Number Of Shear Studs Research Articles

Five Machine Learning Models Predicting the Global Shear Capacity of Composite Cellular Beams with Hollow-Core Units

The global shear capacity of steel–concrete composite downstand cellular beams with precast hollow-core units is an important calculation as it affects the span-to-depth ratios and the amount of material used, hence affecting the embodied CO2 calculation when designers are producing floor grids. This paper presents a reliable tool that can be used by designers to alter and optimise grip options during the preliminary design stages, without the need to run onerous calculations. The global shear capacity prediction formula is developed using five machine learning models. First, a finite element model database is developed. The influence of the opening diameter, web opening spacing, tee-section height, concrete topping thickness, interaction degree, and the number of shear studs above the web opening are investigated. Reliability analysis is conducted to assess the design method and propose new partial safety factors. The Catboost regressor algorithm presented better accuracy compared to the other algorithms. An equation to predict the shear capacity of composite cellular beams with hollow-core units is proposed using gene expression programming. In general, the partial safety factor for resistance, according to the reliability analysis, varied between 1.25 and 1.26.

Numerical Investigation on the Pulling Resistant Capacity of Steel Beam-Concrete Wall Joints with T-stub Connectors

The steel frame-reinforced concrete core tube structural system is widely used in mid-rise and high-rise buildings due to its good seismic behaviour and high construction efficiency. Since the steel frame and the reinforced concrete core tube are supposed to deform synergistically under earthquake action, the steel beam-concrete wall joint (SBCW joint for short) will be subjected to a significant pull-out force. Therefore, the pulling resistant capacity of the SBCW joint is quite important for the seismic performance of the overall structure. In response to the shortages of the existing SBCW joint types, a new SBCW joint with a T-stub connector was proposed and studied. The experimental and analytical research has indicated that there are different failure modes and force mechanisms of the SBCW joint under pull-out load, and further studies are required for the pulling resistant capacity. On the basis of recent research findings, a numerical investigation on the pulling resistant capacity of the joint is conducted in this study. An elaborate 3D finite element model of the SBCW joint is proposed, and the load performance, strain and stress development, deformation characteristics and failure modes are analysed in detail. Then, a series of parametric analyses are carried out based on the finite element model, indicating that the length and the web height of the T-stub connector, the number of shear studs on the connector and the reinforcement ratio of stirrups have an obvious effect on the pulling resistant capacity. Finally, the critical value of the embedded depth of the connector, which is found to be one of the most important parameters for the failure mode and pulling resistant capacity of the joint, is determined, and design recommendations are proposed for the SBCW joints with T-stub connectors.

Stiffness analysis of shear stud group connectors in precast concrete deck

A refined finite element (FE) model was established to simulate the push-out test of shear stud group connectors (SSGCs). The failure phenomena and interface shear-slip curves obtained by the FE model were compared with the test results and found to be in good agreement. The verified FE model was then used in a parametric analysis, considering the concrete strength, stud diameter, stud height, stud spacings (longitudinal and transverse), strength of grouting material, and number of shear studs in a SSGC. Based on the Winkler foundation model and the comprehensive stiffness principle of thrust piles, a theoretical calculation formula for the stiffness of SSGCs was obtained, considering the concrete material, stud diameter, and number of shear studs in a SSGC. The calculation formula was verified with the test results and fitted with the FE analysis results.

Parametric Analysis of Structural Noise of Steel-Concrete Composite Slab Beams

In this study, the vibration acceleration and radiation structure noise in specific points, 30 cm away from the center surface of each plate of the concrete deck, web, and flange of the steel beam, are measured via the hammering test. The test is conducted on the middle concrete deck of an 8.5 m steel-concrete composite slab beam. The accuracy of the numerical model is then carefully justified. The influence of the number of shear studs, spacing, and arrangement of ribs on the concerning results is methodically examined and discussed by employing the numerical model. In the center frequency of 10–1000 Hz, the total sound power level of the structure can be lessened by improving the concrete deck thickness as well as the number of shear studs. The reduction of the rib spacing can effectively lessen the sound power level as well. The noise reduction of the plate with rib arrangement in the midspan zone is more influential than the case with uniform layout in the whole span.

