Power Flow and Energy Sharing in Random Vibration

The time‐average power flow between two linearly coupled oscillators excited by independent white‐noise sources is shown to be proportional to the difference in the time‐average energies of the oscillators. This proportionality is independent of the strength of the coupling if the oscillator energies are correctly defined. Power balance and energy sharing in the two oscillator systems are investigated, and the power‐flow energy‐difference proportionality relation is extended to a group of N linear oscillators, all with the same natural frequencies and damping ratios and each coupled to all the others by identical springs and masses. The coupled‐oscillator results are applied to a simple coupled‐beam example, in which two almost identical Bernoulli‐Euler Beams are lightly coupled together by stiffness terms. Experimental measurements for this system provide verification of the power‐flow equations provided that the coupling loss factor be correctly computed.