Bending and rotational behaviour of semi-continuous composite beams

Design of simply-supported and continuous beams in steel-concrete composite construction

Differences in inelastic properties of steel and composite beams

Behaviour and design of composite beams subjected to sagging bending and axial compression

In a steel-concrete composite beam (hereafter referred to as a composite beam), partial interaction between the concrete slab and the steel beam results in an appreciable increase in the beam deflections relative to full interaction behavior. Moreover, the distribution type of the shear connectors has a great impact on the degree of the composite action between the two components of the beam. To reveal the effect of shear connector layout in the performance of composite beams, on the basis of a developed one-dimensional composite beam element validated by the closed-form precision solutions and experimental results, this paper optimizes the layout of shear connectors in composite beams with partial interaction by adopting a stepwise uniform distribution of shear connectors to approximate the triangular distribution of the shear connector density without increasing the total number of shear connectors. Based on a comparison of all the different types of stepped rectangles distribution, this paper finally suggests the 3-stepped rectangles distribution of shear connectors as a reasonable and applicable optimal method.

In this paper, a simplified approach based on critical temperature for fire resistance design of steel-concrete composite beams is proposed. The method for determining the critical temperature and fire protection of the composite beams is developed on the basis of load-bearing limit state method employed in current Chinese Technical Code for Fire safety of Steel Structure in Buildings. Parameters affecting the critical temperature of the composite beams are analysed. The results show that at a definite load level, section shape of steel beams, material properties, effective width of concrete slab and concrete property model have little influence on the critical temperature of composite beams. However, the fire duration and depth of concrete slab have significant influence on the critical temperature. The critical temperatures for commonly used composite beams, at various depth of concrete and fire duration, are given to provide a reference for engineers. The validity of the practical approach for predicting the critical temperature of the composite beams is conducted by comparing the prediction of a composite beam with the results from some fire design codes and full scale fire resistance tests on the composite beam.

Experiment and numerical simulation on bearing capacity of partial steel-ultra-high-performance concrete continuous composite beams

Experimental investigation on flexural performance of steel-UHPC composite beams with steel shear keys

Three-Dimensional FE Modelling of Simply-Supported and Continuous Composite Steel-Concrete Beams

Experimental, analytical, and numerical investigation on flexural behavior of the gradient UHPC-NC composite beams

The behaviour of composite steel-concrete beams subjected to pure flexure and the presence of flexure and shear is fairly well understood and provisions do exist in international codes of practice for their design, however in most instances the influence of the concrete slab is not included in the strength design of the composite beam in shear. Combined internal actions including the presence of torsion and flexure have also been considered of late. These actions combine to occur in edge beams and curved composite beams and thus are of significant practical interest. Of increasing interest has become the presence of axial force and flexure in composite beams. These internal actions need to be considered in the design of raking beams of stadia, elevated approach spans for bridges and interchanges and in the design of integral abutment bridges and cable stayed bridges. Furthermore, composite beams in floor systems for braced multi-storey buildings are often required to resist axial force, flexure and shear force. This paper considers the effects of the presence of axial force in conventional composite beams. The effects of different forms of axial force and flexure combinations are considered in this paper. An analytical treatment, experiments and design approaches are given in this paper which is useful for structural engineers. Furthermore research in this area is also discussed. This paper will also present the results of an extensive experimental series to study the behaviour of high performance steel sections subjected to transverse impact loads which are able to simulate either a collision or blast. The experimental program has considered both mild structural steel and stainless steel hollow sections both filled and unfilled being tested. The purpose of the tests was to identify the potential advantages of using concrete infill to increase the energy absorption capability of steel hollow sections.

Experimental research on the structural performance of continuous composite beams with uplift-restricted and slip-permitted connectors

This study investigates the stability and vibration characteristics of variable stiffness laminated composite (VSLC) beams subjected to thermo-mechanical loadings. A semi-analytical model is developed to determine the buckling and vibration characteristics of variable stiffness composite beams. The model employs a displacement-based Ritz approach to derive the matrix representation of the governing equations. Modified constitutive relations are derived to account for the Poisson effects that arise due to the development of zero-stress conditions in the width direction of beams. The material properties and temperature variations are assumed to be constant across the thickness of the beam. Moreover, finite element calculations are carried out using commercial software ABAQUS in conjunction with a MATLAB-generated input file, which is utilized to capture fiber angle variations within the beam. Numerical results are obtained to elucidate the effect of slenderness ratio, modulus of elasticity ratio, boundary conditions, number of layers, and ply-sequence on the free vibration and instability characteristics of VSLC beams subjected to mechanical loadings and thermal environments. This study underscores the crucial importance of taking these factors into account for precise and dependable design and analysis of such composite beams in engineering applications.

This study intends to improve the efficiency of the composite beam combining a slab made of steel fiber‐reinforced ultrahigh performance concrete (UHPC) and a steel girder without top flange. To that goal, the experiment is conducted on 24 composite beams fabricated with varying compressive strength of UHPC, steel fiber content, stud spacing, and slab thickness to evaluate the behavior of the studs and the flexural behavior of the composite beam combining the UHPC slab and the inverted‐T steel girder. The experimental results show the test members developed sufficient ductile behavior with respect to the slip limit of 6 mm stipulated in Eurocode‐4 and regardless of the considered test variables. The experimental ultimate horizontal shear force is seen to be clearly larger than the static strengths of the stud predicted by Eurocode‐4 and AASHTO‐LRFD. Improved design formulae for the composite beam shall be derived to reflect the UHPC slab thickness.

Time-dependent analysis of composite beams with continuous shear connection based on a space-exact stiffness matrix

Adopting hybrid cellular I-sections can favor optimizing steel consumption, as the higher steel grade is localized only in the compression tee. In addition, continuous steel-concrete composite cellular beams allow the construction of longer spans due to the combination of higher bending stiffness of the cellular I-section and its connection with the concrete slab, further the continuous of the beam, which provides a better distribution of the bending moment diagram. However, due to the hogging moment on the support regions, the steel-concrete composite beam can present lateral instability of the compression flange accompanied by web distortion, named Lateral-DistortionalBuckling (LDB). No investigations have evaluated the behavior of steel-concrete composite beams with hybrid cellular I-section under hogging moment. This way, the present study aims to assess the behavior of the structure in question using a nonlinear finite element model via ABAQUS software. The investigation consists of verifying the beams' failure mode, considering plastic behavior or LDB, and the effectsof different combinations of steel grades for the hybrid I-section, and further comparing the use of hybrid and homogeneous steel profiles on the composite beams.