scholarly journals Optimal Design of Steel–Concrete Composite Beams Strengthened under Load

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4715
Author(s):  
Piotr Szewczyk ◽  
Maciej Szumigała

This paper presents results of numerical analysis and experimental research on strengthening of steel–concrete composite beams. Studied members consisted of IPE200 I-beam and 90 × 700 mm reinforced concrete slab. The steel part of the section was strengthened by welding additional steel plates at the bottom. The study was performed for plate thickness ranging between 6 to 22 mm. Spatial FEM models were developed to account for material and geometric nonlinearities and for stress and post-welding strain. Proposed numerical models were experimentally validated. One aim was to find an optimum solution which would minimize cost and maximize bending capacity. To achieve this, energy parameters available in numerical simulations were reviewed and analyzed. Recoverable strain energy value determined in Abaqus was used to find the optimum solution.

2020 ◽  
Vol 23 (10) ◽  
pp. 2220-2236
Author(s):  
Haolei Wang ◽  
Tao Sun ◽  
Chen Tang ◽  
Jiejun Wang

This article proposes a new kind of continuous composite beam that consists of steel box-girder and ultra-high-performance concrete waffle slab. The ultra-high-performance concrete helps increase the ultimate capacity and span of structure while reducing the risk of cracking that occurs with ordinary concrete. In order to investigate the mechanical properties of this new type of composite structure, two scaled specimens were designed and tested. One was a steel–ultra-high-performance concrete continuous composite beam, whereas the other, as a control specimen, was a prestressed steel-concrete continuous composite beam. The test results indicate that the bending capacity of steel–ultra-high-performance concrete continuous composite beam is 1.2 times that of steel-concrete continuous composite beam; the cracking strength of steel–ultra-high-performance concrete continuous composite beam is larger than 20 MPa, much higher than the conventional one; the crack development pattern of steel–ultra-high-performance concrete continuous composite beam has its own characteristics, and the cracks appeared in ultra-high-performance concrete slab dominated by micro-cracks with smaller length are numerous and intensive. A finite element model was developed to predict the behavior of steel–ultra-high-performance concrete continuous composite beam. Comparing the numerical and experimental results indicates that, generally, the numerical model can simulate the structural behavior of steel–ultra-high-performance concrete continuous composite beam reasonably. Based on the numerical model, a series of parameter analyses were performed, which indicate that the strength grade of steel, web, and bottom plate thickness play an important role in improving the bending capacity of steel–ultra-high-performance concrete continuous composite beam; the axial tensile strength of ultra-high-performance concrete, rib, and top plate height of ultra-high-performance concrete slab can enhance the bending capacity to a certain extent.


2018 ◽  
Vol 7 (3.10) ◽  
pp. 54
Author(s):  
T Subramani ◽  
A Periasamy

Composite plays a vital role in replacing the existing mild steel in reinforcement and exterior truss structure. This study proposed to design shear connector for joining concrete slab and steel section. Shear connectors has analyzed and predict the best connector for a particular composite beam with respect to static load and the amount of steel in the connector as a common aspect. The use of composite structures is increasingly present in civil construction works nowadays. Composite beams, especially, are structures which include substances, a metal phase placed in particular inside the tension region and a concrete phase, positioned in the compression go sectional location, both are related with the aid of steel gadgets called shear connectors. The main features of this connector are to permit the weight for the joint the beam-column, to restriction longitudinal slipping and uplifting on the factors interface the shear forces. Our project paper presents 3D numerical models of steel-concrete composite beams to simulate their structural behaviour, with emphasis on the beam column interface using Simulations software ANSYS 18.1 based on the Finite Element Method. Mostly these type of structures are widely used in the dynamic loading structures like bridges and high rise buildings.  


2003 ◽  
Vol 9 (5) ◽  
pp. 529-565 ◽  
Author(s):  
Michele Dilena ◽  
Antonino Morassi

This paper is the second part of an experimental-analytical investigation on the dynamic behavior of damaged steel-concrete composite beams. In the first part of the research, we presented and discussed the experimental results of a comprehensive series of dynamic tests performed on composite beams with damage in the connection. Experimental observations suggested the formulation of a composite beam analytical model, where the strain energy density of the connection also includes an energy term associated to the occurrence of relative transversal displacements between the reinforced concrete slab and the steel beam. A comparison with experimental results shows that the model enhances accuracy in describing the undamaged state of composite beams and that it is also appropriate to accurately predict the dynamic behavior under damaged conditions. A damage detection technique based on the measurement of variation in the first flexural frequencies was then applied to the suggested model and gave positive results.


