scholarly journals Behavior of the T-Shaped Concrete-Filled Steel Tubular Columns after Elevated Temperature

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Xianglong Liu ◽  
Jicheng Zhang ◽  
Hailin Lu ◽  
Ning Guan ◽  
Jiahao Xiao ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Bearing Capacity ◽  
Failure Modes ◽  
Shear Failure ◽  
Element Model ◽  
Ultimate Bearing Capacity ◽  
Steel Tubes ◽  
Tubular Columns ◽  
Short Columns ◽  
Experimental Values

The mechanical properties of T-shaped concrete-filled steel tubular (TCFST) short columns under axial compression after elevated temperature are investigated in this paper. A total of 30 TCFST short columns with different temperature (T), steel ratio (α), and duration of heating (t) were tested. The TCFST column was directly fabricated by welding two rectangular steel tubes together. The study mainly investigated the failure modes, the ultimate bearing capacity, the load-displacement, and the load-strain performance of the TCFST short columns. Experimental results indicate that the rectangular steel tubes of the TCFST column have deformation consistency, and the failure mode consists of local crack, drum damage, and shear failure. Additionally, the influence of high temperature on the residual bearing capacity of the TCFST is significant, e.g., a higher temperature can downgrade the ultimate bearing capacity. Finally, a finite element model (FEM) is developed to simulate the performance of the TCFST short columns under elevated temperature, and the results agree with experimental values well. Overall, this investigation can provide some guidance for future studies on damage assessment and reinforcement of the TCFST columns.

scholarly journals Experimental Investigation on Web Crippling Property of High-Strength Cold-Formed (HSCF) Rectangular Steel Tube

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xianglong Liu ◽  
Jicheng Zhang ◽  
Yuanqi Li ◽  
Lei Zeng ◽  
Guofeng Du
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
High Strength ◽  
Ultimate Bearing Capacity ◽  
Height Ratio ◽  
Steel Tubes ◽  
Web Crippling ◽  
Bearing Plate ◽  
Bearing Load ◽  
Plate Width

To research the web crippling performance (i.e., the ultimate web crippling bearing capacity and ductility) of high-strength cold-formed (HSCF) rectangular steel tubes under concentrated load, thirty-six specimens with different bearing plate width, width-to-height ratio, boundaries, and loading conditions are fabricated and tested in this paper. Particularly, four kinds of boundaries and loading conditions are utilized, including end-two-flange (ETF), end-one-flange (EOF), interior-two-flange (ITF), and interior-one-flange (IOF). Research revealed the failure modes of HSCF rectangular steel tubes under concentrated loads applied at the end or interior. Moreover, the load-displacement curves and load-strain curves are obtained. The results show that the ultimate crippling capacity of webs increases significantly with larger bearing plate width and width-to-height ratio. Specimens subjected to interior bearing load have higher ultimate strength and deformation capacity than counterparts that are subjected to bearing load at the end. Additionally, in the middle of the compression web, all strain measuring points enter the plasticity stage and finally appear in the plastic hinge area. Subsequently, the failure modes and ultimate bearing capacity are simulated by the finite element method (FEM), which is implemented via ABAQUS. By comparing the test results with the numerical values, demonstrate the effectiveness of the proposed numerical simulation on investigating the failure modes and the ultimate bearing capacity of HSCF rectangular steel tubes. Finally, regarding the conservative and dangerous calculation of web crippling ultimate bearing capacity in current codes, we can provide a good guidance for future work, particularly the proposed calculation equations for ultimate bearing capacity of HSCF rectangular steel tubes.

scholarly journals BUCKLING OF SLENDER COMPOSITE CONCRETE‐FILLED STEEL COLUMNS

2010 ◽  
Vol 16 (2) ◽  
pp. 230-236 ◽  
Author(s):  
C. Douglas Goode ◽  
Artiomas Kuranovas ◽  
Audronis Kazimieras Kvedaras
Keyword(s):  
Bearing Capacity ◽  
Steel Tubes ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Hollow Section ◽  
Steel Columns ◽  
Tubular Columns ◽  
Cylinder Strength ◽  
Experimental Values ◽  
Concrete Filled Steel Tubes