Numerical investigation on progressive collapse resistance of steel-concrete composite floor systems

Steel-concrete composite floor systems are commonly used in steel buildings. Stability under gravity and lateral loading depends on these systems. To better understand the design parameters that govern the progressive collapse behaviour of steel-concrete composite floor systems, high-resolution finite-element analyses (FEA) is conducted. Steel fracture and concrete damage are explicitly considered in the finite-element model (FEM). The model is validated using full-scale test data including comparison of the measured response and failure modes. The validated model is used to conduct a parametric study to investigate untested parameters including (i) concrete strength, (ii) horizontal constraint, (iii) steel deck thickness, (iv) reinforcement ratio in the composite slab, and (v) the number of the shear studs. The simulation results are used to determine the optimum design to increase progressive collapse resistance. Specifically, it is found that increasing the continuity and the horizontal constraint of the steel deck, the steel deck thickness, and number of shear studs increase this resistance. Considering the steel consumption and the common practice in the construction, improving the continuity and the horizontal constraint of the steel deck are the best choices to improve the collapse resistance.

Structural Behavior of Composite Moment-Resisting Joints under Column-Removal Scenario

AbstractOne series of five composite joints with welded connections was tested and the influences of joint type, slab thickness, and number of shear studs were studied. Welded unreinforced flange w...

Hysteretic Assessment of Steel-Concrete Composite Shear Walls

This paper focuses on the hysteretic assessment of steel-concrete composite shear walls with reinforced concrete on one side of the steel plate. Finite element software ABAQUS is utilised to conduct this research. An experimental test on a composite shear wall is simulated to do the verification of the modelling. Then, modelling result is compared with the experimental test result which shows an insignificant difference between them and therefore uncovers the accuracy of the modelling. Thereafter, different parameters are considered to investigate their effects on the response of the walls. Thickness of reinforced concrete, steel plate thickness, and number of shear studs are studied as parameters. It is concluded that changing reinforced concrete thickness and number of shear studs do not considerably affect the ultimate load capacity, ductility, and energy dissipation of the walls. However, increasing the steel plate thickness enhances the ultimate load capacity, ductility, and energy dissipation. In addition, out-of-plane displacement of the walls is evaluated.

Composite joints with fin plate connections under a middle column removal scenario

Five simple beam-column joints with composite slabs were tested under a middle column removal scenario. Fin plate connection was used in all the joints. The influences of joint type, slab thickness, number of shear studs and bolt holes were investigated. Load-resisting mechanism of the composite joints against the applied ‘push-down’ load was investigated and the respective contribution of flexural action, compressive arch action and catenary action was quantified. Structural behaviour of the joints in terms of axial force, bending moment, failure mode and energy absorption was presented. To evaluate design values provided by current design guidelines and building codes, test results of the joints were compared with design values. It was found that the composite slab was beneficial to flexural resistance of the joints. Although tying capacity was reduced due to bending moment, tie force requirement could be met for conventional composite joints with 75 mm thick slab. A proposed novel fin plate connection with slotted bolt holes had better performance than conventional connection in terms of energy absorption and tying resistance. The test results provided a better quantitive understanding of FP connections under progressive collapse scenario and were able to serve as benchmark for further simplified numerical models.

Static Behavior of a Modified Through‐Core Connection between CFST Column and Composite Beam

Through‐core connection has been proven to be an ideal solution to ensure a rigid connection between steel beams and CFST columns. However, the traditional through‐core connection sometimes encounters concrete filling problems. A modified through‐core connection design with details of reduced flange width was therefore proposed. Through‐core reinforcements were added as supplements for tension load transfer. The monotonic loading tests and comprehensive FE simulations were performed to investigate the load bearing performance and working mechanism of this modified connection. The results indicated that the modified through‐core connection presented plasticity hinge failure at the beam end and crack formulation and progradation at the RC slab. The reduced flange width reduced the strength of the connection, but the reduction extent was limited. Due to the through‐core construction, the majority of internal forces at the beam were directly transferred into the column. The through‐core reinforcement can effectively participate in load bearing after the connection yields. The flange width reduction extent and the length of the reduction region must be controlled to ensure sufficient connection strength. The number of shear studs and TC reinforcements can influence the load bearing ability, and design suggestions are provided for the modified through‐core connection.

