Here, we consider the iconic model of Fig. 5.26 that represents an aircraft engine undergoing tests on an elastic foundation. Find the amplitudes of the oscillations exhibited by each end of the pad when the engine exerts a moment τ (t) = τ₀ cosωf t on the pad, where ω_f = (3/2) √k/m. 

To do this, note that the mathematical model of the system can be cast in the form

It will be helpful to recall the steady-state time response of a single-dof undamped system to the function A cos(ω_ft), as derived in Sect. 2.7.3, which is reproduced below in a form suitable for the problem at hand:

Transcribed Image Text:

F x1 S wwww I 19 Fig. 5.26 A test pad mounted on an elastic suspension m, l Te www x2