The paper presents the analysis of the experimental data of 1817 on concrete‐filled steel tubes ‐ CFSTs. These results are compared with the predicted results of the load‐bearing capacity of calculations of slender elements according to the methods suggested by Eurocode 4. The following types of tested CFSTs were analysed: circular and rectangular hollow section stub and long columns fully filled with concrete, which were with or without applied moments at the ends of specimen. During the results obtained in the result of the tests on the load bearing capacity for circular concrete‐filled steel tubular columns correspond with the calculated values based on methods presented by Eurocode 4. The experimental values of load bearing capacity for members of concrete‐filled rectangular hollow sections agree very well with the theoretical values where the concrete cylinder strength is below 75 N/mm2. The analysis demonstrated that preloading of concrete‐filled hollow section members does not influence the load bearing capacity. This paper also presents the examination of stress state distribution for concrete‐filled hollow section members, influence of concrete preloading and of longitudinal stress strain curves. Santrauka Straipsnyje aptariami 1817 betonšerdžiu plieniniu vamzdiniu strypu eksperimentiniai duomenys. Šie duomenys lyginami su rezultatais, gautais remiantis Eurocode 4 pateiktais kompozitiniu elementu laikomosios galios nustatymo metodais. Analizuojami tokie betonšerdžiu plieniniu strypu bandiniu tipai: pilnavidures trumpos arba liaunos apskritojo ir stačiakampio skerspjūvio vamzdines betonšerdes plienines kolonos su ju galuose veikiančiu lenkiamuoju momentu arba be jo. Apskritojo skerspjūvio betonšerdžiu kolonu bandymu metu gautieji laikomosios galios rezultatai atitinka remiantis Eurocode 4 pateiktais metodais apskaičiuotasias ju reikšmes. Stačiakampio skerspjūvio betonšerdžiu elementu laikomosios galios bandymais rastosios reikšmes labai gerai atitinka teorines reikšmes, kai šerdies betono ritininis stipris nesiekia 75 N/mm2. Analizuojant nustatyta, kad išankstinis betonšerdžiu elementu apkrovimas neturi beveik jokio poveikio elementu laikomajai galiai. Šiame straipsnyje taip pat nagrinejamas betonšerdžiu elementu itempiu būviu pasiskirstymas, betono apspaudimo poveikis bei išilginiu deformaciju ir itempiu kreives.

Experimental Research on Joints Behavior of Concrete-Filled Steel Tubular Columns

2013 ◽  
Vol 446-447 ◽  
pp. 1409-1412
Author(s):  
Mei Li He ◽  
Hua Long Yu ◽  
Yan Cao ◽  
Yong Kang Xia
Keyword(s):  
Mechanical Properties ◽  
Yield Point ◽  
Experimental Research ◽  
Failure Modes ◽  
Shear Failure ◽  
Tubular Columns ◽  
Short Columns ◽  
Compressive Tests

By means of eccentric compressive tests of Concrete-filled Steel Tubular Columns, to research the mechanical properties and failure modes of Concrete-filled Steel Tubular Columns without yield point. Research shows that, the failure modes of axial compressive Concrete-filled Steel Tubular Columns without yield point, as well as axial compressive short columns, have the same trend of oblique shear failure.

Seismic Experiments for Multi-Ribbed Sandwich Insulation Composite Wallboard

2012 ◽  
Vol 174-177 ◽  
pp. 701-705
Author(s):  
Ya Feng Yue ◽  
Wei Huang ◽  
Dong Zhao
Keyword(s):  
Mechanical Properties ◽  
Energy Dissipation ◽  
Bearing Capacity ◽  
Failure Modes ◽  
Shear Failure ◽  
Low Frequency ◽  
Ultimate Bearing Capacity ◽  
Horizontal Load ◽  
Initial Stiffness

Low frequency cyclic horizontal load experiments have been carried out on the sandwich insulation (ECW-8) and ordinary (ECW-1) multi-ribbed composite wallboard. Mechanical properties of two specimens such as bearing capacity, energy dissipation and failure modes were studied. Two specimens are both shear failure. The cracking load of insulation wallboard increases by 29.1% than ordinary wallboard. The initial stiffness of insulation wallboard is 1.38 times of ordinary wallboard. The ultimate bearing capacity and energy dissipation performance has little difference between them.

