Cyclic performance of frames with prestressed steel–concrete composite beams

2008 ◽  
Vol 35 (10) ◽  
pp. 1064-1075
Author(s):  
Weichen Xue ◽  
Kun Li ◽  
Renguang Zheng ◽  
Liang Li

This paper presents a study of the cyclic performance of moment-resisting frames with prestressed steel–concrete composite beams subjected to cyclic displacement reversals. The failure patterns, failure mechanism, hysteretic model, ductility, energy dissipation capacity, stiffness degradation, and deformation-restoring capacity of two composite frames are discussed. Larger slip could be observed along the beam span of the frame with the common composite beam in comparison with the prestressed composite beam. A four-linear hysteretic model with descending branches and two pinching pivot points is proposed for the two composite frames. Tests show that both the test frames failed in a beam side-sway mechanism within the plane of the frame, and the frame with the prestressed composite beam develops relatively high deformation restoring capacity. The applied prestressing in the composite beam has a small contribution to cyclic behavior of the composite frame. Studies also show that more energy is dissipated by the frame with the prestressed composite beam than that with the common composite beam.

2011 ◽  
Vol 80-81 ◽  
pp. 596-600
Author(s):  
Xiang Fei Ye ◽  
Shao Wei Hu

In order to research that how the degree of shear connection influence the static properties of composite beams such as the relative slip on the interface、bearing capacity and failure mode, four prestressed composite beams with different the degree of shear connection were designed, and were loaded on the two symmetric position. The paper described and analyzed the bending behaviors of prestressed composite beam such as the strain distribution of sections、interface slip、deformation and failure patterns on the base of the experimental results. In addition, the paper revised the calculating formulas of the ultimate bending capacity of composite beams with partial shear connection in Eurocode 4 with the least square method combined with test results of domestic and overseas about seven composite beams. The results showed that the correction values were corresponding well with experimental data and the engineering accuracy.


1976 ◽  
Vol 3 (4) ◽  
pp. 514-522 ◽  
Author(s):  
M. N. El-Ghazzi ◽  
H. Robinson ◽  
I. A. S. Elkholy

The longitudinal shear failure of the slab of composite beams is constrained to occur at a predetermined shear surface. A method for calculating the longitudinal shear capacity of the slab of simply-supported steel–concrete composite beams is presented. The method is based on analyzing the stresses at failure of the concrete elements located at the slab shear surface.A design chart based on estimating the transverse normal stress required within the concrete slab to achieve the full ultimate flexural capacity of the composite beam is proposed. Alternatively, using elastic–plastic stress distribution across the concrete slab, the longitudinal compressive force due to bending and hence the applied moment can be predicted for any longitudinal shear capacity of the slab. The proposed design and analysis when compared to previous tests and analysis showed good agreement.The slab width and the shear span of the composite beam are found to be two important parameters which cannot be neglected when estimating the longitudinal shear capacity of the slab. These two parameters have been neglected in the empirical solutions previously adopted.


2017 ◽  
Vol 893 ◽  
pp. 380-383
Author(s):  
Jun Xia ◽  
Z. Shen ◽  
Kun Liu

The tapered cross-section beams made of steel-concrete composite material are widely used in engineering constructions and their dynamic behavior is strongly influenced by the type of shear connection jointing the two different materials. The 1D high order finite element model for tapered cross-section steel-concrete composite material beam with interlayer slip was established in this paper. The Numerical results for vibration nature frequencies of the composite beams with two typical boundary conditions were compared with ANSYS using 2D plane stress element. The 1D element is more efficient and economical for the common tapered cross-section steel-concrete composite material beams in engineering.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2632
Author(s):  
Yafeng Hu ◽  
Yang Wei ◽  
Si Chen ◽  
Yadong Yan ◽  
Weiyao Zhang

