,Design Validation Products設(shè)計(jì)仿真產(chǎn)品,,,Vibration & Buckling,What is Mo

2、tion 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)研究 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)械連接 The mass and 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 (Mo

3、tors 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(lèi)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)制運(yùn)動(dòng)下的部件動(dòng)作 Fully controlled and only one possible motion result irrespective of force and mass 不考慮力和質(zhì)量的全約束和單一運(yùn)動(dòng)的結(jié)果 Zero degree of freedom 零自由度 Dynami

4、c System動(dòng)力學(xué)系統(tǒng) Movement of part(s) under free motion subject to forces 自由運(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(lài)于力 的部分約束和無(wú)限數(shù)量的結(jié)果 Greater than zero degrees of freedom 自由度數(shù)大于零,Understanding Basics運(yùn)動(dòng)基礎(chǔ),,Mass and Inertia質(zhì)量和慣性 Newtons First Law牛頓第一定律 Co

5、nservation of momentum動(dòng)力守恒 Degrees of freedom自由度 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)上的特定自由度的限制 Mechanical joints 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)

6、動(dòng)的連接 Joint motion運(yùn)動(dòng)副 Gravity重力,,,,,x,y,,Pendulum restrained to pivot about mounting point,Mapping 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 mates. 100多種定義SolidWorks配合的方法 Basic constraint types are merg

7、ed to simplified mechanical joints. 基礎(chǔ)約束類(lèi)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)正交同軸配合轉(zhuǎn)化為一個(gè)轉(zhuǎn)動(dòng)副 One Point to Point coincident mate in SolidW

8、orks 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)幅的形式?；镜募s束類(lèi)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 translational joint 3 orthogonal coincident joints bec

9、omes a fixed joint 1 Coincident and 1 orthogonal concentric becomes a revolute joint 所有的裝配約束被映射為連接，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) 。這些是共有的連接。,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)行運(yùn)動(dòng)分析？,程序在每一個(gè)時(shí)間步都應(yīng)用修正的Newton-Raphson迭代法進(jìn)行運(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)間步的下一個(gè)時(shí)間步的位置 仿真求解必須滿(mǎn)足以下要求： 零件的速度 零件間

10、的配合關(guān)系 力和加速度 結(jié)果會(huì)一直迭代計(jì)算直到達(dá)到該時(shí)間步上的力和加速度值的某一精度為止。,運(yùn)動(dòng)副基礎(chǔ)知識(shí)（1）,Revolute鉸接副,約束2個(gè)旋轉(zhuǎn)，3個(gè)移動(dòng)自由度,Cylindrical圓柱副,約束2個(gè)旋轉(zhuǎn)，2個(gè)移動(dòng)自由度,運(yùn)動(dòng)副基礎(chǔ)知識(shí)（2）,Translational 移動(dòng)副,Spherical球形副,約束3個(gè)旋轉(zhuǎn)，2個(gè)移動(dòng)自由度,約束3個(gè)移動(dòng)自由度,運(yùn)動(dòng)副基礎(chǔ)知識(shí)（3）,Planar平面副,Universal萬(wàn)向副,約束1個(gè)旋轉(zhuǎn)，3個(gè)移動(dòng)自由度,約束2個(gè)旋轉(zhuǎn)， 1個(gè)移動(dòng)自由度,運(yùn)動(dòng)副基礎(chǔ)知識(shí)（4）,Fixed固定副,Screw螺旋副,約束3個(gè)旋轉(zhuǎn)，3個(gè)移動(dòng)自由度,約束1個(gè)自由度

11、,2個(gè)構(gòu)件可以不平行于移動(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。,運(yùn)動(dòng)副基礎(chǔ)知識(shí)（5）,Parallel平行軸,約束構(gòu)件1的Z軸，始終平行于構(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)自由度,Perpendicular垂直軸,約束構(gòu)件1的Z軸，始終垂直于構(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)自由度,運(yùn)動(dòng)副基礎(chǔ)知識(shí)（6）,In Line點(diǎn)在直線(xiàn)上,約束構(gòu)件1的連接點(diǎn)，只能沿著構(gòu)件2連接點(diǎn) 標(biāo)記的Z軸運(yùn)動(dòng),約束2個(gè)移動(dòng)自由度,In Plane點(diǎn)在面內(nèi),約束3個(gè)旋轉(zhuǎn)自由度,約束2個(gè)構(gòu)件之間的相對(duì)轉(zhuǎn)動(dòng),運(yùn)動(dòng)副基礎(chǔ)知識(shí)（7）,Orientation方向,

