Monotonic Behavior of a Novel Energy Dissipative Mechanical Connector

Abstract

Prefabrication technology has gained an increasing demand during the past decades due to some crucial benefits such as; ensuring material and labor quality and quick assembling features. Past earthquakes have shown that beam to column connections of precast structures demonstrated inadequate seismic performance. Lack of robust connections, inadequate detailing of ductile elements and displacement incompatibility of structural and non-structural elements led to nonuniform distribution of lateral loads among the structural system. Thus, special attention should be paid to the design and construction of beam to column joints. Several proposals exist for the joints in the Turkish Building Earthquake Code2018 (TBEC-2018), which are categorized as moment resisting and non-moment resisting connection details. However, all these proposed connection details need concrete pouring and steel welding on-site requiring careful inspection during construction. In this study, fuse type mechanical couplers (MCs) are proposed, as a robust dry connection tool for use in beam to column connections of precast structures. The main philosophy of the connection aims to decouple the moment effects to two axial forces in opposite directions acting on MCs, where the shear force is transferred by a steel hinge, which is located at the natural axis of the beam. Since the fuse elements are strut type slender elements, they have serious vulnerability in terms of buckling. The preliminary development process for the MCs with improved buckling behavior is demonstrated herein. Preliminary monotonic experiments performed on MCs showed that the preliminary design could contribute to energy dissipation by yielding of fuse elements. The buckling behavior could be improved by the use of external steel jackets.