ACTIVE CONTROL FO BUILDING STRUCTURES USING SHAPE-MEMORY ALLOYS

SEVERAL PROPERTIES DISPLAYED BY MEMBERS OF THE SHAPE-MEMORY FAMILY OF ALLOYS, INCLUDING: (1) SHAPE-MEMORY BASED ON A TEMPERATURE INDUCED PHASE TRANSFORMATION; (2) PSEUDOELASTICITY BASED ON A STRESS INDUCED PHASE TRANSFORMATION (3) EXCELLENT FATIGUE AND CORROSION RESISTANCE, CAN BE EXPLOITED INDIVIDUALLY AND IN COMBINATION TO PROVIDE BOTH ACTIVE AND PASSIVE ASEISMIC CONTROL FOR ALL SORTS OF STRUCTURES. ACTIVE, PASSIVE, OR COMBINED ACTIVE/PASSIVE DEVICES CAN CONTROL BOTH STRUCTURAL STIFFNESS AND DAMPING IN OPEN LOOP OR CLOSED LOOP CONTROL SCHEMES. DEVICE TYPES INCLUDE LINKAGE DEVICES, MODIFIED JOINT DEVICES, MODIFIED MEMBER DEVICES. THIS STUDY WILL DEVELOP THIS PROMISING ASEISMIC TECHNOLOGY BY PROVIDING: (1) MATERIALS CHARACTERIZATION FOR ALL RELEVANT ALLOYS INCLUDING SHAPE-MEMORY, PSEUDOELASTICITY, AND FATIGUE BEHAVIOR, THERMOMECHANICAL PROCESSING, ECT. (2) ACTUATOR CHARACTERIZATION FOR ALL DEVICE TYOPES INCLUDING ACTUATOR FORCE, ACTUATING MECHANISM, CONTROL CHARACTERISTICS INCLUDING DYNAMIC RESPONSE, RELIABILITY, COST, AND EXPECTED LIFE. (3) A DEMONSTRATION OF THE MOST PROMISING DEVICE FOR A FRAMED STRUCTURE ON A SMALL SCALE SHAKE-TABLE FACILITY.