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Homework Help: 2DOF problem with one mass

  1. May 4, 2012 #1
    1. The problem statement, all variables and given/known data
    I need some help with the following problem:

    System shown has m=5, k1=100, k2=150, and c=2

    Find the natural frequencies, damping ratios, and mode shapes.

    The figure of the system has been attached.

    2. Known Equations
    I know how to find natural frequencies, damping ratios, and mode shapes, my only issue is actually setting up the M, K and C matrices as I have only seen multiple degree of freedom problems with more than one mass, and with all of the springs at 90 degree angles. I am not sure how I am supposed to work this one out.

    3. Work attempted
    I have attempted at setting up this problem twice but I know I am doing it wrong because when I calculate my M^-.5*K*M^-.5 Matrix it does not exist, or it gives me non real numbers as eigenvalues (eg. x=42.6 + or - 17.2603i). Any help setting up the problem would be appreciated.

    Attached Files:

  2. jcsd
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