12、約束3個(gè)旋轉(zhuǎn)自由度,約束2個(gè)構(gòu)件之間的相對(duì)轉(zhuǎn)動(dòng),CosmosMotion機(jī)構(gòu)基礎(chǔ),剛性實(shí)體： 1、 在Motion中，所有構(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)變形或改變形狀。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狀態(tài)：固定或靈活。 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）在一起，如果它們也是單一零件。,CosmosMotion機(jī)構(gòu)基礎(chǔ),固定零件 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)自由度 固定零

13、件承擔(dān)為運(yùn)動(dòng)剛性實(shí)體的參考結(jié)構(gòu) SolidWorks中，裝配體中的固定零件會(huì)自動(dòng)地被處理為固定構(gòu)件，在開(kāi)始一個(gè)新的機(jī)構(gòu)和映射裝配體約束時(shí)。,CosmosMotion機(jī)構(gòu)基礎(chǔ),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)自由度。 SolidWorks中，裝配體中的浮動(dòng)零件會(huì)自動(dòng)地被處理為活動(dòng)構(gòu)件，在開(kāi)始一個(gè)新的機(jī)構(gòu)和映射裝配體約束時(shí)。,CosmosMotion機(jī)構(gòu)基礎(chǔ),配合 SolidWorks配合充分定義剛性構(gòu)件如何連接以及它們之間如何相互運(yùn)動(dòng)。配合從零件的連接中移除自由度。 在兩個(gè)剛性構(gòu)件中添加配合，例如同軸配合，就移走了自由度，致使它們相對(duì)于其它構(gòu)件保持定位，即使機(jī)構(gòu)

14、中存在運(yùn)動(dòng)或作用力。,CosmosMotion機(jī)構(gòu)基礎(chǔ),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)基礎(chǔ),重力 當(dāng)零件的重量對(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，例如自由落體。 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(huà)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，或通過(guò)指定一個(gè)參考平面。幅值必須單獨(dú)輸入。默認(rèn)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）,CosmosMotion機(jī)構(gòu)基礎(chǔ),約束映射概念,Cosm

15、osMotion機(jī)構(gòu)基礎(chǔ),力 當(dāng)在CosmosMotion中定義各種力時(shí)，必須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(xiàn)和面。,User Interface用戶(hù)界面,總結(jié),,Lesson 1第1課,Car Jack 汽車(chē)千斤頂,,Lesson 1: Topics內(nèi)容,Introduction to the COSMOSMotion Feature Manager COSMOSMotion特征管理器介紹 Understand basic capabilities of COSMOSMotion COSMOSMotion的基本能

16、力 Run a Simulation 運(yùn)行仿真 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(lèi)型選項(xiàng)框,3、Motion特征管理器,4、動(dòng)畫(huà)和特征時(shí)間線(xiàn),5、MotionManager工具條,Lesson1:模型說(shuō)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)

18、備的裝置。最常見(jiàn)的樣式是轎車(chē)千斤頂，地板千斤頂、車(chē)庫(kù)千斤頂，用以提升汽車(chē)，以方便維修。轎車(chē)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(chē)。更強(qiáng)大的千斤頂使用液壓動(dòng)力可以提供更遠(yuǎn)距離的舉升。機(jī)械千斤頂通常以最大提升能力分級(jí)（例如1.5噸或3噸等）,Lesson 1:Simulation Goal 仿真目標(biāo),,Lesson 1：Analysis Step分析步驟（1）,1、 Open the assembly：to open the assembly file Car_Jack.sldasm from the Lesson01 folder. 打開(kāi)裝配體： Car_Jack.sldasm（ 文件夾L

