ADAMS Assignment 4

ME451:Kinematics and Dynamics of Machine Systems

Turning in Your Assignment

Create a single PDF file, named “lastName_ADAMS_04.pdf” with the information listed on the last slide (including the supporting plots).

Make sure your name is listed on that file. Drop the file in the appropriate Dropbox Folder (ADAMS_04)

at Learn@UW

You will need to download “link_geometry.zip” file to complete this tutorial. This file is available for download on the class website.

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Webcutter

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This tutorial will describe in depth how to use ADAMS to determine the torque of the motor, bearing forces, and the angular position, velocity, and acceleration of the links for the given problem.

Links are 2cm thick and made out of Al 6063. Link 2 is rotating at a rate of 60 rpm CCW.

Problem Title

O2

A2

B3

O4

B4

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If you are successful, you should end up with a simple working webcutter model that illustrates bearing force, motor torque and angular

velocity/acceleration of your model.

What You Should Accomplish

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Getting Started:a. Create a New Modelb. IMPORTANT: Verify that the Units text field is set to MKS - m,kg,N,s,deg.

Create New Model

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To edit the grid size:a. Click Settings menu, select Working Grid…The Working Grid Settings window will appearb. Change the Spacing text fields in X and Y to (10mm)c. Click OKd. Click View Coordinate Window (F4)

a

c

b

Change Working Grid Settings

Note: you should see a denser set of dots on your screen

d

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Set Material Properties

a. Click Build Menu Materials New b. A new window will appear, enter:

Name: .Webcutter.Al6063

Young Modulus: 214e6

Poissons Ratio: 0.33

Density: 2710

c. Click OK

Note: If the density is not set the simulation will not run properly

a

b

c

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Create Extruded Part

a. Right click on Rigid body tool stack, select Extrusion tool

b. Enter 2cm in the Length text field

c. Select Backward from Path: drop down menu

d. Click points origin (0.0, 0.0, 0.0) (0.15, 0.15 0.0) (0.15, 0.0, 0.0) (0.0, 0.0, 0.0), right-click to close

Note: When using a command the bar on the bottom will tell you what to do and you can always exit a command by pressing the Esc key

b

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Rename

a. Right-Click on part, select Part: PART_2 Rename

b. Enter .model_1.link_2 in New Name text field

c. Click OK

d. Rename the Marker at the origin to .model_1.O2

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Modify Extrusion Points

a. Right-click on the triangle, select Extrusion: Extrusion_1 Modify.

b. Click next to Profile Points text field

c. Click Read button next to File

d. Browse the directory for the file link2.txt

e. Click Open

f. Click OK

g. Click OK

NOTE: units in text file are meters!

Note: hit the “z” key to toggle zoom in/out

Note: By starting our Triangle at the origin and normalizing the points about O2 for link 2, the origin and O2 coincide.

a

b

c

d

f

eg

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Create a Marker

a. Right click on Rigid body tool stack, select Marker tool

b. Select Add to Part from Marker pull down menu

c. Select Global XY from Orientation pull down menu

d. Click Part_2 (0.04, 0.0, 0.0) NOTE: It’s a bit difficult to get the correct location on the part. Alternatively, place the marker anywhere after adding it to the part, then modify the marker’s position after it has been created

e. Rename Marker .model_1.A2

Note: This is why the links were rotated to make OA horizontal for the input files.

a

b

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Add Revolute Joint

a. Right click Joint tool stack, select Revolute joint

b. Select 1 Location from Construction pull down menu

c. Click on any marker at the origin

a

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Add Motion

a. Right Click on Motion Driver tool stack, select Rotational Joint Motion

b. Enter (360D) in Speed text field

c. Click JOINT_1

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a. In the lower right corner of the modeling window, right-click on the Information icon. b. Click on the Verification icon. 

The Info Window appearsc. After seeing that the model has verified successfully, d. click on the Close button

a

b

c

d

Verify Your Model

Note: The model verification step is one way to find errors in the model definition. ADAMS checks for error conditions such as misaligned joints, unconstrained parts, or massless parts in dynamic systems, and alerts you to other possible problems in the model.

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How to simulate the model:a. Click on the Simulation tool in the Toolbox.b. Select Duration from pull down menuc. Enter 2d. Select Step Size from pull down menue. Enter 0.01f. Click on the Play button. 