Study of Failure Modes of Suction Anchors

2011 ◽  
Author(s):  
Qiyi Zhang ◽  
Sheng Dong
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Failure Modes ◽  
Limit Equilibrium ◽  
Element Model ◽  
Ultimate Bearing Capacity ◽  
Engineering Practice ◽  
Element Analysis ◽  
Limit Equilibrium State

Suction foundations are widely used in deep sea and their ultimate bearing capacity which is closely related with failure modes of suction anchor at limit equilibrium state is a key technology in offshore engineering practice. Based on Coulomb friction theory, an exact finite element model is presented in this paper. On the basis of this FEM model, by use of the finite element analysis software ABAQUS, the effect of mooring point and aspect ratio of a suction anchor on the ultimate bearing capacity and its stability are researched in detail. The results show that the ultimate bearing capacity and stability of the suction anchor are affected vastly by the position of mooring point, and the variation of mooring point on the suction anchor can lead to different failure modes. Simultaneously, the results also shows that tilted rotation of the soil along the direction of the mooring force will occur when the mooring point is near the top of the suction anchor, and the soil near the bottom of the fixed anchor rotates around the center of a circle, so the failure mode is called forward-tilted rotation in this paper; A general translation slip of the soil in front of the anchor along the direction of the mooring force will occur when mooring point is below midpoint of suction anchor, so the failure mode is called the translation slip failure mode in this paper. Anticlockwise tilted rotation of the soil along the direction of mooting force will occur when the mooring point is near the bottom of the anchor, and the soil at the top of the anchor rotates around the center of a circle, so the failure mode is called backward-tilted rotation in this paper.

scholarly journals Eccentric Compressive Behavior of Round-Ended Rectangular Concrete-Filled Steel Tubes with Different Central Angles

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 456
Author(s):  
Zhigang Ren ◽  
Qi Li ◽  
Gaoyu Wang ◽  
Wei Wei ◽  
Mohammed A. A. M. Abbas
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Ultimate Bearing Capacity ◽  
Confinement Effect ◽  
Interfacial Stress ◽  
Steel Tubes ◽  
Cross Sectional ◽  
Aspect Ratios ◽  
Material Utilization ◽  
Concrete Filled Steel Tubes

The application of round-ended rectangular concrete-filled steel tubes (RRCFSTs) in high-rise buildings or bridge structures is increasing, improving structural performance and meeting aesthetic requirements. Researching this novel steel–concrete composite helps to fully utilize the properties of the materials. In this study, 15 specimens were tested for analysis of the behaviors of RRCFSTs with different central angles under eccentric compression. Influences of central angles of round ends (θ), aspect ratios of rectangular parts (κ), steel strength and the eccentric ratio on failure modes, material utilization, confinement effect and eccentric bearing capacity are studied. Besides, the mechanism of confinement effects of steel tubes with different θ values was evaluated with the finite element method (FEM). The results show that local bulking usually occurs at the compression zone. When θ gradually changes from 0° to 180°, the local bulking position of straight steel plate changes from mid-length to both ends of the columns. Additionally, the interfacial stress between steel tube and concrete at round ends rises, but that at the corner, it decreases continuously, which results in an improved overall confinement effect and increased material utilization. In contrast, a larger κ leads to lower material efficiency because of the reduced overall confinement effect. The increases in both θ and κ enlarge the cross-sectional area and the eccentric ultimate bearing capacity, whereas θ has a better influence on the ductility than κ. A feasible simplified calculating approach for the eccentric ultimate bearing capacity of RRCFSTs is presented and validated.

Experimental Studies on Axially Loaded Concrete Columns Confined by Different Materials

2008 ◽  
Vol 400-402 ◽  
pp. 513-518 ◽  
Author(s):  
Yong Chang Guo ◽  
Pei Yan Huang ◽  
Yang Yang ◽  
Li Juan Li
Keyword(s):  
Bearing Capacity ◽  
Glass Fiber ◽  
Failure Modes ◽  
Experimental Studies ◽  
Concrete Columns ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Advantages And Disadvantages ◽  
Axially Loaded ◽  
Normal Strength

The improvement of the load carrying capacity of concrete columns under a triaxial compressive stress results from the strain restriction. Under a triaxial stress state, the capacity of the deformation of concrete is greatly decreased with the increase of the side compression. Therefore, confining the deformation in the lateral orientation is an effective way to improve the strength and ductility of concrete columns. This paper carried out an experimental investigation on axially loaded normal strength concrete columns confined by 10 different types of materials, including steel tube, glass fiber confined steel tube (GFRP), PVC tube, carbon fiber confined PVC tube (CFRP), glass fiber confined PVC tube (GFRP), CFRP, GFRP, polyethylene (PE), PE hybrid CFRP and PE hybrid GFRP. The deformation, macroscopical deformation characters, failure mechanism and failure modes are studied in this paper. The ultimate bearing capacity of these 10 types of confined concrete columns and the influences of the confining materials on the ultimate bearing capacity are obtained. The advantages and disadvantages of these 10 types of confining methods are compared.