19、esson01） 2 、Change 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 研究類(lèi)型 5 、Run the Animation for 5 seconds. 運(yùn)行一個(gè)5秒的動(dòng)畫(huà) 6 、Run the Animation for 8 seconds 運(yùn)行一個(gè)8秒的動(dòng)畫(huà) 7 、Rename the Assembly Simulation study 重命名裝配體算例,Lesson 1：Analys

20、is Step分析步驟（2）,8 Duplicate the 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作為研究類(lèi)型 11 Apply Gravity to the assembly 應(yīng)用重力到裝配體 12 Create a contact condition betwee

21、n SprocketLink3 and SprocketLink4. 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(chē)重量作用在

22、千斤頂上。,Lesson 1：Analysis Step分析步驟（3）,15 Run the Simulation for 8 seconds. 運(yùn)行一個(gè)8秒的仿真 16 Plot the torque required to lift the weight of the car. 輸出提升汽車(chē)重量所需的扭矩 17 Plot the power consumed to lift a weight of 2000 lbs. 輸出提升2000lbs重量所需消耗的功率 18 Rotate assembly 轉(zhuǎn)動(dòng)裝配體 19 Play the animation. 播放動(dòng)畫(huà) 20 Enabl

23、e View Key Creation. 激活視窗鍵創(chuàng)建 21 Create a new view key. 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(huà),Lesson 1：Analysis Step分析步驟,24 Save and close assembly. 保存和關(guān)閉裝配體,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

24、約束 Joints運(yùn)動(dòng)副 Joint Primitives基本副 Cam Constraints凸輪約束 Forces Applied Forces施加力 Flexible Connectors 連接柔性處理 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)行一個(gè)8秒的動(dòng)畫(huà),計(jì)算按鈕,時(shí)間線(xiàn),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(lèi)的視覺(jué)屬性融合到運(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)?？墒褂?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

25、運(yùn)動(dòng)算例使用 MotionManager，此為基于時(shí)間線(xiàn)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核心包內(nèi)使用）。您可使用裝配體運(yùn)動(dòng)來(lái)動(dòng)畫(huà)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)。 使用設(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)使用插值來(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核心包內(nèi)使用）。您可使用物理模擬在裝配體上模仿馬達(dá)、彈簧、碰撞、以及引力。物理模擬在計(jì)算運(yùn)動(dòng)時(shí)考慮到質(zhì)量。物理模擬計(jì)算相當(dāng)塊，所以您可將之用來(lái)生成使用基于物理的模擬的演示性動(dòng)畫(huà)。

26、 COSMOSMotion（可在 SolidWorks office premium 中使用。）您可使用 COSMOSMotion 在裝配體上精確模擬和分析模擬單元的效果（包括力、彈簧、阻尼、以及摩擦）。COSMOSMotion 使用計(jì)算能力強(qiáng)大的動(dòng)力求解器，在計(jì)算中考慮到材料屬性和質(zhì)量及慣性。您也可使用 COSMOSMotion 為進(jìn)一步分析標(biāo)繪模擬結(jié)果。,決定使用哪種算例類(lèi)型,使用裝配體運(yùn)動(dòng)為不需要考慮到質(zhì)量或引力的運(yùn)動(dòng)生成演示性動(dòng)畫(huà)。 使用物理模擬生成考慮到質(zhì)量、碰撞、或引力的運(yùn)動(dòng)的演示性近似模擬。 使用 COSMOSMotion 運(yùn)行考慮到裝配體運(yùn)動(dòng)的物理特性的計(jì)算能力強(qiáng)大的模

27、擬。該工具為以上三種選項(xiàng)中計(jì)算能力最強(qiáng)的。您對(duì)所需的運(yùn)動(dòng)的物理特性理解越深，則您的結(jié)果越佳。您可使用 COSMOSMotion 運(yùn)行沖擊分析算例以了解零部件對(duì)各種不同力的響應(yīng)。,MotionManager 工具,模擬單元,解算器沒(méi)能收斂?？赡茉蚴?,1.解算器沒(méi)能取得指定的精度。松弛COSMOSMotion屬性中的精度設(shè)定。 2.如果模型中的零件快速移動(dòng)，經(jīng)常評(píng)估雅可比值。 3.機(jī)制可能已鎖定。以不同的初始配置開(kāi)始模擬或者更改您的馬達(dá)以獲得有效的運(yùn)動(dòng)。 4.如果在模擬開(kāi)始時(shí)就出現(xiàn)故障，使用較小的初始積分器步長(zhǎng)大小。 5.嘗試使用一嚴(yán)格解算器，如WSTIFF。 6.嘗試在模型中避免激烈斷續(xù)性，

