summary_absorber_frf

summary_absorber_frf - Summary – FRFs and Time...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Summary – FRFs and Time History for a Two DOF System The transfer function for block 1 for the two ­DOF shown below: + + x1 x2 K k f(t) M m C c has been shown to have the form (for M = m , C = c and K = k ): X1 ( s ) ms 2 + cs + k G (s) = = 2 F (s) ms 2 + 2 cs + 2 k ms 2 + cs + k − ( cs + k ) ( )( ) For harmonic input f ( t ) = F0 sinω t , the steady ­state response for block 1 can be written in terms of its amplitude and phase frequency response functions (FRFs) as: x1, ss ( t ) = F0 G ( jω ) sin (ω t + ∠G ( jω )) The movie that follows presents the amplitude FRF G ( jω ) vs. ω (shown as a log log plot) and the time history x1, ss ( t ) over a range of excitation frequencies ω . As you view this movie consider the following three frequencies and the response near those frequencies: • The amplitude FRF G ( jω ) demonstrates peaks for two frequencies. These two peaks occur at two frequencies (known as the resonant frequencies) that are near the imaginary parts of the poles of the transfer function. The time history shows a large amplitude of response around the resonant frequencies. • The amplitude FRF G ( jω ) demonstrates a minimum for a frequency (known as the anti resonant frequency) between the two resonant frequencies. This anti ­resonant frequency is near the imaginary part of the zeros of the transfer function. The time history shows very small amplitude of response near the anti ­resonance. ...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern