Mechanical Vibrations 31 - Forced Vibrations of SDOF Systems 3 (Harmonic Excitations)

[@josuemanuelparejacontreras3443]

Hi, thanks for your lectures, I have one question. At 4:00 why you use W and not W_n for the right hand side of the x(t) equation??that equation with sine and cosine looks like a general solution for an undamped system.

[@aker333aker]

because you are (at that moment) only looking at the particular solution (X_p). And you want that to be in the general form of the right hand side of you ODE (F(t)). As F(t) is a function of w and nog w_n, you use w

[@Marksmetolla1]

At 14:00 you wrote that omega=1 a1=inf, this confused me a little. In my head a1=inf+ when omega-> 1- and a1=inf- when omega->1+, can you please correct me.

[@miguelcacarin6315]

at the minute 12:25 in the a2 equation , I think you made a mistake in a2 in the numerator I think should be 2J Omega because it you divide by Wn^2 it will be the result

[@JurnanSchilder]

No, it is correct. You divide not by omega_n^2 but by omega_n^4!