28、如突然運(yùn)動(dòng)變化，力變化或啟用/禁用配合。 7.您可能在使用速度極高的馬達(dá)。嘗試降低馬達(dá)速度。 8.確定任何時(shí)候只有一個(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),,Lesson 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 回顧C(jī)OSMOSMotion中基本運(yùn)動(dòng)副類(lèi)型 Understand Automatic Constraint mapping 理解自動(dòng)約束映射 Apply moti

29、on 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 mates 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

30、 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(xiàn)連接,Lesson 2: Results結(jié)果,,,Collar-1 not only translates along collar_shaft-1 but also rotates. Collar-1（軸套）不僅沿collar_shaft-1（滑動(dòng)軸）移動(dòng)同時(shí)還繞軸轉(zhuǎn)動(dòng)。 The rotation needs to be prevented 轉(zhuǎn)動(dòng)必須消除,Lesson 2: Motion on Joints,,

31、Lesson 2: Results結(jié)果,Power Consumption in Mechanism 機(jī)構(gòu)的能量消耗,Why is Power Consumption negative in some places? 為什么在某些位置能量消耗為負(fù)值？,Lesson 3,Piston Crankshaft Mechanism 活塞曲柄機(jī)構(gòu),,Lesson 3 Topics內(nèi)容,Review basic joint types in COSMOSMotion COSMOSMotion基本運(yùn)動(dòng)副回顧 Create Mechanical Joints 建立機(jī)械副 Apply motion to a

32、joint 為運(yùn)動(dòng)副添加運(yùn)動(dòng) Create and review results 創(chuàng)建和瀏覽結(jié)果,,Lesson 3: Basic Joint Types,,,Joints used to constrain the relative motion of a pair of rigid bodies by physically connecting them. 物理連接的一對(duì)剛性體應(yīng)用機(jī)械副約束相對(duì)運(yùn)動(dòng) Joint Primitives used to enforce standard geometric constraints 虛約束應(yīng)用于強(qiáng)化標(biāo)準(zhǔn)幾何約束,Lesson 4,Door Me

33、chanism 門(mén)開(kāi)關(guān)機(jī)構(gòu),,Lesson 4 Topics內(nèi)容,,Create springs and damper 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 spri

34、ngs and dampers to achieve desired design goals 修改彈簧和阻尼器，實(shí)現(xiàn)設(shè)定的設(shè)計(jì)目標(biāo),Lesson 4 Attaching Parts,,Physically 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連接到一起 No relative motion between the two parts 消除兩零件間的相對(duì)運(yùn)動(dòng) Initial orientation

35、 between the two parts will be locked and will be maintained throughout the simulation 鎖定兩零件的原始定位，并在仿真求解中保持定位,1#實(shí)體,2#實(shí)體,Lesson 4: Springs彈簧,,Translational Spring Force（線(xiàn)性彈簧力） = -k (X - X0)n + F0 Where（這里）: k = Spring stiffness coefficient (always 0)彈簧剛度系數(shù)（總是0) X = Current distance between the spring

36、 connection points X0 = Reference length of the spring (Free length) 彈簧參考長(zhǎng)度（自由長(zhǎng)度） n = Exponent 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.正向力分離物體 Negative force attracts the two parts.負(fù)向力拉近物體,Similar force expressio

37、n applies to Torsional Springs 近似表達(dá)式可用于扭轉(zhuǎn)彈簧,Lesson 4: Dampers緩沖器,,Translational Damper Force（線(xiàn)性阻尼力） = c*vn Where（此處）: c - Translational damping coefficient 線(xiàn)性阻尼系數(shù) v - Current relative velocity between parts at the attachment points 零件在連接點(diǎn)上的相對(duì)速度 n - Exponent. 指數(shù),Similar force expression applies to

