Статті в журналах: "Concrete-filled double steel tubular columns"

1

T, Sreelakshmi, and Divya K K. "Study on Axial Load Carrying Capacity of Concrete-Filled Double Skin Slender Waist-Shaped Stub Column." International Journal for Research in Applied Science and Engineering Technology 10, no. 6 (June 30, 2022): 4915–19. http://dx.doi.org/10.22214/ijraset.2022.45114.

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Abstract: In the present scenario, concrete-filled steel tubular members have become very popular in the construction industry. These types of members utilize both the advantages of steel and concrete such as the high strength and ductility of steel and the high strength and stiffness of concrete. In the present concrete-filled double skin slender waist-shaped column is used. These columns are composed of two steel tubes such that they are arranged in a concentric configuration with concrete sandwiched between them. It has the ability to impart equal or superior characteristics when compared to traditional concrete-filled steel tubular columns. The finite element method using ANSYS software is used for the study. In this work, the nonlinear structural behavior of CFDST columns is investigated by varying the cross-sectional shapes of steel tubes used. Various parameters that can be evaluated from this study are stress, strain, and deformation values. Comparative results of values of these parameters are obtained.

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2

Ci, Junchang, Mizan Ahmed, Viet-Linh Tran, Hong Jia, and Shicai Chen. "Axial compressive behavior of circular concrete-filled double steel tubular short columns." Advances in Structural Engineering 25, no. 2 (October 19, 2021): 259–76. http://dx.doi.org/10.1177/13694332211046345.

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This article investigates the axial compressive performance of concrete-filled double steel tubular (CFDST) short columns composed of circular section loaded concentrically. An experimental program comprised of compression tests on short columns is carried out to examine their structural performance. Axial compression tests on conventional concrete-filled steel tubular (CFST) columns and double-skin concrete-filled steel tubular (DCFST) columns are also performed for comparison purposes. The test parameters include the diameter-to-thickness of the outer and inner steel tubes, concrete strength, and diameter ratio. The test results exhibit that CFDST short columns composed of the circular section have improved structural performance compared to its CFST and DCFST counterparts. A theoretical model is also presented to simulate the test ultimate strengths and load-axial strain relationships of CFDST columns. The existing design models proposed including the codified design specifications are evaluated against the collected test data for predicting the axial compressive strengths of circular CFDST columns. It is seen that the existing codified design models cannot yield their ultimate axial compressive strengths accurately. A practical artificial neural network (ANN) model is proposed to estimate the ultimate load of such columns loaded concentrically.

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3

Bhatia, Sakshi, and Aditya Kumar Tiwary. "Concrete Filled Double Skinned Tubular Columns Subjected to Different Loading Conditions." IOP Conference Series: Earth and Environmental Science 889, no. 1 (November 1, 2021): 012050. http://dx.doi.org/10.1088/1755-1315/889/1/012050.

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Abstract The meteoric growth in light weight structures have opened on doors to many revolutionary concepts and innovations. Studies have manifested that the lowered weight of the structures somehow help to fight the material cost with a better seismic performance. The hollow core structures aimed reducing the structural weight with an improved structural performance as well. The Concrete filled double steel tubes (CFDST) can be taken as amalgamation of Hollow core columns and CFST i.e. single skinned columns. The co-relation of CFST and Hollow core columns gave birth to Concrete filled double skinned tubular columns (CFDST) which can possess the advantages of both the concepts. A sedulous review of concrete filled double skinned columns is being conveyed through this article. The behavior of confined concrete as well as the confining inner and outer steel in the CFDST model and its overall structural behavior is being succinctly reviewed in this article and a simultaneous comparison of CFDST columns to solid concrete/conventional columns is also being carried out where required.

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4

Javed, Muhammmad Faisal, Haris Rafiq, Mohsin Ali Khan, Fahid Aslam, Muhammad Ali Musarat, and Nikolai Ivanovich Vatin. "Axial Behavior of Concrete-Filled Double-Skin Tubular Stub Columns Incorporating PVC Pipes." Crystals 11, no. 12 (November 23, 2021): 1434. http://dx.doi.org/10.3390/cryst11121434.

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This experimental study presents concrete-filled double-skin tubular columns and demonstrates their expected advantages. These columns consist of an outer steel tube, an inner steel tube, and concrete sandwiched between two tubes. The influence of the outer-to-inner tube dimension ratio, outer tube to thickness ratio, and type of inner tube material (steel, PVC pipe) on the ultimate axial capacity of concrete-filled double-skin tubular columns is studied. It is found that the yield strength of the inner tube does not significantly affect the ultimate axial capacity of concrete-filled double-skin tubular composites. With the replacement of the inner tube of steel with a PVC pipe, on average, less than 10% strength is reduced, irrespective of size and dimensions of the steel tube. Hence, the cost of a project can be reduced by replacing inner steel tubes with a PVC pipes. Finally, the experimental results are compared with the existing design methods presented in AISC 360-16 (2016), GB51367 (2019), and EC4 (2004). It is found from the comparison that GB51367 (2019) gives better results, followed by AISC (2016) and EC4 (2004).