Research of Post-Fire Mechanical Property of Steel Fiber Reinforced Ceramsite Concrete Filled Steel Tubes after Exposure to Fire

2013 ◽  
Vol 790 ◽  
pp. 181-184
Author(s):  
Hai Lun Tong ◽  
Tian Hong Wang ◽  
Jian Qi Lu ◽  
Xin Tang Wang
Keyword(s):  
Bearing Capacity ◽  
Steel Fiber ◽  
Fiber Reinforced ◽  
Fire Load ◽  
Furnace Temperature ◽  
Steel Tubes ◽  
Compression Performance ◽  
Short Columns ◽  
Maximum Value ◽  
Concrete Filled Steel Tubes

The post-fire axial compressive behavior of a set of steel fiber reinforced ceramsite concrete filled steel tubular short columns (noted as SFCC-SSC) was experimentally studied. Effect of the maximum value of fire response temperatures of the specimens and some parameters on the axial compression performance of the specimens was especially discussed. The results show that the surface of the steel tubes after fire presented dark red for 700°Cof furnace temperature and orange red for 900°C, and there was no obvious descending segment in post-fire load-displacement curves of the most specimens subjected to fire load. It was concluded that the axial bearing capacity of the specimens aftersuffering the furnace temperature of 900°C is much less than that of the specimens not subjected to fire load, and the volume of steel fiber of 0.5% of has the greatest effect on post-fire bearing capacity of specimens of SFCC-SSC.

A numerical approach to predict soil bearing potential for isolated footing

2021 ◽  
Author(s):  
Gilbert Hinge ◽  
Jayanta Kumar Das ◽  
Biswadeep Bharali
Keyword(s):  
Bearing Capacity ◽  
Shear Failure ◽  
Correlation Coefficients ◽  
Failure Criteria ◽  
Numerical Approach ◽  
Ultimate Bearing Capacity ◽  
Foundation Design ◽  
Advantages And Disadvantages ◽  
Local Shear ◽  
Failure Conditions

<p>The success of any civil engineering structure's foundation design depends upon the accuracy of estimation of soil’s ultimate bearing capacity. Numerous numerical approaches have been proposed to estimate the foundation's bearing capacity value to avoid repetitive and expensive experimental work. All these models have their advantages and disadvantages. In this study, we compiled all the governing equations mentioned in Bureau of Indian standard IS:6403-1981 and modify the equation for Ultimate Bearing Capacity. The equation was modified by considering two new parameters, K1(for general shear) and K2 (for local shear) so that a common governing equation can be used for both general and local shear failure criteria. The program used for running the model was written in MATLAB language code and verified with the observed field data. Results indicate that the proposed model accurately characterized the ultimate, safe, and allowable bearing capacity of a shallow footing at different depths. The correlation coefficients between the observed and model-predicted bearing capacity values for a 2m foundation depth with footing size of 1.5 ×1.5, 2.0 × 2.0, and 2.5 × 2.5 m are 0.95, 0.94, and 0.96. A similar result was noted for the other foundation depth and footing size. Findings show that the model can be used as a reliable tool for predicting the bearing capacity of shallow foundations at any given depth.  Moreover, the formulated model can also be used for the transition zone between general and local shear failure conditions.</p>

scholarly journals Experimental Study on the Shear Performance of Steel-Truss-Reinforced Concrete Beam-Column Joints

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Dafu Cao ◽  
Jiaqi Liu ◽  
Wenjie Ge ◽  
Rui Qian
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Compression Ratio ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Ultimate Bearing Capacity ◽  
Shear Capacity ◽  
Core Area ◽  
Axial Compression Ratio ◽  
Steel Truss

In order to study the influence of the axial compression ratio and steel ratio on the shear-carrying capacity of steel-truss-reinforced beam-column joints, five shear failure interior joint specimens were designed. The effect of different coaxial pressure ratios (0.1, 0.2, and 0.3) and steel contents on the strain, ultimate bearing capacity, seismic performance, and failure pattern of cross-inclined ventral and chord bars in the joint core area was investigated. The experimental results show that the load-displacement hysteretic curves of all test specimens exhibit a bond-slip phenomenon. With the increase of the axial compression ratio, the ultimate bearing capacity of the joint core increases by 3.4% and 5.9%, respectively. While the ductility decreases by 10.3% and 13.1%, and the energy consumption capacity decreases by 3.2% and 5.8%, respectively. The shear capacity and ductility of the member with cross diagonal ventral steel angle in the joint core are increased by 12.9% and 13.4%, respectively. The shear capacity and ductility of the joint can be significantly improved by increasing the amount of steel in the core area. The expression of shear capacity suitable for this type of joint is obtained by fitting analysis, which can be used as a reference for engineering design.

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