Two nonlinear beams with definitions of ductility

TWO MATHEMATICAL MODELS OF NONLINEAR BEAMS WHICH CAN BE USED TO REPRESENT THE GIRDERS AND COLUMNS OF A NONLINEAR MULTISTORY STRUCTURE ARE DESCRIBED AND COMPARED. ONE BEAM MODEL IS LIMITED TO BILINEAR BENDING MOMENT-END ROTATION HYSTERETIC CHARACTERISTICS. THE OTHER MODEL CAN HAVE DIFFERENT CURVILINEAR AND BILINEAR HYSTERETIC CHARACTERISTICS AT EACH END. THREE DIFINITIONS OF DUCTILITY FACTOR ARE MADE AND APPLIED TO YIELDING BEAMS. THESE TYPE OF BEAM MODELS CAN BE USED IN THE STUDIES OF THE DYNAMIC RESPONSE OF EARTHQUAKE EXCITED MULTI-DEGREE OF FREEDON YIELDING STRUCTURES. /ASCE/