Connections in mixed structures with steel columns with threaded rods and normal strength concrete beams: Numerical analysis with incremental load

Abstract

ABSTRACTThis research proposes to evaluate the suitability of a new type of hybrid or mixed joint for framed structures that are composed of H shape vertical elements made of structural steel and reinforced concrete with rectangular section horizontal elements. Researchers of Spanish origin have made the first experimental campaigns of these mixed joints using stud connectors welded to the flanges of the structural steel, which implies a follow‐up to the welding procedure. These researchers have concluded that these joints offer good resistance to static loading and that the contribution of strength by adherence and friction between the steel column and the concrete beam is important. In the framework of this research, relevant laboratory tests (cyclic load tests) will be carried out to evaluate and characterize the behavior of the joint in the event of seismic events, for areas of high seismic hazard, in addition, the modeling of the joint using the Finite Elements Method and the theory of mixtures of composite materials that anticipates their mechanism of failure. The innovative components of this research are the implementation of threaded rods, which will cross the flanges of the steel column and the evaluation of this joint under cyclic loading. This article will present and analyze the results of the first stage of this investigation, in which two partial models of the mixed joint with static load were made, which was applied at the end of each of the beams until producing its mechanism of failure. The results show an early failure mechanism on the outside contact surface between the two materials and deformations in the column outside the area embedded by the concrete.