38、 Torsional Dampers 近似表達(dá)式可用于扭轉(zhuǎn)緩沖器,Lesson 4: Results結(jié)果,,gas_piston-1 not only translates along gas_cylinder-1 but also rotates. 活塞沿缸體既移動(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 速度目標(biāo)應(yīng)該滿(mǎn)足： Door does not stop in 30 seconds 門(mén)應(yīng)該不在30秒內(nèi)停下。,Should we increa

39、se or decrease spring stiffness? 應(yīng)該減小還是增加彈簧剛度？,Spring stiffness 彈簧剛度: 1 N/mm Damper Co-efficient阻尼系數(shù): 5 N (sec/mm),Lesson 4: Results,,,Velocity goal is satisfied Door stops in 30 seconds 速度目標(biāo)滿(mǎn)足門(mén)在30秒內(nèi)停下,,Spring stiffness彈簧剛度: 2 N/mm Damper Co-efficient阻尼系數(shù): 10 N (sec/mm),Lesson 5,Hatchback Mechanism

40、后尾箱開(kāi)啟機(jī)構(gòu),,Lesson 5 Topics目標(biāo),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 修改零件的質(zhì)量特性 Use Impact forces to control two parts from interfering each other 使用沖擊力控制零件間的相互干涉,,Affect the dynamic behavior of a mechanism 模仿機(jī)構(gòu)的動(dòng)力學(xué)行為 Do not prohibit or prescribe moti

41、on 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(xiàn)和扭轉(zhuǎn)彈簧 Translational and Torsional Dampers 直線(xiàn)和扭轉(zhuǎn)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柔性連接 Gravity重

42、力,Lesson 5: Forces力,,Force Type力類(lèi)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 cylindrical surface. 使用邊線(xiàn)，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(xiàn)定義 Magnitude幅值 Enter a pre-defined function expression (

43、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. 使用內(nèi)置的庫(kù)函數(shù)在函數(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,,移動(dòng)過(guò)度：活塞在氣缸外,移動(dòng)正確：活塞在氣缸內(nèi),Less

44、on 5: Impact Forces沖擊力,,Intermittent force that is dependent on relative distance between two components). 依賴(lài)于兩元件相對(duì)距離的間歇力 Impact forces are used to simulate the collision between two parts. 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 forc

45、e specified by the impact parameters is applied to both of the colliding parts. 當(dāng)兩零件接近在指定的距離內(nèi)時(shí)，沖擊力成為主動(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 bodies colliding. 碰撞依賴(lài)于材料和碰撞的幾何體形狀,Impact Force = Spring Force + Damping Force 沖擊力=彈簧力+阻尼力 Stiffness: Depends

46、on material properties and curvature of interacting surfaces 剛度：依賴(lài)于材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：模擬碰撞的能量消耗 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

47、 impact force is activated (parts contact) 長(zhǎng)度：沖擊力是主動(dòng)力時(shí)的距離（零件接觸）,Lesson 5: Impact Parameters碰撞參數(shù),,Impact Force = Spring Force + Damping Force Stiffness: Depends on material properties and curvature of interacting surfaces Exponent: Determines impact force characteristic Max Damping: Simulates energy

48、loss in collision Penetration: Depth at which maximum damping occurs. Length: distance at which the impact force is activated (parts contact),Lesson 5: Impact Parameters,,Good numbers for impact parameters: 碰撞參數(shù)最佳數(shù)值： Stiffness剛度: 10000 lb/in10000 N/mm Exponent指數(shù): 1.1-1.3 1.1-1.3 Damping阻尼:0.1-100 lb

49、-s/in1-100 Penetration穿透: 0.0001 in0.01 mm,Lesson 5: Impact Parameters碰撞參數(shù),,d cannot be specified as 0 D不能設(shè)定為0,Lesson 5: Results結(jié)果,,Translational displacement of the concentric joint between the piston and cylinder parts 活塞和氣缸間的同軸副的直線(xiàn)位移,Notice that the displacement is held at 8 inches which means th