A timber–lightweight−concrete (TLC) composite beam connected with a ductile connector in which the ductile connector is made of a stainless−steel bolt anchored with nuts at both ends was proposed. The push−out results and bending performance of the TLC composite specimens were investigated by experimental testing. The push−out results of the shear specimens show that shear–slip curves exhibit good ductility and that their failure can be attributed to bolt buckling accompanied by lightweight concrete cracking. Through the bending tests of ten TLC composite beams and two contrast (pure timber) beams, the effects of different bolt diameters on the strengthening effect of the TLC composite beams were studied. The results show that the TLC composite beams and contrast timber beams break on the timber fiber at the lowest edge of the TLC composite beam, and the failure mode is attributed to bending failure, whereas the bolt connectors and lightweight concrete have no obvious breakage; moreover, the ductile bolt connectors show a good connection performance until the TLC composite beams fail. The ultimate bearing capacities of the TLC composite beams increase 2.03–3.5 times compared to those of the contrast beams, while the mid-span maximum deformation decrease nearly doubled.


2018 ◽  
Author(s):  
◽  
Ayman Elzohairy

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The steel-concrete composite beam represents a structural system widely employed in both buildings and girder bridges. The coupling between steel beams and concrete flanges assures both economic and structural benefits because of quick construction of steel structures and large increase in stiffness due to the presence of concrete. Strengthening with external post-tensioning (PT) force is particularly effective and economical for long-span steel-concrete composite beams and has been employed with great success to increase the bending and shear resistance and correct excessive deflections. Applying external PT force to the steel-concrete composite beam is considered an active strengthening technique that can create permanent internal straining action in the beam which is opposite to the existing straining action due to the applied service loads. The most benefits of using this system of strengthening are an elastic performance to higher loads, higher ultimate capacity, and reduction in deformation under the applied loads. Under service loads, bridge superstructures are subjected to cyclic loads which may cause a premature failure due to fatigue. Therefore, fatigue testing is critical to evaluate existing design methods of steel-concrete composite beams. ... This research presents static and fatigue tests on four steel-concrete composite specimens to evaluate the effect of externally post-tensioned tendons on the ultimate strength and fatigue behavior of composite beams. Fatigue tests are conducted to a million cycles under a four-point bending test. In addition, final static tests are performed on fatigued specimens to evaluate the residual strength of the strengthened specimen. A numerical model is described to predict the fatigue response of the composite beam by considering the fatigue damage in the concrete flange. The accuracy of the developed numerical model is validated using the existing test data. The static test results indicate that the external post-tensioning force improves the flexural behavior of the strengthened specimen by increasing the beam capacity and reducing the tensile stress in the bottom flange of the steel beam. The fatigue results demonstrate that the external post-tensioning significantly decreases the strains in the shear connectors, concrete flange, and steel beam. The tendons demonstrated an excellent fatigue performance, with no indication of distress at the anchors.


2020 ◽  
Vol 8 (5) ◽  
pp. 3559-3565

In this Paper, the analysis of simply supported laminated composite beam having uniformly distributed load is performed. The solutions obtained in the form of the displacements and stresses for different layered cross ply laminated composite simply supported beams subjected uniformly distributed to load. Different aspect ratio consider for different results in terms of displacement, bending stress and shear stresses. The shear stresses are calculated with the help of equilibrium equation and constitutive relationship. Using displacement field including trigonometric function of laminated composite beams are derived from virtual displacement principle. There are axial displacement, transverse displacement, bending stress and shear stresses. In addition, Euler-Bernoulli (ETB), First order shear deformation beam theory (FSDT), Higher order shear deformation beam theory (HSDT) and Hyperbolic shear deformation beam theory (HYSDT) solution have been made for comparison and better accuracy of solutions and results of static analyses of laminated composite beams for simply supported laminated composite beam.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zhangqi Hu ◽  
Ran He ◽  
Yukui Wang ◽  
Weirong Lv ◽  
Jingchao Li