Shear behavior of short square tubed steel reinforced concrete columns with high-strength concrete

Six shear-critical square tubed steel reinforced concrete (TSRC) columns using the high-strength concrete (fcu,150 = 86.6 MPa) were tested under constant axial and lateral cyclic loads. The height-to-depth ratio of the short column specimens was specified as 2.6, and the axial load ratio and the number of shear studs on the steel shape were considered as two main parameters. The shear failure mode of short square TSRC columns was observed from the test. The steel tube with diagonal stiffener plates provided effective confinement to the concrete core, while welding shear studs on the steel section appeared not significantly enhancing the seismic behavior of short square TRSC columns. Specimens with higher axial load ratio showed higher lateral stiffness and shear strength but worse ductility. A modified ACI design method is proposed to calculate the nominal shear strength, which agrees well with the test database containing ten short square TSRC columns with shear failure mode from this study and other related literature.

Seismic behavior of shear-critical circular TSRC columns with a shear span-to-depth ratio of 1.3

Beam-column connections of steel reinforced concrete (SRC) structures are complicated and difficult to be constructed due to the densely arranged longitudinal reinforcements and stirrups. One good alternative is to use the composite construction where the reinforcing cage in the SRC column is replaced by an outer thin-walled steel tube, known as tubed steel reinforced concrete (TSRC). This paper presents and discusses the results of an experimental study on the seismic behavior of short circular TSRC columns with a shear span-to-depth ratio of 1.3. A total of 6 specimens using the high strength concrete with fcu,150 = 86.6 MPa were tested under simulated earthquake loading conditions, considering the two main parameters of axial load ratio and the number of shear studs on the steel shape. The short TSRC columns that failed in shear failure mode still showed good ductile behavior due to the effective confinement from the steel tube. Increasing the axial load ratio resulted in an increase of the lateral load resistance and energy dissipation capacity but decreased the ductility and deformation ability of the specimens. The shear studs welded on the steel shape had little effect on improving the seismic behavior of shear-critical circular TSRC columns. A modified ACI design method is proposed to predict the nominal shear strength of circular TSRC columns.

3D FE modeling considering shear connectors representation and number in CBGB

The use of composite structures is increasingly present in civil building works. Composite Box Girder Bridges (CBGB), particularly, are study of effect of shear connector's numbers and distribution on the behavior of CBGBs is submitted. A Predicti structures consisting of two materials, both connected by metal devices known as shear connectors. The main functions of these connectors are to allow for the joint behavior of the girder-deck, to restrict longitudinal slipping and uplifting at the element's interface and to take shear forces. This paper presents 3D numerical models of CBGBs to simulate their actual structural behavior, with emphasis on the girder-deck interface. Additionally, a Prediction of several FE models is assessed against the results acquired from a field test. A number of factors are considered, and confirmed through experiments, especially full shear connections, which are obviously essential in composite box girder. A good representation for shear connectors by suitable element type is considered. Numerical predictions of vertical displacements at critical sections fit fairly well with those evaluated experimentally. The agreement between the FE models and the experimental models show that the FE model can aid engineers in design practices of box girder bridges. Preliminary results indicate that number of shear studs can be significantly reduced to facilitate adoption of a new arrangement in modeling CBGBs with full composition. However, a further feasibility study to investigate the practical and economic aspects of such a remedy is recommended, and it may represent partial composition in such modeling.