50、at the impact force does not allow further translation between the parts 注意：當(dāng)位移保持在8英寸時(shí)，兩零件間的沖擊力不再允許更深的移動(dòng)。,Lesson 5: Results結(jié)果,,Magnitude of the impact force applied 沖擊力幅值,Lesson 6,Latching Assembly 鎖緊機(jī)構(gòu),,,Point-curve - Restricts a point on one rigid body to lie on a curve on a second rigid body. 點(diǎn)-線(xiàn)

51、：約束一剛性體的點(diǎn)作用在另一剛性體的邊線(xiàn)上 Curve-curve - Constrains one curve to remain in contact with a second curve. 線(xiàn)-線(xiàn)：約束一條與第二條曲線(xiàn)保持接觸 Intermittent curve-curve - Applies a force to prevent curves from penetrating each other. Only active if the parts are touching 線(xiàn)-線(xiàn)間歇接觸：施加一個(gè)力防止曲線(xiàn)相互穿越，只有在零件接觸時(shí)起效。 3D Contact Applies a

52、 force to prevent bodies from penetrating each other. Only active if the parts are touching 3D接觸：施加一個(gè)力防止實(shí)體間相互穿透。只有在零件接觸時(shí)起效。,Lesson 6: Understanding Contacts 理解接觸,,Contact is similar to an impact force in that the material properties of the parts are used to define the contact parameters. 接觸類(lèi)似于在有

53、沖擊力作用時(shí)，通過(guò)零件的材料屬性來(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(xiàn)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 Contacts 沖擊力與接觸的比較,,Lesson 6: 3D Contact 3D 接觸,

54、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 精確幾何體 Longer simulation time but produces accurate results 仿真求解時(shí)間長(zhǎng)，但結(jié)果較精確,Lesson 7,

55、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)致不精確的求解,Lesson 7: Redundancies約束冗余,Symmetrically located mates report different force magnitudes. 對(duì)稱(chēng)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 incorrect solution. 柔

56、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 mates,,Model with optimum stiffness Flexible mates with correct optimum stiffness provide correct dynamic solution. 最佳剛度模型-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 8,,Excavator,Lesson 8,Excavator.sldasm,定義固定和可動(dòng)的零件,挖土機(jī)的練習(xí),定義Swing Tower的運(yùn)動(dòng)

57、,Parts Branch,Find Swing Tower joint to add motion to,Double 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 Displacement Set Function: to Expression,Define Boom Motion,F

58、ind revolute joint between swing tower and boom,Motion 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 Displacement Set Function: to Expression,Define Extended Boom Motion,Motion Function: STEP(TIME,0, 0d, 1, 40d)+STEP(TIME,1, 0

59、d, 2.5, -70d)+STEP(TIME,4, 0d, 5, 70d)+STEP(TIME,5, 0d, 6, -40d),挖土機(jī)的練習(xí),Set Motion Type: to Displacement Set Function: to Expression,,,Define Bucket Motion,Motion 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 wi

60、th Motion,,Right click on joint and select Properties,Click on Properties tab and change name,Under the Joints branch, new names should appear,,挖土機(jī)的練習(xí),,,Simulation Parameters,Run Simulation,挖土機(jī)的練習(xí),Plot Driving Motion Torque,,Select Rotary Motion Generator as the quantity and Magnitude as the value,,

61、,Drag joints with motion onto XY Plots,挖土機(jī)的練習(xí),Driving Motion Results,挖土機(jī)的練習(xí),常用函數(shù),在Motion中使用adams的函數(shù)，函數(shù)比較多，大概有11種之多，如 1、Displacement Function 2、Velocity Functions 3、 Acceleration Functions 4、 Contact Functions 5、 Spline Functions 6、 Force in Object Functions 7、Resultant Force Functions 8、 Math Functi

