Sequential Coupling: New Structural Connection for Seismic Control

A new method of connecting members, at certain joints of a lateral force resisting structure, improves the response to seismic excitation. These connections that permit a small initial slip (displacement or rotation) are called sequential connectors. A sequential system is a structure consisting of units coupled in parallel in which at least one unit is attached by sequential connectors, and at least one other unit is attached by standard connections. A standard structure is transformed into a sequential system by replacing one or more (but not all) standard connections by sequential connectors. The effectiveness of sequential coupling, in some cases, is comparable to sensor‐initiated active controls. Sequential systems exhibit an interesting and even surprising response to dynamic excitation. The paper outlines the characteristics of sequential systems and provides a numerical comparison of their performance with an identical structure using standard connections; the structure using standard connections shows a displacement response that is 40% higher. If the response of the two systems is identical, the standard system requires 40% more material.