Welcome to the website of ME 274 for the Fall 2008 semester. On this site you can view blog posts, add your own blog posts and add comments to existing posts. In addition to the blog are links to course material: course information, information on solution videos, exams, quizzes, homeworks and other course-related material. Direct links to the homework solution videos are also available on the left side of this page.


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Apr 10, 2008

8.130

I am having trouble with this problem. I found the basic EOM in terms of M*X_dot_dot+K*X=0. I think what I need to do next is to find the sin/cos equation for x(t) using x-0 for the amplitude (the C or S in the basic equation x(t)=Ccos(wnt)+Ssin(wnt) )... How do I go about finding this equation?
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2 comments:

Sebastien Planquois said...

I am a little confuse...do we assume the bar does not have any mass? How do you find the normal force acting at C = IC of disk?
Any has an idea?

April 10, 2008 at 8:36 PM
CMK said...

It is not clear from the problem statement. Since the authors did not give a mass for the bar, let's assume that it is negligible compared to the mass of the disk.

My suggestion is to assume no slip in setting up the EOM. Once your solve the EOM, then find the maximum x0 such that the disk does not slip by setting the friction force equal to mu_s*N.

Also when solving the EOM, you are looking for a sinusoidal response with an amplitude of x0. There are many initial conditions that will give an amplitude of response of x0. One set of initial conditions would be x(0) = x_0 and x_dot(0) = 0. I suggest using those initial conditions.

April 10, 2008 at 9:18 PM

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