GUI familiarity level required: Higher Crate on Incline Plane with Friction and Initial Velocity Estimated time required: 15 min GUI familiarity level required: Higher MSC.ADAMS 2005 r2

Topics Covered In this tutorial, you will learn how to: Add friction to a translational joint Change friction input forces If you have any difficulties, import the “Crate_on_incline_plane_level.cmd” file and proceed from pg 6 If you have any difficulties, import the “Crate_on_incline_plane_15_deg.cmd” file and proceed from pg 7 If you have any difficulties, import the “Crate_on_incline_plane_30_deg.cmd” file and proceed from pg 7

(a) theta = 15 degrees (b) theta = 30 degrees Incline Plane Problem The 50-kg crate is projected along the floor with an initial speed of 7 m/s at x=0. The coefficient of kinetic friction is 0.4. Calculate the time required for the crate to come to rest and the corresponding distance x traveled. Now the crate is projected down an incline as shown with an initial speed of 7 m/s. Investigate the time t required for the crate to come to rest and the corresponding distance x traveled if: (a) theta = 15 degrees (b) theta = 30 degrees Problems 3/4 and 3/5 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.

What You Should Accomplish If you are successful, you should end up with a ADAMS model that shows the effect of friction on a crate’s total distance traveled at different angles.

Creating the Model Start ADAMS. Create a new model. (Model Name = Crate_on_incline_plane, Units = mmks, Gravity = -y earth) Create crate part. (box, length = 20 cm, height = 15 cm, depth = 20 cm, mass = 50 kg, rename .Crate_on_incline_plane.CRATE) Create a translational joint with friction between crate and ground plane (mu kinetic = 0.4) Set the velocity initial condition for the crate to 7 m/s in the X-direction in the crate's coordinate frame. Create a measure for displacement of the crate.

Test Model Run simulation. (Duration = 2.0, Step Size = 0.01) Open full screen plot of displacement vs. time and observe the plot where displacement becomes constant (crate comes to rest). Record the time and displacement of this event.

Modify and Test Model The problem calls for the entire model to be rotated. Select both the crate and the translational joint and use the rotate tool to rotate them 15 degrees. Run another simulation. (Duration = 6.0, Step Size = 0.01) Repeat for a 30 degree slope. (Duration = 20.0, Step Size = 0.1) Observe effects of incline at each angle theta.

This is what your screen should look like when Model This is what your screen should look like when your model is complete.

Theoretical Solution ADAMS solution Results level surface: x = 6.24 m, t = 1.78 seconds 15 degree slope: x = 19.58 m, t = 5.59 seconds 30 degree slope: crate does not come to rest level surface: 15 degree slope: x = 19.58 m, t = 5.59 seconds 30 degree slope: crate actually accelerates, never comes to rest The plot illustrates an exponential curve that shows that the crate will never come to rest

Topics Covered In this tutorial you learned how to: Add friction to a translational joint Change friction input forces

Best Practices Make sure correct units are set to mmks. Make sure gravity is on. Check mass of crate to make sure it is correct. It may need to be set manually. Check dimensions of parts. Make sure the initial velocity is applied in the x direction relative to the crate and not ground. Make sure the measures are set correctly. After model is rotated, displacement will be in both the x and y direction, so measure the total magnitude. Make sure the plot is displaying the correct set of results. Make sure there are enough output steps to observe the effect at each angle setting.