1 Oscillating Slider Estimated time required: 25 min GUI familiarity level required: Higher MSC.ADAMS 2005 r2

2 Topics 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

3 Oscillating 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.

4 If you are successful, you should end up with a ADAMS model that illustrates an oscillating slider mechanism. What You Should Accomplish

5 Creating 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

6 Create 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

7 Modify 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 b c d e f

8 Rotate 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.)

9 Modify 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= 0.0C2 = 0.0C3 = 0.0 A1 = 180.0A2 = 90.0A3 = b c f d e

10 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 Joint f e d c b a

11 Create 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 c g

12 Creating 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

13 This is what your screen should look like when your model is completeModel

14 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 Model

15 Theoretical Solution ADAMS solutionResults Acceleration = ~706 in/sec^2

16 In this tutorial you learned how to: Topics Covered 1.Create a 2 Body 2 Location Translational Joint 2.Modify Joint Motion 3.Modify Orientation of a Joint 4.Create a frustum

17 Best 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.