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5

Cong, Shu Ping, Teng Li, and Jin Sheng Han. "Study on Section Temperature Field of Concrete-Filled Double Steel Tubular Columns under Fire." Advanced Materials Research 1065-1069 (December 2014): 1125–28. http://dx.doi.org/10.4028/www.scientific.net/amr.1065-1069.1125.

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Finite element model was built in order to study the section temperature field of concrete-filled double steel tubular columns through the software of ANSYS. Moisture of concrete and thermal contact resistance were considered in the model. Based on the Eurocode 2, specific heat of concrete was modified in order to consider the effect of moisture. Contact elements were created in the interface between steel tube and concrete in order to consider the effect of thermal contact resistance. The effects of diameter of steel tube and type of aggregate to section temperature field were studied. Distribution of section temperature field is given on the concrete-filled double steel tubular columns, which provides the basis for the analysis of fire resistance capability.

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6

Wang, Xin. "Mechanical Behavior of Concrete-Filled Double Steel Tubular Columns under Axial Compression Load." Applied Mechanics and Materials 166-169 (May 2012): 3184–88. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.3184.

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This article analyzes five concrete-filled double steel tubular column models based on the large finite element analysis software ABAQUS. An axial compression test was carried out on specimens with different diameter-thickness ratio of internal steel tube in order to get the whole longitudinal load-displacement curves and the whole load- strain curves for internal and external steel tube and concrete. We get the ultimate bearing capacity for five specimens, the result of simulation agree well with the theoretical calculation data, that provide reliable data for concrete-filled double steel tubular column in respect of finite element (FE) simulation.

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7

Ge, Qing Yun, Cai Mei Li, and Fu Lian Yang. "The Study on Bearing Capacity of Concrete-Filled Double Skin Steel Tubular Columns of Octagon Section under Axial Compression." Advanced Materials Research 671-674 (March 2013): 936–39. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.936.

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Based on unified strength theory solution of thickness cylinder, according to the introducing concrete strength reduction factor and equivalent restriction factor, this paper deduced the axial compressive bearing capacity formula of concrete-filled double skin steel tubular columns of octagon section. Compared the results of the paper with the experiment results，both coincide in good condition. The results show that the theoretical formula are correct and viable. The theoretical formula is expected to provide a theoretical foundation to the research of concrete-filled double skin steel tubular columns of octagon section.And it provides references for the engineering design.

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8

Louk Fanggi, Butje Alfonsius, and Togay Ozbakkloglu. "Influence of Inner Steel Tube Diameter on Compressive Behavior of Square FRP-HSC-Steel Double-Skin Tubular Columns." Advanced Materials Research 1119 (July 2015): 688–93. http://dx.doi.org/10.4028/www.scientific.net/amr.1119.688.

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FRP-concrete-steel double-skin tubular columns (DSTCs) are a new form composite column system that effectively combines the advantages of the constituent materials. The performance of this column system has been experimentally investigated in a number of recent studies. However, apart from a single study reported on square DSTCs, all of the existing studies have been concerned with DSTCs with circular external tubes. This paper reports on part of an ongoing experimental program at the University of Adelaide on FRP-concrete-steel composite columns. The results from 12 square hollow and concrete-filled DSTCs and six companion hollow concrete-filled FRP tubes (H-CFFTs) that were tested under axial compression are presented. Results of the experimental study indicate that hollow DSTCs with larger inner steel tube diameters develop similar ultimate axial stresses to but significantly larger axial strains than companion DSTCs with smaller inner steel tubes. The results also show that, in concrete-filled DSTCs with similar Ds/ts ratios, an increase in the steel tube diameter leads to an increase in both axial stress and strain of concrete. It was observed that H-CFFTs perform significantly worse than both hollow and filled DSTCs under axial compression, and their behavior further degrades with an increase in the diameter of their inner voids.

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9

Cui, Ying, Meimei Song, Zhan Qu, Shanshan Sun, and Junhai Zhao. "Research on Damage Assessment of Concrete-Filled Steel Tubular Column Subjected to Near-Field Blast Loading." Shock and Vibration 2020 (November 23, 2020): 1–19. http://dx.doi.org/10.1155/2020/8883711.

