STUDY OF THE BEHAVIOR AND DUCTILITY OF MOMENT CONNECTIONS WITH TAPERED BEAMS USING THE YIELD LINES THEORY

Ductility is proposed as one of the primary concepts for the structures' plastic and seismic design. Ductility is generally measured in designing with the member's capacity of rotation. In case of a correct designing of the connections and supply of seismic compression to a cross-section of the beam's web and flange, the failures will stem from the occurrence of in- or out-plane plastic buckling. The present study calculates the rotation capacity of the beam-to-column momentonnections with tapered beams compressible seismic cross-sections in the web through the use of yield lines theory and the principles of analyzing rigid plasticity originating from the cyclic loading and potential energy minimization. Then, the ductility obtained from the method described above will be compared with the numerical calculations resulting from the finite element analysis. In the end, a laboratory sample will be made for comparing the occurred failure mechanism with the mechanisms obtained from plasticity analysis. The obtained results are indicative of the appropriate match between the ductility rates calculated through the three aforementioned methods as well as meeting of the guidelines' requirements for the use of the aforesaid connections in special moment frames.