Rocking of Rigid Block Under Minute Fluctuation of System/Excitation Parameter (2nd Report, Minute Fluctuation of Restitution Coefficient)

Abstract

This investigation deals with the rocking response of a rigid block subjected to 1-dimensional harmonic excitations with minute changes of the system parameter, namely, the restitution coefficient, and excitation parameters, such as frequency, amplitude and phase. This paper is the part two of the examination about the effects by those minute changes and is related with the minute change of the restitution coefficient. The numerical analysis is carried out by solving the nonlinear equations of motion governing the rocking motion of a rigid block subjected to the horizontal base harmonic excitation. Natural changes of not only the restitution coefficient but also the excitation are realized by the random numbers with normal probability distribution. The analytical results showed that the rocking responses are very sensitive to small changes of the restitution coefficient and the base excitation, and their effect is also large. Minute change of the restitution coefficient or the excitation phase makes the rocking response unstable and the distribution shape of rocking response change massively.