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Concrete-filled steel tubular (CFST) columns are widely used in engineering structures, and they have many different cross section types. Among these, normal solid sections and concrete-filled double-skin steel tubular sections are often used. Although many studies have been conducted on CFST columns with these two section types, no studies have been conducted on their damage assessment under blast loading. In this study, experimental analysis and a numerical simulation method were integrated to evaluate the responses and assess the damage of two concrete-filled steel tubular (CFST) columns with different cross sections subjected to near-field blast loading. The results showed that for a scaled distance of 0.14 m/kg1/3, plastic bending deformation occurred on the surfaces of the two CFST columns facing the explosive. The antiexplosion performance of the normal solid-section (NSS) CFST column was better than that of the concrete-filled double-skin steel tubular (CFDST) column. The explosion centre was set at the same height as the middle of column, and the distributions of the peak pressure values of the two columns were similar: the peak pressures at the middle points of the columns were the greatest, and the peak pressures at the bottom were higher than those at the top. With the analysis of the duration of the positive pressure, the damage at the middle was the most severe when subjected to blast loading. Using pressure-impulse damage theory and the validated numerical simulations, two pressure-impulse damage evaluation curves for NSS and CFDST columns were established separately by analysing the experimental and simulation data. Finally, based on the two pressure-impulse damage evaluation curves, the two pressure-impulse damage criteria for these two different fixed-end CFST columns were defined based on the deflection of the surfaces facing the explosives. Furthermore, the mathematical formulae for the two different column types were established to generate pressure-impulse diagrams. With the established formulae, the damage of the CFST columns with these two cross section types can be evaluated. Damage to other similar CFST columns with different cross section types due to near-field blast loading can also be evaluated by this method.

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10

Simon, Ms Sandra Mariam, and Ms Anju Thulasi. "Non Linear Analysis on CFDST columns with and without GFRP Wrapping." International Journal for Research in Applied Science and Engineering Technology 10, no. 7 (July 31, 2022): 612–16. http://dx.doi.org/10.22214/ijraset.2022.45379.

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Abstract: Concrete Filled Double Skin Steel Tube (CFDST) columns are modified form of Concrete Filled Steel Tubular (CFST) columns, developed by several researchers. CFDST column composed of two concentric steel tubes in which concrete is packed in between them. It is available in various geometrical shapes. CFDST have many advantages such as high strength, high bending stiffness, good seismic and fire performance. But it is found that CFDST columns have some disadvantages including ageing of structures, corrosion of steel tubes etc. which reduces the strength of the column. So, to prevent these drawbacks and to strengthen the structure, Glass Fiber Reinforced Polymer (GFRP) can be used as an external cover. The present study aims to do nonlinear static analysis of CFDST columns having different hollow ratio wrapped with and without GFRP under axial compression using ANSYS finite element analysis software.

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11

İpek, S., and E. M. Güneyisi. "Ultimate Axial Strength of Concrete-Filled Double Skin Steel Tubular Column Sections." Advances in Civil Engineering 2019 (February 3, 2019): 1–19. http://dx.doi.org/10.1155/2019/6493037.

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This study aims at proposing a new model for evaluating the ultimate axial strength of concrete-filled double skin steel tubular (CFDST) composite columns. For this, a total of 103 experimental data regarding the ultimate strength of CFDST columns under axial loading were collected from the previous studies in the literature. All CFDST columns consist of two steel tubes being outer and inner circular hollow section. The model presented herein was developed by using gene expression programming. For this, the yield strength, diameter, and thickness of both outer and inner steel tubes, the compressive strength of annulus concrete, the length of the specimen, and the ultimate axial strength of the columns were utilized as the parameters. Assessment of the obtained results indicated that the generated model had a good performance compared to the existing models by the previous researchers and the equations specified in the design codes. The high value of R2 and narrow ranged fluctuation of the estimation error for the ultimate axial strength of the CFDST columns were also achieved through the proposed model.

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12

Dong, Chun Xiao, and Johnny Ching Ming Ho. "THEORETICAL MODEL FOR DOUBLE-SKINNED CONCRETE-FILLEDSTEEL-TUBULAR COLUMNS WITH EXTERNAL CONFINEMENT." Journal of Civil Engineering and Management 21, no. 5 (May 6, 2015): 666–76. http://dx.doi.org/10.3846/13923730.2014.893913.

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Recent advances in the production of super-fine cement and filler technology has made the production of high-strength concrete (HSC) of 120 MPa practicable in the industry. Nonetheless, the application of such HSC in real construction is still limited. One of the reasons that inhibits the use of HSC is the brittleness, which causes HSC structures to fail explosively if the concrete confinement is not adequate. The traditional method of installing transverse steel as confinement is not feasible in HSC structures, as the steel will be too congested to ensure proper concrete placing. To overcome the problem, double-skinned high-strength concrete-filled-steel-tubular (HSCFST) columns has been advocated, which could provide large, continuous and uniform confinement to HSC. However, a major shortcoming of the double-skinned HSCFST columns is the imperfect interface bonding that occurs at the elastic stage that reduces the elastic strength and stiffness of columns. To improve the situation, the authors have verified previously that using external steel rings on the outer steel tube can successfully restrict the dilation of HSCFST columns and thus restore an intact interface bonding condition. As a continued study, the authors will in this paper develop a theoretical model for predicting the uni-axial load-carrying capacity of doubled-skinned HSCFST columns.

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13

Tao, Zhong, and Lin-Hai Han. "Behaviour of concrete-filled double skin rectangular steel tubular beam–columns." Journal of Constructional Steel Research 62, no. 7 (July 2006): 631–46. http://dx.doi.org/10.1016/j.jcsr.2005.11.008.

