Slider Bar

Statement of the problem

This slider bar problem illustrates the relative velocity and acceleration of two points on two rigid bodies. Various slider crank mechanisms require an analysis procedure similar to this slider bar. We can use the equations from class to determine the motion of this system, but it is difficult to visualize the motion of the system. Using Working Model software and the file SLIDEBAR.WM, you can simulate the motion of a slider crank system.

Exercises

Reference on the Ground

By moving the Slider or input a number in the box, set a value of angular velocity of bar 2, e.g. -2 rad/s.
Select a reference frame on the ground by clicking on one of the Ground button. If the system is out of the window, using the Scroll Bars on the left-hand side and bottom of the window to move it back.
Let the program Run for a while then stop it. What path do the particles on both bars follow? What is the relation between the signs of the angular velocity? The angular velocity of Bar 2 is constant, is the same true for Bar 1?
Click on Reset and Erase Track, then you can choose different reference frame let the program Run again.

Reference on Bar 1 (the bar with a groove).

Select a reference frame on point A by clicking on the button- Bar 1. If the system is out of the window, using the Scroll Bars to move it back.
Let the program Run for a while then stop it. What is the direction of the relative motion of point P.
Click on Reset, choose different reference frame to Run the program again.

Reference on Bar 2 (P is fixed on this bar).

Following the same procedure, you can choose Bar 2 as the reference frame. Run the program. Describe the motion of point O' relative to this frame (the one attached to Bar 2).
To describe the relative motion of O' to the Bar 2 frame, the following equation can be used:

Carefully describe each of these terms and if they are known without computation. This equation explains the simple shape of the motion of O' with respect to the frame on Bar 2 -- describe why.

Bonus

Also load the file linkage2 and run it. In this example you can see relative motion of a four bar linkage from three different reference frames. The file linkage2 can be found in the same folder as SLIDEBAR.WM on the Macs, and in the Lab on 'caen_heaven\Data|Software' [S:]/course.old/me240 folder on the PCs.

Step by Step Instructions (Macintosh) :

Run Working Model.

If the computer you are working on has Working Model on its hard drive, then you can run it directly from your hard drive.

If you don't have it on hard drive, you should get it from the net.
Click on the apple on the left-top part of the screen --> click on chooser --> click on AppleShare --> highlight umich-ENG-CAEN --> click on CAEN Load Server and click ok --> login as a guest --> click on Lab Software and click ok --> on the back ground of the screen, now there's Lab Software folder, open it --> click Software --> click Working Model 2D --> click Working Model 2D 4.0.

Open Working Model module in course folder on the net.

Click on the apple on the left-top of the screen--> click Chooser-->click Appleshare-->highlight umich-ENG-CAEN--> click on Macintosh Software--> click OK --> logon as guest-->click on COURSE_FOLDER-->a folder entitled COURSE_FOLDER will appear on your desktop. Open this folder-->open the CoE Course folder-->double click on ME240-->double click on SLIDEBAR.WM

Step by Step Instructions (PC) :

Run Working Model.

To start Working Model, click on the Start button using the left mouse button-->go to Programs-->Engineering & Science-->Working Model 2D 4.0

Open Working Model module in course folder on the net.

To load the module for this problem, do the following.
On Working Model menu, click File --> Open.