This paper proposes a novel U-shaped steel-encased concrete composite beam-girder joint (referred to herein as the novel composite beam-girder joint), in which the U-shaped beams at two sides (L and R) are inserted into a shaped sleeve, and the U-shaped girder and two U-shaped beams are connected by the shaped sleeve through welding. Compared with the traditional beam-girder joints, the novel composite beam-girder joints take advantage of easy construction, light weight, and short construction period. The failure patterns, load-strain and load-deflection curves, and strain distributions of the novel composite beam-girder joints were investigated through the static loading tests on two full-scale specimens, denoted as GBJ1 and GBJ2. The two specimens were varied in beam section reinforcements. Specimen GBJ2 was equipped with 3Ф16 additional bars in the U-shaped beams based on Specimen GBJ1. Test results show that the two specimens failed as the through arc cracks developed at the concrete slab interfaces. The additional bars can increase the bearing capacity slightly but will also increase the stress concentration on the bottom flange of the shaped sleeve, leading to the decrease of ductility for Specimen GBJ2. The slab effect is considered in the test and can thus reflect the actual stress state of the beam-girder joints well. This study can provide a reference for the design and application of beam-girder joints.


2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Boxin Wang ◽  
Ruichang Fang ◽  
Qing Wang

Given the excellent crack resistance performance of steel fiber-reinforced self-stressing concrete (SFRSSC), the bending performance of some composite beams with SFRSSC laminated layers was studied. The experiment conducted in this study comprised a single-span composite beam test (including 3 test beams) and a two-span continuous composite beam test (including 2 test beams). All the test beams were T-shaped. The cracking load, yielding load, and ultimate load of all the test beams were recorded and comparatively analyzed. Experimental results showed that the cracking load of the test beam with an SFRSSC laminated layer is significantly increased. Mechanical analysis and numerical simulation of the test beams were conducted, and the obtained results agreed well with the experimental results. The composite beams under different working conditions were also numerically simulated. Through the simulation, reasonable ranges of precompressive stress and length of the SFRSSC laminated layer at intermediate support of continuous composite beam were obtained.


2020 ◽  
Vol 211 ◽  
pp. 110471 ◽  
Author(s):  
Youzhu Lin ◽  
Jiachuan Yan ◽  
Zefang Wang ◽  
Feng Fan ◽  
Yue Yang ◽  
...  

2020 ◽  
Vol 12 (20) ◽  
pp. 8328 ◽  
Author(s):  
Tomas Kinderis ◽  
Mindaugas Daukšys ◽  
Jūratė Mockienė

Over the past decade, several types of composite slim floor constructions have been used in multi-storey buildings in Lithuania. In order to study the efficiency of composite beam application in steel-framed multi-storey buildings, Thorbeam (A1), Deltabeam (A2), slim floor beam (A3) and asymmetric slim floor beam (A4) were chosen and evaluated according to nine assessment criteria (beam cost (K1), initial preparation on site (K2), installation time (K3), complexity of installation technology (K4), labour costs (K5), fire resistance (K6), load bearing capacity (K7), beam versatility (K8), and availability of beams (K9)). First, the significance of the rating criteria was selected and the order of the ranking criteria was obtained (K1˃K7˃K3˃K6˃K4˃K5˃K2˃K8˃K9) by means of a survey questionnaire. Second, the beams were ranked according to the points given by the questionnaire respondents as follows: 160 points were given to A2, 144 points to A1, 129 points to A4, and 111 points to A3. Deltabeam is considered to be the most rational alternative of the four beams compared. Calculations done using the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) analysis method revealed that composite beam A2 was the best slim floor structure alternative for an eight-storey high-rise commercial residential building frame, A1 ranked second, A4 ranked third, and A3 ranked fourth. In addition, the four composite beams were compared to a reinforced concrete beam (A5) according to three assessment criteria (beam cost including installation (C1), beam self-weight (C2) and fire resistance (C3)). Deltabeam was found to be efficient for use as a slim floor structure in a multi-story building due to having the lowest cost, including installation, and self-weight, and the highest fire resistance compared to other composite beams studied. Although Deltabeams are 1.4 times more expensive than reinforced concrete beams, including installation costs, they save about 2.5% of the building’s height compared to reinforced concrete beams.


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