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14

Shekastehband, B., A. Taromi, and K. Abedi. "Fire performance of stiffened concrete filled double skin steel tubular columns." Fire Safety Journal 88 (March 2017): 13–25. http://dx.doi.org/10.1016/j.firesaf.2016.12.009.

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15

Wang, Yan Ze, and Bai Shou Li. "Axial Behavior of Concrete-Filled Double Skin Steel Tubular Stub Columns Filled with Demolished Concrete Lump." Advanced Materials Research 898 (February 2014): 407–10. http://dx.doi.org/10.4028/www.scientific.net/amr.898.407.

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To analyze the axial compression bearing capacity of concrete filled double skin steel tubular (CFDST) stub columns which are filled with demolished concrete lump, twelve stub columns are tested. The main experimental parameters were the diameter-to-thickness ratio, mixing ratio and hollow section ration.Load-displacement curves and failure mode were analyzed, the compressive capacity determined from related design rules were compared with the peak load obtained in the tests. All specimens have a good performance of ductility and late bearing capacity. When the width-thickness is 72 and have a same mixing ratio, CFDST have the same bearing capacity with CFT. When the mixing ratio is 0 and width-thickness is 120, the bearing capacity of CFDST increase 16% than CFT. When the new concrete have similar compressive strength with old and mixing ratio is 25%, the bearing capacity of CFDST increase 18.8% than CFT.

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16

Wang, Yan Ze, and Bai Shou Li. "Axial Behavior of Concrete-Filled Double Skin Steel Tubular Stub Columns Filled with Demolished Concrete Lump." Applied Mechanics and Materials 556-562 (May 2014): 671–74. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.671.

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To analyze the axial compression bearing capacity of concrete filled double skin steel tubular (CFDST) stub columns which are filled with demolished concrete lump, twelve stub columns are tested. The main experimental parameters were the diameter-to-thickness ratio, mixing ratio and hollow section ration.Load-displacement curves and failure mode were analyzed, the compressive capacity determined from related design rules were compared with the peak load obtained in the tests. All specimens have a good performance of ductility and late bearing capacity. When the width-thickness is 72 and have a same mixing ratio, CFDST have the same bearing capacity with CFT. When the mixing ratio is 0 and width-thickness is 120, the bearing capacity of CFDST increase 16% than CFT. When the new concrete have similar compressive strength with old and mixing ratio is 25%, the bearing capacity of CFDST increase 18.8% than CFT.

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17

Ci, Junchang, Mizan Ahmed, Hong Jia, Shicai Chen, Daxing Zhou, and Liqun Hou. "Experimental and numerical investigations of square concrete-filled double steel tubular stub columns." Advances in Structural Engineering 24, no. 11 (March 22, 2021): 2441–56. http://dx.doi.org/10.1177/13694332211004111.

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In this paper, the structural behavior of concrete-filled double steel tubular (CFDST) stub columns composed of square hollow sections is investigated experimentally and numerically. The experimental program comprises compression tests on short columns loaded concentrically. The test parameters mainly focused on the influences of the width-to-thickness ratios of steel tubes and concrete strength on the axial behavior of CFDST stub columns. Finite element (FE) models are also developed to investigate the influences of a wide range of structural parameters on their axial performance. It is observed that square CFDST columns have improved strength and ductility compared to their CFST and DCFST counterparts. Finally, a calculation formula is proposed to predict their ultimate compressive strengths under the axial compression load.

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18

Chen, Zhilin, Jun Wang, Jiye Chen, Hota GangaRao, Ruifeng Liang, and Weiqing Liu. "Responses of concrete-filled FRP tubular and concrete-filled FRP-steel double skin tubular columns under horizontal impact." Thin-Walled Structures 155 (October 2020): 106941. http://dx.doi.org/10.1016/j.tws.2020.106941.

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19

Ozbakkaloglu, Togay. "Reflections on Mechanisms Affecting the Behavior of FRP-Concrete-Steel Double-Skin Tubular Columns." Key Engineering Materials 705 (August 2016): 323–31. http://dx.doi.org/10.4028/www.scientific.net/kem.705.323.

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This paper presents the results of 20 hollow and concrete-filled double-skin tubular columns (DSTCs), which were tested as part of a comprehensive experimental program that was undertaken at The University of Adelaide on FRP-concrete steel DSTCs. The paper is aimed at providing important insights into the influence of two key parameters, namely the diameter of inner steel tube and presence/absence of a concrete-filling inside the inner steel tube, which play major roles in the column behavior through their influences on a series of interacting mechanisms that govern the complex system behavior. A detailed examination of the results yielded a number of important insights into the mechanisms that influence the compressive behavior of DSTCs.

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20

Ahmed, Mizan, Qing Quan Liang, and Ahmed Hamoda. "Fiber element modeling of circular double-skin concrete-filled stainless-carbon steel tubular columns under axial load and bending." Advances in Structural Engineering 25, no. 5 (January 10, 2022): 1114–35. http://dx.doi.org/10.1177/13694332211065187.

