The description and measurement of nonlinear damping in structures

This paper addresses the question of a description of the damping characteristics inherent in real structures. A discussion of the mechanisms causing energy loss and the practicalities of measurement when the parameter is not only nonlinear but also the forcing function and the response are nonstationary is followed by some practical results obtained from very tall buildings. The random decrement signature is presented as being particularly useful for the measurement of damping characteristics under hostile loading regimes, and its use is demonstrated and described.