2018 ◽  
Vol 61 (2) ◽  
pp. 509-521 ◽  
Author(s):  
Allan A. Andales ◽  
Dale Straw ◽  
Thomas H. Marek ◽  
Lane H. Simmons ◽  
Michael E. Bartolo ◽  
...  

Abstract. Accurate estimates of crop evapotranspiration (ET) are needed to effectively manage irrigation resources in the Arkansas River basin in Colorado and to maintain compliance with the Arkansas River compact with Kansas. This was a major impetus for the construction of a precision weighing lysimeter in the Arkansas River basin at the Colorado State University (CSU) Arkansas Valley Research Center (AVRC) near Rocky Ford, Colorado. The objective of this article is to describe the design and construction of the weighing lysimeter and characterize its performance and unique features. The main components of the lysimeter facility are the foundation, the scale system, the soil monolith tank, and the outer tank that houses the aforementioned components. The foundation, which was 4.12 m below the ground surface, consisted of a reinforced concrete slab 2.00 m wide by 6.31 m long and 0.20 m thick that was anchored to six square shaft helical anchors. The outer tank was secured onto the foundation and had a rectangular floor area of 6.10 m × 1.79 m (10.92 m2), an interior vertical clearance of 2.15 m, and walls made of reinforced 8 mm thick steel plates. The floor scale system (mechanical levers and load cell) was installed inside the outer tank and had a gross capacity of 17 Mg. The monolith tank (1.50 m × 1.50 m area, 2.44 m depth, 10 mm steel walls) containing an undisturbed soil profile was set on the scale system. The lysimeter facility was installed in the middle of a 3.5 ha field. Calibration of the scale system resulted in a linear response (R2 = 1.000), with an equivalent conversion coefficient (slope) of 151.09 mm H2O (mV V-1)-1. The sensitivity of the scale system was 0.023 mm of water, which is sufficient for measuring diurnal (15 min to hourly) changes in ET and soil water. Load cell readings taken at a frequency of 0.5 Hz were averaged in 15 min intervals (450 readings per 15 min) to filter out the measurement noise that was attributed to wind. The lysimeter was found to adequately detect ET, irrigation, and precipitation perturbations with an actively growing alfalfa hay crop ( L.) in 2011. The lysimeter facility is a state-of-the-art tool for quantifying ET of irrigated crops in the lower Arkansas basin in southeast Colorado. Keywords: Calibration, Evapotranspiration, Load cell, Weighing lysimeter.


2019 ◽  
Vol 12 (3) ◽  
pp. 509-517
Author(s):  
O. P. AGUIAR ◽  
R. B. CALDAS ◽  
F. C. RODRIGUES ◽  
H. N .BELLEI

Abstract In search of an improved compatibility between cold-formed steel profiles and precast floor systems, this study proposes an alternative shear connector for cold-formed steel-concrete composite beams. This connector consists of a steel plate with holes placed longitudinally in the middle of the upper flange of the steel profile, aiming to maximize the support area for precast slabs during the assembly. The proposed solution was experimentally tested on I-beams under bending, composed by two cold-formed steel channels, connected to a reinforced concrete slab by the shear connector. The relative slip between the steel profile and concrete, vertical deflection of the beam, and strains at several locations of the composite section were measured. The results show that the proposed connector assures shear transfer at the interface of the composite section components and shows strength of the same magnitude as other commonly used connectors.


2008 ◽  
Vol 136 ◽  
pp. 145-152 ◽  
Author(s):  
Bryan Lim ◽  
Pei Jun Hong

Concrete when subjected to a blast loading from a close-in detonation will experience spalling due to formation of tension waves on the opposite face of the concrete panel. The spalled concrete may be ejected at high velocity causing undesirable effects to occupants. Tests using 1/2kg TNT blocks were conducted on 100mm thick concrete panels to study the effects of spalling and whether the spalled materials can be arrested using a sprayed-on polymeric coating. From the tests, it was observed that without the sprayed-on polymeric coating, extensive spalling occurred. However, with just a 3-4mm thick layer of sprayed-on polymer, the spalled materials were arrested and contained. Numerical models of the reinforced concrete slab were created using Autodyn 2D and the results of the simulation were compared to observations from the tests. There was good correlation between the test results and the simulation results as the size of the crater, both front and back, on the concrete slab were rather similar.