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Circular concrete-filled double-skin steel tubular (CFDST) columns with external stainless-steel are high-performance composite columns that have potential applications in civil construction including the construction of offshore structures, bridge piers, and transmission towers. Reflecting the limited research performed on investigating their mechanical performance, this study develops a computationally efficient fiber model to simulate the responses of short and slender beam-columns accounting for the influences of material and geometric nonlinearities. Accurate material laws of stainless steel, carbon steel, and confined concrete are implemented in the mathematical modeling scheme developed. A new solution algorithm based on the Regula-Falsi method is developed to maintain the equilibrium condition. The independent test results of short and slender CFDST beam-column are utilized to validate the accuracy of the theoretical solutions. The influences of various column parameters are studied on the load-axial strain [Formula: see text] curves, load-lateral deflection [Formula: see text] curves, column strength curves, and interaction curves of CFDST columns. Design formulas are suggested for designing short and beam-columns and validated against the numerical results. The computational model is found to be capable of simulating the responses of CFDST short and slender columns reasonably well. Parametric studies show that the consideration of the concrete confinement is important for the accuracy of the prediction of their mechanical responses. Furthermore, high-strength concrete can be utilized to enhance their load-carrying capacity particularly for short and intermediate slender beam-columns. The strengths of CFDST columns computed by the suggested design model are in good agreement with the test and numerical results.

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21

Muhammad, Naseem Baig, Jian Sheng Fan, and Jian Guo Nie. "Effects of Hollowness on Strength of Double Skinned Concrete Filled Steel Tubular Columns of Different Geometries under Axial Loading." Applied Mechanics and Materials 94-96 (September 2011): 1746–51. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.1746.

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Concrete filled tubular columns (CFT) have been used in buildings and bridges since long in history, and research reported in china is since 1970s. It has become popular as structural members due to their excellent structural performance characteristics, which include high strength, stiffness and high ductility. In modern building construction, steel rectangular hollow sections (RHS), square hollow sections (SHS) and circular hollow sections (CHS) are often filled with concrete to form a composite column. Such composite columns are well recognized in view of their high load carrying capacity, fast construction, small cross section, and high fire resistance. Compared to concrete-filled steel tubular (CFT) columns, the DSCFT can reduce its own weight while have a high flexural stiffness. Compared to traditional RC bridge columns and CFT columns it has high bending stiffness, avoids instability under external pressure, is light weight, possesses good damping characteristics due to increase in section modulus. In present study it is found that there is a definite increase in strength. Circular columns had all the properties better than other geometric shapes; strength increase was almost 20 % as compared to square columns. It is expected that if same ratios are maintained at projected scale, there would be a definite increase in strength and behavior of the columns. New concept of hollowness introduced is valid for all geometric shapes in DSCFTs and gives fairly good idea about its limits and effects on strength of columns. The equations given in different design codes give conservative values and hence need to be revised for DSCFTs both for seismic and normal designs.

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22

Zhang, Bing, Jun-Liang Zhao, Tao Huang, Ning-Yuan Zhang, Yi-Jie Zhang, and Xia-Min Hu. "Effect of fiber angles on hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns under monotonic axial compression." Advances in Structural Engineering 23, no. 7 (January 2, 2020): 1487–504. http://dx.doi.org/10.1177/1369433219895916.

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Hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns are a novel form of hollow columns that combine two traditional construction materials (i.e. concrete and steel) with fiber-reinforced polymer composites. Hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns consist of an inner tube made of steel, an outer tube made of fiber-reinforced polymer, and a concrete layer between the two tubes. Existing studies, however, are focused on hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns with fibers of the fiber-reinforced polymer tube oriented in the hoop direction or close to the hoop direction. In order to investigate the effect of fiber angles (i.e. the fiber angle between the fiber orientation and the longitudinal axis of the fiber-reinforced polymer tube), monotonic axial compression tests were conducted on hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns with an fiber-reinforced polymer tube of ±45°, ±60°, or ±80° fiber angles. There were two types of steel tubes adopted for these hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns. The fiber-reinforced polymer tube thickness was also investigated as an important parameter. Experimental results showed that the confinement effect of the fiber-reinforced polymer tube increased with the increase of the absolute value of fiber angles, whereas the ultimate axial strain of hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns decreased with the increase of the absolute value of fiber angles. An existing stress–strain model, which was developed on the basis of hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns with an fiber-reinforced polymer tube of ±90° fiber angles, is verified using the test results of this study. For the compressive strength of the confined concrete in hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns, the existing model provides conservative predictions for specimens with a ±80° fiber-reinforced polymer tube, overestimated predictions for specimens with a ±60° fiber-reinforced polymer tube, and close predictions for specimens with a ±45° fiber-reinforced polymer tube.

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23

Hsiao, Po-Chien, K. Kazuhiro Hayashi, Ryousuke Nishi, Xu-Chuan Lin, and Masayoshi Nakashima. "Investigation of Concrete-Filled Double-Skin Steel Tubular Columns with Ultrahigh-Strength Steel." Journal of Structural Engineering 141, no. 7 (July 2015): 04014166. http://dx.doi.org/10.1061/(asce)st.1943-541x.0001126.