Behaviour of both mechanically connected and bonded steel–concrete composite beams

This work analyses the behaviour of steel–concrete composite beams with shear connection realised by means of either the traditional welded-studs or an innovative bonded solution based. Experimental tests were carried out on fives composite beams. The distribution of interface shear stresses depends on several parameters, among which the distribution of shear force throughout the beam axis. The fully bonded connection ensures a continuous transmission of shear force between the steel beam and the concrete slab. The full connection between the concrete and the steel by shear studs is difficult to ensure. The connection quality between the two materials considerably depends on the number of shear studs. This assumption can only be accepted if concrete is not cracked. The variation of the neutral axis position depends on the applied load and the strain state of the steel beam. The strain distribution along the longitudinal and vertical directions is different in the bonded composite beam and the connected composite beam. The distribution of interface slips is also influenced by the solution adopted for shear connection. The experimental results are analysed and compared with those obtained by theory.

Discussion of "Strength Analysis of Steel-Concrete Composite Beams in Combined Bending and Shear"

In the paper, to assess the ultimate resistance of a simply supported composite beam, a three-dimensional beam element was used to model discrete stud shear connectors, and the studs were assumed to connect the middle plane of the concrete slab and the top steel flange of the steel beam both were modeled by shell element. This should be crucial in the finite-element study and raise a question how the shear connection stiffness in the analysis model was derived, which should not be the stiffness in real beam or that simply from push-out test. Accordingly, the full shear connection for a composite beam is known as being sufficient shear strength provided by the shear connectors in the critical shear span at the interface between the concrete slab and the steel beam to enable full plastic strength in the steel beam section. Let Pst be the design shear resistance of each stud; n be the available number of studs in the critical shear span; nf be the number of shear studs capable of being a full shear connection composite beam; and Fu be the ultimate longitudinal force resisted by the shear connectors. The required number of shear connectors within the critical shear span to enable full shear connection is determined as

Flexural Behavior of Composite Concrete Slabs Using Carbon Fiber Laminate Decks

In this research, the use of a carbon fiber epoxy deck to replace steel decks in composite concrete slabs was investigated. Deck thickness and presence or absence of steel bar reinforcement in the concrete topping were among test variables considered. The deck was premade, while the concrete topping was placed at a later stage. Four, 12.5-mm shear studs/each specimen were used to transfer forces among composite system components. Testing was in 4-point bending. Uneven distribution of load among shear studs due to the deck's nonductile behavior caused inner studs to fail prematurely in bearing resulting in a reduction of load-resisting capacity of composite samples. Based on test results, a larger number of shear studs were needed to reduce failure potential due to inadequate stress transfer, bearing failure at shear stud, and resultant deck buckling. Despite early letdown of brittle carbon fiber decks, concrete toppings with added steel bars maintained their bending resistance due to enhanced ductility and toughness.

Composite Beams Subjected to Static and Fatigue Loads

This paper presents experimental results of 44 composite beam structures tested under static and fatigue loads. While designing the specimens, variables considered included: (1) the number of shear studs; (2) reinforcing method (deformed bars versus welded wire fabric); and (3) load levels and load ranges for fatigue tests. Results show that (1) cracks were initiated in the concrete slab; (2) propagation and connection of cracks led all specimens to fail; (3) the shear studs become stressed after formation of the cracks; (4) crushing of concrete near the shear studs was observed in some fatigue tests; and (5) the flexural stiffness of the specimens decreased through fatigue tests. The specimens containing wire mesh are superior to those containing steel bars. Moreover, no practical difference in structural behavior was found between the full composite and the 80% composite specimens.

Tracing Initiation and Propagation of Cracks in Composite Slabs

This paper presents test results obtained from studies aimed at determining whether the impact-echo method, a nondestructive test technique based on the use of transient stress waves, can be used to trace the initiation and propagation of cracks in composite slabs subjected to static loads. The number of shear studs in the specimens was designed to satisfy the requirement of the American Institute of Steel Construction Allowable Stress Design (ASD) specifications for full-composite and 80 partial-composite structures. To trace the initiation and propagation of cracks in the specimens, impact-echo tests were carried out at steps with different load levels. Throughout the test, the strains of shear studs were also measured to verify the results obtained from the impact-echo tests. It is shown that changes in the impact-echo responses are the key to detecting the formation of a crack in the composite slabs. The location of the crack can be determined by the impact-echo method. Results also show that the stra...