On the response of eccentric non-structures subjected to horizontal oscillation

In contrast to building structures, little attention has been paid to the seismic performance of non-structures in buildings, especially of eccentric non-structures. This paper attempts to explore the rocking and overturning of eccentric blocks, which could be the equipment or non-structural components in buildings, subjected to horizontal vibration. In the present study, a non-structure is regarded as a rigid block with tunable mass eccentricity, and the contact friction is assumed to be large enough to prevent the rigid block from sliding. A free shaking test is first carried out to determine the value of the coefficient of restitution. Force oscillations are then investigated to determine the critical time and acceleration when the eccentric blocks fall down under the swept-frequency oscillation. Finally, an actual acceleration from the seismic records is executed on each of the eccentric blocks to measure and to explore the corresponding toppling probability. It is found that the toppling of blocks is not necessarily linked to the magnitude of the peak ground acceleration.