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24

Louk Fanggi, Butje Alfonsius, and Togay Ozbakkaloglu. "Effect of Loading Pattern on Performance of FRP-HSC-Steel Double Skin Tubular Columns." Advanced Materials Research 919-921 (April 2014): 83–87. http://dx.doi.org/10.4028/www.scientific.net/amr.919-921.83.

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This paper reports on part of an ongoing experimental program at the University of Adelaide on FRP-concrete-steel double-skin tubular columns (DSTCs). The main emphasis of the study reported in this paper was to investigate the influence of loading pattern on the axial compressive behavior of DSTCs. To this end, 12 hollow and concrete-filled DSTCs were manufactured and tested under monotonic or cyclic axial compression. All of the specimens were manufactured using high-strength concrete (HSC). The results of the experimental study indicate that that concrete in cyclically loaded hollow DSTCs exhibits slightly larger strength and strain enhancement ratios than concrete in companion monotonically loaded DSTCs. The results also indicate that concrete in filled DSTCs exhibit slightly larger strength enhancement ratios than and similar strain enhancement ratios to concrete in monotonically loaded DSTCs.

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25

Zhou, Feng, Yingfei Li, and Baiping Dong. "Experimental investigation of concrete-filled double-skin stainless steel tubular beam-columns." Journal of Constructional Steel Research 196 (September 2022): 107406. http://dx.doi.org/10.1016/j.jcsr.2022.107406.

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26

Mahdi Saleh, Samoel, and Fareed Hameed Majeed. "Experimental Behavior of High Strength Concrete Filled Double Skin Steel Tubular Columns." Iraqi Journal of Civil Engineering 12, no. 1 (June 1, 2018): 75–85. http://dx.doi.org/10.37650/ijce.2018.142410.

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27

Wang, Yan Ze, and Bai Shou Li. "Finite Element Analysis for Concrete Filled Double-Skin Steel Tubular Stub Columns." Advanced Materials Research 690-693 (May 2013): 696–99. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.696.

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To realize axial load behavior of CFDST, ANSYS is used to analyze the process from load to destruction that hollow section ratio is the main variable parameter. To explore the validity of finite element analysis software, axial compressive strength is calculated combined with formulas of existing criterions. The results show the finite element results have a good agreement with text values and calculation.

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28

Deng, Ran, Xu-Hong Zhou, Xiao-Wei Deng, Ke Ke, Jiu-Lin Bai, and Yu-Hang Wang. "Compressive behaviour of tapered concrete-filled double skin steel tubular stub columns." Journal of Constructional Steel Research 184 (September 2021): 106771. http://dx.doi.org/10.1016/j.jcsr.2021.106771.

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29

Hasan, Hussein Ghanim, and Talha Ekmekyapar. "Bond-slip behaviour of concrete filled double skin steel tubular (CFDST) columns." Marine Structures 79 (September 2021): 103061. http://dx.doi.org/10.1016/j.marstruc.2021.103061.

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30

Li, Wei, Qing-Xin Ren, Lin-Hai Han, and Xiao-Ling Zhao. "Behaviour of tapered concrete-filled double skin steel tubular (CFDST) stub columns." Thin-Walled Structures 57 (August 2012): 37–48. http://dx.doi.org/10.1016/j.tws.2012.03.019.

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31

Guo, Zhan, Yu Chen, Yao Wang, and Minyang Jiang. "Experimental study on square concrete-filled double skin steel tubular short columns." Thin-Walled Structures 156 (November 2020): 107017. http://dx.doi.org/10.1016/j.tws.2020.107017.

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32

U. M., Sulthana, and Jayachandran S. A. "Axial Compression Behaviour of Long Concrete Filled Double Skinned Steel Tubular Columns." Structures 9 (February 2017): 157–64. http://dx.doi.org/10.1016/j.istruc.2016.12.002.

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33

Yao, Yao, Mengjia Liu, and Hongcun Guo. "Concrete filled double skin steel tubular columns subjected to non-uniform heating." Journal of Constructional Steel Research 158 (July 2019): 263–78. http://dx.doi.org/10.1016/j.jcsr.2019.03.035.

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34

Huang, Hong, Lin-Hai Han, Zhong Tao, and Xiao-Ling Zhao. "Analytical behaviour of concrete-filled double skin steel tubular (CFDST) stub columns." Journal of Constructional Steel Research 66, no. 4 (April 2010): 542–55. http://dx.doi.org/10.1016/j.jcsr.2009.09.014.

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35

Mohd Zuki, S. S., J. Jayaprakash, Shahiron Shahidan, and Ong Chong Yong. "Behavior of Fire Exposed Concrete-Filled Double Skin Steel Tubular (CFDST) Columns under Concentric Axial Loads." Applied Mechanics and Materials 773-774 (July 2015): 938–42. http://dx.doi.org/10.4028/www.scientific.net/amm.773-774.938.

