SEQUENTIAL CONNECTOR: A NEW STRUCTURAL CONNECTION FOR EARTHQUAKE RESISTANT STEEL STRUCTURES

THERE EXIST NUMEROUS DEVICES THAT IMPROVE THE PERFORMANCE OR REDUCE THE COST OF EARTHQUAKE RESISTANT STRUCTURES. THESE DEVICES, SUCH AS DAMPERS, ISOLATORS, ENERGY DISSIPATORS, AND ACTIVE CONTROLS, USE MATERIALS AND TECHNOLOGY THAT ARE QUITE NEW AND UNTRIED. THEIR LONG-TERM ENDURANCE, MAINTENANCE REQUIREMENTS, AND PRACTICAL APPLICABILITY HAVE YET TO BE DEMONSTRATED. RESEARCHERS ARE DEVELOPING A DEVICE THAT IS COMPLETELY WITHIN THE STATE-OF-THE-ART OF STANDARD STRUCTURAL STEEL CONSTRUCTION. IT CONSISTS OF A SPECIALIZED CONNECTOR CALLED THE "SEQUENTIAL CONNECTOR" THAT ADMIST AN INITIAL, LIMITED, AND REPEATED ZERO RESISTANCE SLIP UNDER LOADING. THIS CONNECTOR IS USED FOR SOME OF THE CONNECTIONS IN A STANDARD STRUCTURE. A STRUCTURAL ELEMENT, CONNECTED BY MEANS OF THE SEQUENTIAL CONNECTOR TO A LATERAL FORCE RESISTING SYSTEM, AUGMENTS THE RESISTANCE OF THE SYSTEM WITHOUT A CORRESPONDING INCREASE IN ITS RESPONSE FREQUENCY. THIS UNIQUE PROPERTY PRODUCES A RESPONSE TO SEISMIC EXCITATION THAT IS SIGNIFICANTLY LOWER THAN THE DISPLACEMENT RESPONSE IF A STANDARD CONNECTION IS USED. THE DEVELOPMENT AND APPLICATION OF THIS INNOVATION WILL SIGNIFICANTLY REDUCE THE COST OF EARTHQUAKE MITIGATION AND IMPROVE THE PERFORMANCE OF STEEL BUILDINGS.