62、ons 9、 Data Element Access 10、User-Written Subroutine Invocation 11、Constants & Variables。5、bistop函數(shù)它的格式是BISTOP( x, dx, x1, x2, k, e, cmax, d)這里它由八個(gè)參數(shù)定義。它與函數(shù)IMPACT類(lèi)似?？梢赃@么說(shuō)：BISTOP是雙側(cè)碰撞函數(shù)，而IMPACT是單側(cè)碰撞函數(shù)。BISTOP的觸發(fā)是由兩個(gè)邊界條件確定的，即x1和x2，當(dāng)x值大于或等于x1且小于或等于x2時(shí)，函數(shù)值為0，當(dāng)x值大于x2或小于x1時(shí)，它的值是不同的。當(dāng)x小于x1時(shí)，返回值是：k(x1-x)e-c

63、max*dx*step(x,x1-d,1,x1,0)，當(dāng)x大于x2時(shí)，返回值是：k(x-x2)e-cmax*dx*step(x,x2,1,x2+d,0)。各種參數(shù)表示意義可以從IMPACT里推出來(lái)，它只是多了一個(gè)x2。,1、 STEP函數(shù),格式：STEP (x, x0, h0, x1, h1) 參數(shù)說(shuō)明： x自變量，可以是時(shí)間或時(shí)間的任一函數(shù) x0 自變量的STEP函數(shù)開(kāi)始值，可以是常數(shù)或函數(shù)表達(dá)式或設(shè)計(jì)變量； x1 自變量的STEP函數(shù)結(jié)束值，可以是常數(shù)、函數(shù)表達(dá)式或設(shè)計(jì)變量 h0 STEP函數(shù)的初始值，可以是常數(shù)、設(shè)計(jì)變量或其它函數(shù)表達(dá)式 h1 STEP函數(shù)的最終值，可以是常數(shù)、設(shè)計(jì)變量或

64、其它函數(shù)表達(dá)式,IF函數(shù),2、 IF函數(shù)格式：IF(表達(dá)式1: 表達(dá)式2, 表達(dá)式3, 表達(dá)式4)參數(shù)說(shuō)明：表達(dá)式1ADAMS的評(píng)估表達(dá)式；表達(dá)式2如果的Expression1值小于0，IF函數(shù)返回的Expression2值；表達(dá)式3如果表達(dá)式1的值等于0，IF函數(shù)返回表達(dá)式3的值；表達(dá)式4如果表達(dá)式1的值大于0，IF函數(shù)返回表達(dá)式4的值；例如：函數(shù) IF(time-2.5:0,0.5,1)結(jié)果： 0.0 if time 2.5,3、AKISPL函數(shù),格式：AKISPL (First Independent Variable, Second Independent Variable，Splin

65、e Name, Derivative Order) 參數(shù)說(shuō)明： First Independent Variable spline中的第一個(gè)自變量Second Independent Variable (可選) spline中的第二自變量 Spline Name 數(shù)據(jù)單元spline的名稱(chēng) Derivative Order (可選) 插值點(diǎn)的微分階數(shù)，一般用0就可以function = AKISPL(DX(marker_1, marker_2, marker_2), 0, spline_1) spline_1用下表中的離散數(shù)據(jù)定義自變量x函數(shù)值y-4.0 -3.6 -3.0 -2.5 -2.0

66、 -1.2 -1.0 -0.4 0.0 0.0 1 0.4 2 1.2 3 2.5 4 3.6,4、碰撞函數(shù)impact,其實(shí)質(zhì)是：用只抗壓縮的非線(xiàn)性的彈簧阻尼方法近似計(jì)算出單邊碰撞力。格式：IMPACT (Displacement Variable, Velocity Variable, Trigger for Displacement Variable, Stiffness Coefficient, Stiffness Force Exponent, Damping Coefficient, Damping Ramp-up Distance) 參數(shù)說(shuō)明： Displacement Variable 實(shí)時(shí)位移變量值，通過(guò)DX、DY、DZ、DM等函數(shù)實(shí)時(shí)測(cè)量。 Velocity Variable 實(shí)時(shí)速度變量值，通過(guò)VX、VY、VZ、VM等函數(shù)實(shí)時(shí)測(cè)量。 Trigger for Displacement Variable 激發(fā)碰撞力的位移測(cè)量值。 Stiffness Coefficient or K 剛度系統(tǒng)。 Stiffness Force Exponent 非線(xiàn)性彈簧力指數(shù)。 Da