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This paper presents the result of an experimental investigation of axial behavior of concrete-filled double skin steel tubular (CFDST) columns exposed to high temperature under the action of monotonically applied concentric axial loads. The columns were exposed to ASTM E-119 standard fire curve until 600°C and kept constant for two different exposure time (i.e., 60 and 90 minutes). Failure patterns and reduction in strength, ductility and stiffness of CFDST columns are reported. Factors influencing the strength, ductility and stiffness of CFDST columns during fire exposure, i.e., exposure time, temperature of concrete core and temperature of inner steel tube, are also discussed.

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36

Huang, Youqin, Jiyang Fu, Di Wu, Airong Liu, Wei Gao, and Yonglin Pi. "Dynamic Stability of Slender Concrete-Filled Steel Tubular Columns with General Supports." International Journal of Structural Stability and Dynamics 19, no. 04 (April 2019): 1950045. http://dx.doi.org/10.1142/s0219455419500457.

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The static stability of slender concrete-filled steel tubular (CFST) columns has been explored thoroughly while few researches have been carried out on the dynamic stability of CFST columns even if all applied loadings are naturally time-dependent. This paper presents an analytical procedure for evaluating the dynamic stability of CFST columns of various composite cross-sections under general boundary conditions. This paper is featured by the following facts: (1) proportional damping is considered in derivation of the governing equations on the lateral parametric vibration of the CFST columns subject to axial excitation; (2) Bolotin’s method is used to determine the boundaries of the regions of dynamic instability for the CFST columns with general supports; (3) the relationship of static and dynamic stability, and the effects of boundary conditions and cross-sectional forms are uncovered. New findings of this investigation are (1) larger amplitude or constant component of excitation make it easier for the dynamic instabilities of the CFST columns to occur, while increasing the constant component of excitation reduces the critical value of frequency ratio for the dynamic instability to occur; (2) the dynamic stability analysis can determine the critical loads for both the static and dynamic instability of CFST columns, and the critical instability load decreases with increasing disturbance on the static load; (3) under the same consumptions of steel and concrete, the square columns have better performance of dynamic stability than the circular columns, but there is no definite conclusion on the effect of hollow size on the dynamic stability of double-skin columns.

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37

Ayough, Pouria, Zainah Ibrahim, N. H. Ramli Sulong, Po-Chien Hsiao, and Mohamed Elchalakani. "Numerical analysis of square concrete-filled double skin steel tubular columns with rubberized concrete." Structures 32 (August 2021): 1026–47. http://dx.doi.org/10.1016/j.istruc.2021.03.054.

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38

Youssf, Osama, Reza Hassanli, Julie E. Mills, and Yan Zhuge. "Axial Compression Behaviour of Hybrid Double-Skin Tubular Columns Filled with Rubcrete." Journal of Composites Science 3, no. 2 (June 19, 2019): 62. http://dx.doi.org/10.3390/jcs3020062.

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Double-skin tubular columns (DSTCs) have become a competitive candidate for column members due to their important advantages compared with conventional reinforced concrete columns, including their better weight-to-strength ratio and ease of construction. Using Rubcrete in hybrid DSTCs is of great interest due to the potential of this system to overcome the Rubcrete material deficiencies and to add more ductility, toughness, seismic resistance, confinement effectiveness, and environmentally-friendly features to that structural system compared to conventional concrete. In this paper, hybrid DSTCs made out of Rubcrete, sandwiched between a fibre reinforced polymer (FRP) tube and a steel tube, were tested. The examined variables were concrete sand or stone replacement ratio (0% and 20%), FRP wall thickness (1- and 2-layers), steel wall thickness (3.2 mm and 4.5 mm), void ratio (50% and 76%), and void shape (circular or square). The axial and lateral stress–strain responses were monitored, measured, and compared. According to this investigation, using Rubcrete in hybrid DSTCs can enhance the axial and hoop strain capacities, especially with fine rubber particles. It was also observed that the adverse influence of using rubber on column ultimate capacity was much lower in DSTC specimens, compared with that of unconfined Rubcrete columns. Therefore, using Rubcrete with fine rubber particles is recommended in DSTC structural columns.

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39

Wang, Jian, Junwu Xia, Hongfei Chang, Youmin Han, Linli Yu, and Li Jiang. "Experimental Study on Axial Compressive Behavior of Gangue Aggregate Concrete Filled FRP and Thin-Walled Steel Double Tubular Columns." Coatings 11, no. 11 (November 18, 2021): 1404. http://dx.doi.org/10.3390/coatings11111404.

