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Oscillating Slider

Estimated time required: 25 min

GUI familiarity level required: Higher

MSC.ADAMS 2005 r2

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Topics CoveredTopics Covered

If you have any difficulties, import the “oscillator_slider_shortcut.cmd” file and proceed from pg 9

If you have any difficulties, import the “oscillator_slider_complete.cmd” file and proceed from pg 13

In this tutorial, you will learn how to:

1. Create a 2 Body 2 Location Translational Joint

2. Modify Joint Motion

3. Modify Orientation of a Joint

4. Create a frustum

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Oscillating Slider ProblemOscillating Slider Problem

The rod A is held at the constant angle beta = 30 degrees while it rotates about the vertical with constant angular rate of 120 rev/min. Simultaneously, the slider P oscillates along the rod with a variable distance from

the fixed pivot O given in inches by R=8+2sin2pint, where the frequency n of oscillation along the rod is a constant 2 cycles per second and where the time t is in seconds. Calculate the magnitude of the acceleration of

the slider for an instant when its velocity R-dot along the rod is a maximum.

This problem asks for the magnitude of acceleration of the slider at the instant its velocity along the rod is at a maximum. We will use ADAMS to create a model with the given conditions and collect the data needed.

Problem 2/239 from J. L. Meriam and L. G. Kraige, Engineering Mechanics: Volume 2, Dynamics 3rd edition. John Wiley & Sons, Inc.

Copyright © 1992, by John Wiley & Sons, Inc.

This material is used by permission of John Wiley & Sons, Inc.

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If you are successful, you should end up with a ADAMS model that illustrates an oscillating slider mechanism.

What You Should AccomplishWhat You Should Accomplish

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Creating the ModelCreating the Model

a. Start ADAMS.

b. Create a new model. (Model Name = oscillator, Units = ips, Gravity = none)

c. Resize the working grid, Size = X – 75i, Y – 50i, Spacing X – 1i, Y – 1i

d. Create a Cylinder ( Length =16i and Radius = .25i). Click once on the origin and once along the y axis. A 16 inch long rod is created. Rename .oscillator.ROD

e. Create a Sphere on the center of the ROD, Radius =1i, rename .oscillator.SLIDER

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Create a Translational JointCreate a Translational Joint

a. Select Translational joint from joint tool stack

b. Select 2 Bod-2 Loc from Construction drop down menu

c. Click ROD SPHERE ROD.cm ROD.MARKER_1 MARKER_2.Y CYLINDER_1.E1

a

b

c

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Modify Translational Joint MotionModify Translational Joint Motion

a

a. Right click the translational joint , Select Joint: JOINT_1 Modify

b. Click Impose Motion(s).

c. In the Tra Z row, select disp(time)= under Type,

d. Under f(time), enter the following string: 8+2*sin(4*pi*time)

e. Click OK

f. Click OK

bc d

ef

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Rotate ModelRotate Model

Select the entire model and rotate it 30 degrees clockwise. (Drag with the left mouse button to create highlight box, and use the Position tool to rotate the model.)

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Modify Orientation of a Revolute JointModify Orientation of a Revolute Joint

a. Create a revolute joint between the ground and ROD

b. Right-click revolute joint, select Joint: JOINT_2 Modify

c. Click Change Position Icon

d. Enter:

e. Click OK

f. Click OK

C1= 0.0 C2 = 0.0 C3 = 0.0

A1 = 180.0 A2 = 90.0 A3 = 180.0

b

c

f

d

e

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a. Right click the revolute joint , Select Joint: JOINT_2 Modify

b. Click Impose Motion(s).

c. In the Rot Z row, select disp(time)= under Type,

d. Under f(time), enter the following string: (120*2*pi/60) * time

e. Click OK

f. Click OK

Add Motion to a Revolute JointAdd Motion to a Revolute Joint

f e

dc

b

a

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Create a FrustumCreate a Frustum

a. Select Frustum tool from Rigid Body tool stack

b. Select On Ground from Frustum pull down menu

c. Turn on Length checkbox and enter (16 * COS(30))

d. Turn on Bottom Radius checkbox and enter (.1)

e. Turn on Top Radius checkbox and enter (16 * SIN(30))

f. Click on the origin

g. Click in the positive Y - dir

a

b

d

f

e

cg

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Creating MeasureCreating Measure

a. Right-click SPHERE, select Part: SPHERE Measure

b. Select CM acceleration from Characteristic pull down menu, and set the Component to mag.

c. Click Apply

d. Select CM velocity from Characteristic drop down menu, and set the Component to Z

e. Enter the marker on the rod that was used to define the translational joint for both the Represent coordinates

in and Do time derivatives in

a. Click OK

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This is what your screen should look like whenyour model is complete

ModelModel

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a. Verify your model

b. Run a simulation (end time = 0.5, steps = 50)

c. Transfer the small graph to a full plot in the ADAMS plotting screen. (right mouse button inside small plotting window)

d. Use the Display Plot Statistics tool to follow the plot curve. Find the value for Y when X = 0.0

Testing the ModelTesting the Model

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Theoretical Solution ADAMS solution

ResultsResults

Acceleration = ~706 in/sec^2

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In this tutorial you learned how to:

Topics CoveredTopics Covered

1. Create a 2 Body 2 Location Translational Joint

2. Modify Joint Motion

3. Modify Orientation of a Joint

4. Create a frustum

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Best PracticesBest Practices

• Make sure correct units are set to ips and the viewing area is zoomed in or out enough to see the model. It may be helpful to set the working grid to "1i" spacing under the Settings menu.

• Make sure gravity is turned off.

• Make sure the revolute joint is in the y direction.

• Check dimensions of the part to make sure they are correct.

• Make sure the measures are set correctly.

• Make sure the plot is displaying the correct set of results.

• Make sure there are enough output steps to observe the angular velocity of AB and BC at the correct time.