If everything has been done correctly the bar should complete two full revolutions.

a

Run a Simulation

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Save Database

a. Save your database by Click File Save Database, and select no for a backup copy

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Create Part 2

a. Create another extruded triangle, with thickness = 0.2, using points:

(0.04, 0.0, 0.0) (0.3, 0.0, 0.0) (0.25, -0.15, 0.0)

b. Modify Extrusion points using list3.txt

c. Rename the part to link_3

d. Create Marker at Point (0.32,0.0,0.0), rename it B3

e. Create a revolute joint (2 bodies, 1 location) between link_2 and link_3 at marker A2, (0.04, 0, 0)

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Revolve Part

a. Click anywhere on Link 3. Notice that everything is highlighted and there is a green handle at the end of the y axis on the coordinate located at A2.

b. Click on this handle and drag left. This causes Link 3 to rotate about that point. Put Link 3 in this position for now so it is out of the way.

ab

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Verify and Simulate

a. Verify your model

b. Run a simulation: Duration = 2.0, Step Size = 0.01 

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Create Marker

a. Create Marker on the ground at point (0.26, -0.04, 0.0) NOTE: After clicking on the marker icon, you can right-click anywhere on the screen to manually enter the location

b. Rename it O4

a

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Create Part 4

a. Draw another triangle with the Extrusion tool this time with the first point at O4. Repeat the previous steps and read in Link4.txt to correct the shape.

b. Create a marker on link 4 at position (0.66, -.04, 0.0), rename it B4

c. Add a Revolute Joint between link 4 and Ground, at O4.

bc

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Create Joint between Part 3 and 4

a. Rotate link_4 so that points B3 and B4 are close

b. Click the revolute joint tool

c. Select 2 Bod-2 Loc from Construction pull down menu

d. Click link_4 link_3 (point) B4 (point) B3

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Rendering Model

a. Click View Render Mode Smooth Shaded (or Shift + S )

b. Isometric view (Shift + I)

c. Back to front view (Shift + F)

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Note: The warning is stating that the two reference points of the revolute joint are not the same and need to be the same for the part to run. ADAMS will move the two links so that the points will coincide before running the simulation.

Save Assembled Model

a. To join these location click Simulate tab Interactive Controls

b. Click which performs initial conditions solution.

c. Ignore and Close the warning that comes up. The part is now joined

d. Click

e. Enter .Webcutter_Asm in New Model text field, Click OK

f. Click play to run the simulation.

b

d

e

f

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Modify Material Properties, Create Material

a. Right-Click link 2, Select Part: link_2 Modify

b. Right Click the “Material Type” window, MaterialCreate

c. A new window will appear, enter:

Name: .Webcutter.Al6063

Young Modulus: 214e6

Poissons Ratio: 0.33

Density: 2710

d. Enter Al6063 in Material Type text field

e. Click Apply to update the material values

f. Repeat this step for link_3 and link_4.

Note: If you choose the option of just entering density, the Links will have significant deformation during the run.

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Measure Motor Torque

a. Right Click Motion and select Motion: Motion_1 Measure

b. Enter .Webcutter_Asm.Torque in Measure Name text field

c. Select Torque from Characteristic pull down menu

d. Choose Z radio button next to Component.

e. Click OK (A measurement window will appear which will graph torque respective to the simulation

a

b

c

d

e

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Measure Bearing Forces

1. Right Click on revolute joint, Select Joint: JOINT_1 Measure

2. Enter .Webcutter_Asm.Bearing_Force_1 in Measure Name text field

3. Select Force from Characteristic pull down menu

4. Choose mag radio button next to Component.

5. Click OK

a

b

c

d

e

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Measure Angles of Links with Respect to Ground

a. Click Design Exploration tab Orientation Measure

b. Select .Webcutter_Asm.link_2_O2 for To Marker (Marker on Link 2)

c. Select .Webcutter_Asm.ground.MARKER_4 for From Marker (Marker on the Ground)

d. Click OK

b

c

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Measure Angular Velocity and Acceleration

a. Right Click link_3, Select Part: link_4 Measure

b. Enter Webcutter_Asm.Ang_Acceleration

c. Choose CM Angular Acceleration select Z

d. Press Apply

e. Enter Webcutter_Asm.Ang_Velocity

f. Choose CM Angular Velocity select Z

g. Press OK

a

b

c

d

e

f

g

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Results

To create and view plots

• Click Review Postprocessing (F8)

A new window will open

• Select all measure and Click Add curves.

b

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a. Click File Export Table.

b. Enter Webcutter in File Name text field

c. Select plot_1 (or whichever plot you are trying to export) in Plot text field

d. Select spreadsheet from Format pull down menu

e. Click OK

f. Rename file from Webcutter.tab to Webcutter.xls

Export Data to Excel

a

bc

d

e

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What to turn in

a. Measure the max motor torque at the joint where the motion is applied (use z component)

a. Include a plot of the motor torque for at least 1 revolute

b. Measure the max bearing force in the two joints attached to ground

a. Include a plot for both joints

c. Plot angular velocity and angular acceleration of all the links (z component)

a. Create one plot for the angular velocities – post on the forum

b. Create one plot for the angular accelerations - post on the forum

d. Include all your plots in a single document