Analysis and design of a quick engage clutch for seismic applications.

摘要

Seismic isolation is an important technology used in earthquake engineering. To date, significant research has been carried out in this field to continuously improve the effectiveness and safety of seismic isolation. Generally speaking, isolation bearings are used to reduce the absolute acceleration of superstructures. However, such a device may introduce certain drawbacks due to large bearing displacement, which hinders the best performance. Using large damping is one effective way to regulate the bearing displacement. The corresponding dampers, on the other hand, can increase the base shear due to bridge thermal extensions. In addition, frequent thermal excursions can wear out the damper quickly.;The main objective of this thesis is to design a mechanical device, namely a Quick Engage Clutch, which can act together with seismic isolation dampers and has the capability of controlling the seismic vibrations. This device under normal conditions will not be engaged so that dampers will not be connected, thus allowing free bearing displacement due to thermal extensions. However, under strong ground excitation, the device can be quickly engaged so that dampers can be rapidly connected to regulate the displacement.