Numerical assessment of slab-interaction effects on the behaviour of steel-concrete composite joints

Abstract

In current design practice for seismic resistant steel braced frames, general rules and standard provisions are\ud aimed to ensure a structural behaviour for beam-to-column joints of non-braced spans as close as possible to\ud perfect hinges. This is done to prevent any kind of interaction with the bracing systems, in particular under\ud horizontal loads. However, the global performance of composite joints is markedly affected by the structural\ud interaction between the concrete slab and the steel components and - especially during seismic events - struts\ud can occur in the slab at the beam-to-column intersection.\ud In this paper, the possibility of realizing a composite joint that behaves as moment-resisting under gravitational\ud loads and essentially as hinged under horizontal loads is investigated. Aiming to assess the actual slab-interaction\ud effects on the overall response, a full 3D Finite Element (FE) model representative of a beam-to-column composite\ud joint taking part of a braced frame is described in ABAQUS and validated towards past full-scale experiments.\ud A parametric study is hence proposed, by accounting for three geometrical configurations, being characterized by\ud (i) isolated slab with absence of rebar continuity (i.e. fully disconnected slab and steel joint only), (ii) presence of\ud slab with partial column interaction (i.e. isolated slab and continuity of rebar), (iii) presence of fully interacting\ud slab. It is shown that, if properly detailed, a joint with isolated slab and continuous rebars can be used in nonbraced\ud spans of composite braced frames without affecting the behaviour of the bracing system (i.e. as in\ud presence of a hinge). Nonetheless, the composite beam can be designed as continuous on multiple supports\ud under vertical loads, hence leading to a reduction of the steel cross-sectional size

Research on Application of Uplift-Restricted Slip-Permitted (URSP) Connectors in Steel-Concrete Composite Frames

“…Among them, the steel-concrete composite frame is currently a widespread structural system in multistory and high-rise buildings since it combines the advantages of both steel and concrete frames, thus leading to, in many cases, a reduction of costs and optimization of the structural performance [16,17]. The mechanical behavior of composite frame systems including experimental and theoretical research, has been reported in detail over the last few decades [18][19][20][21], and previous research, has demonstrated that the presence of reinforced concrete (RC) slabs is beneficial to the flexural capacity, stiffness and lateral stability of steel beams, which also improves the seismic performance of the frame [22,23].…”

“…Sci. 2019, 9, x FOR PEER REVIEW 2 of 24 stiffness and lateral stability of steel beams, which also improves the seismic performance of the frame [22,23]. However, under vertical and seismic loads, tensile stresses and cracks may occur in the concrete slab at beam ends where a hogging moment exists, which has always been a critical issue hindering the widespread application of steel-concrete composite structures.…”

Numerical Study on the Seismic Performance of a Steel–Concrete Hybrid Supporting Structure in Thermal Power Plants

“…It is known that the numerical simulation is another effective approach to investigate the seismic performance of structures, and significant progress has been made in the development of nonlinear analysis programs for evaluating the seismic performance of steel-concrete hybrid structures [17][18][19][20][21]. Accordingly, on the basis of experimental results, the numerical investigation on the seismic performance of this hybrid structure was conducted in this study.…”

Structural Behavior of Steel-Concrete Composite Beam using Bolted Shear Connectors: A Review

“…Shear connection ratio of a composite beam depends on the number of connectors in the beam. A full shear connection in steel-concrete composite beam is recommended by most of the researches as it will gives higher ultimate strengths than partial shear connection [31][32][33][34][35][36]. This also proved by Kwon et al that the strength, stiffness, and deformation capacity of the composite beams increased with increasing shear-connection ratio [29].…”