2021 ◽  
pp. 204141962110489
Author(s):  
Hani Mahdavi Talaromi ◽  
Farhad Sakhaee

Numerical models have been used recently to analyze concrete structures subjected to high-impulsive loads. A material model that can well capture the mechanical behaviors is crucial to obtain reliable results. Present study, focused on reinforced concrete slab as a major load carrying element of the RC structures under blast loading. By performing several simulations in popular and powerful concrete constitutive models, including concrete damage R3, HJC, CSCM, and Winfrith the accuracy of these models was investigated. Maximum deflections have been compared with each other and expanded further to compare with experiments. Result showed all models have an acceptable accuracy in estimating maximum slab deflection. Concrete Damage R3 presented the highest accuracy. HJC has the second rank and CSCM and Winfrith have the third and the fourth places, respectively. HJC needed the minimum computation time. CSCM had minimum input parameters but includes maximum calculation time. Winfrith had the lowest accuracy, however this model presented very conservative results. Uniaxial compressive and tensile stress-strain curves showed that the models which presented higher values of strength, evaluated lower maximum values of deflection.


2019 ◽  
Vol 19 (07) ◽  
pp. 1950079 ◽  
Author(s):  
João Victor Fragoso Dias ◽  
Janaina Pena Soares Oliveira ◽  
Adenilcia Fernanda Grobério Calenzani ◽  
Ricardo Hallal Fakury

Great attention has been given in the last few years to steel–concrete composite beams due to the gains in strength that can be obtained with the small cost of installing a shear connection between the steel profile and the concrete slab. In continuous and semicontinuous composite beams close to the internal supports, hogging bending moments are developed and the compressed bottom flange may buckle laterally in an unstable way known as the lateral-distortional buckling, characterized by a horizontal displacement and twist of the bottom flange with an out-of-plane distortion of the web. In the literature, several formulations were proposed to determine the critical moment for this type of buckling. Among them, some of the most relevant are presented by [K. Roik, G. Hanswille and J. Kina, Solution for the lateral torsional buckling problem of composite beams (in German), Stahlbau 59 (1990)] and [G. Hanswille, J. Lindner and D. Munich, Lateral torsional buckling of composite beams (in German), Stahlbau 67 (1998)]. In the present work, a new procedure is developed to determine the elastic critical moment of lateral–distortional buckling of composite beams under uniform hogging moment. To assess and calibrate this procedure, 7[Formula: see text]772 numerical models were analyzed by the finite element code ANSYS and the results were compared with the ones obtained from the new proposed formulas. The procedure presented excellent agreement with the numerical results, with an average deviation of 2.33% from the computational simulations. The formulations of [K. Roik, G. Hanswille and J. Kina, Solution for the lateral torsional buckling problem of composite beams (in German), Stahlbau 59 (1990)] and [G. Hanswille, J. Lindner and D. Munich, Lateral torsional buckling of composite beams (in German), Stahlbau 67 (1998)] did not lead to such satisfactory results, presenting an average deviation of 12.41% and 16.51%, respectively.


Author(s):  
O. S. Molodid

The paper presents the results of technical and economic indicators study of reinforcing monolithic reinforced concrete slab various methods, namely: the supply of metal beams with the installation of additional supports, external reinforcement of stretched zones using MAPEI technology, adhesion of metal plates and carbon fiber to the developed technology. There is established that the highest indicators of the materials cost, labor intensity and wages for the execution of works relate to the option of reinforcing the floor slab by supplying metal structures, and the lowest indicators have options for reinforcing the floor slabs using MAPEI technology and bonding carbon fiber under the developed technology. The cost of materials for reinforcing the plate in the developed technology with the adhesion of steel plates is the lowest, but complexity, wages and the duration of the work on this technology are much higher than other studied technologies of external reinforcement.


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