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In the present paper, the monotonic axial compression test of gangue aggregate concrete filled Fiber reinforced polymer (FRP) and thin-walled steel double tubular columns (DTCC) was carried out, and the gangue aggregate concrete filled FRP tubular columns (CFFT) were designed as a comparison. The main experimental factors were the confinement level of the FRP jacket, the relative diameter ratio (the ratio of the outer diameter of the steel tube to the inner diameter of the FRP jacket), and the different strengths of gangue aggregate concrete. The test results show that the bearing capacity and ductility of gangue aggregate concrete in CFFT were significantly improved. As the local buckling of thin-walled steel tube was effectively inhibited, the load bearing capacity of DTCC was further improved compared with CFFT, but the change of dilation behavior and ductility was insignificant. By analyzing the bi-directional stress state of the steel tube, the confinement level of the external FRP jacket was the most sensitive factor affecting the hoop stress of the steel tube, and the axial stress was obviously weakened under the bi-directional stress state. In addition, with the increase of steel tube diameter, the confinement effect of steel tube in DTCC became more obvious.

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40

Balasubramani, Natesan, and R. Thenmozhi. "Behaviour and Strength of Innovative Steel Concrete Columns with SCC." Advanced Materials Research 984-985 (July 2014): 684–92. http://dx.doi.org/10.4028/www.scientific.net/amr.984-985.684.

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In this paper, totally 7 innovative steel concrete composite columns were investigated for axial load and reported. 6 of them were modified DSHCFT columns consisting only outer skin tube and butting concrete and the remaining one was Double Skinned Hollow Concrete Filled steel Tubular columns having outer and inner steel tube (DSHCFT), which was annularly in-filled with Self-Compacting Concrete (SCC). The concrete grade and yield strength of steel tubes used were respectively M35 and 250MPa. The ratios of outer tube diameter to its thickness were 34 to 36. The length to outer diameter (aspect ratio) and the hollowness ratio were from 2.4 to 4.5 and from 0.35 to 0.5 respectively. Mechanical behaviour in term of stiffness, confinement, ultimate strength and ductility were discussed. Load Vs mid-span deflection diagrams, failure patterns of the specimens are presented. The existence of composite action between steel and concrete and confinement of concrete were experimentally evidenced. Suitability of two existing design codes is verified. For the design of the modified DSHCFT Stub columns with SCC and DSHCFTs, a possible simplified formula is suggested.Keywords: Failure mode, Stiffness, ductility, confinement, Ultimate load, Simplified formula.

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41

Zhang, Dongfang, Junhai Zhao, and Shuanhai He. "Cyclic Testing of Concrete-Filled Double-Skin Steel Tubular Column to Steel Beam Joint with RC Slab." Advances in Civil Engineering 2018 (July 26, 2018): 1–15. http://dx.doi.org/10.1155/2018/7126393.

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The design of composite joints for connecting concrete-filled double-skin tubular (CFDST) columns to steel beams supporting reinforced concrete (RC) slabs is presented in this paper. Five half-scale specimens were designed, including four composite joints with RC slab and one bare steel beam joint, and were tested under a constant axially compressive force and lateral cyclic loading at the top end of the column to evaluate their seismic behavior. The main experimental parameters were the construction of the joint and the type of the column. The seismic behaviors, including the failure modes, hysteresis curves, ductility, strength and stiffness degradation, and energy dissipation, were investigated. The failure modes of the composite joints depended on the joint construction and on the stiffness ratio of beams to columns. Joints of stiffening type had significantly higher load-bearing and deformation capacities than joints of nonstiffening type. Compared with the bare steel beam joint, the bearing capacities of the composite joints with RC slabs were markedly increased. The composite action was remarkable under sagging moments, resulting in larger deformation on the bottom flanges of the beams. Overall, most specimens exhibited full hysteresis loops, and the equivalent viscous damping coefficients were 0.282∼0.311. The interstory drift ratios satisfied the requirements specified by technical regulations. Composite connections of this type exhibit excellent ductility and favorable energy dissipation and can be effectively utilized in superhigh-rise buildings erected in earthquake zones.

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42

Zhou, Rong, Jun Hai Zhao, and Xue Ying Wei. "Research on Bearing Capacity of Concrete Filled Double Skin (CHS Inner and SHS Outer) under Eccentric Compression." Applied Mechanics and Materials 723 (January 2015): 422–26. http://dx.doi.org/10.4028/www.scientific.net/amm.723.422.

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The ultimate load calculation formula for the solid multi barrel tube-confined concrete columns (CHS inner and SHS outer) was derived based on the Unified Strength Theory (UST) in this paper. The influence of intermediate principal stress and the double restriction effect and the decrease of longitudinal stress were considered in the formula. Based on the axial compression load and consider the eccentricity ratio and slenderness ratio, by introducing the reduction factor of concrete strength and the equivalent restriction reduction factor, based on unified strength theory solutions of thick tube, combined with concrete filled skin tube unified theory, deduce the calculation formula of eccentric compression bearing capacity of concrete filled steel tubular columns and analysis the influence complication.

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43

Li, Jingzhe, Qihan Shen, Jingfeng Wang, Beibei Li, and Guoqiang Li. "Axial Compression Test and Numerical Investigation of Concrete-Filled Double-Skin Elliptical Tubular Short Columns." Buildings 12, no. 12 (December 2, 2022): 2120. http://dx.doi.org/10.3390/buildings12122120.

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To probe into the performance of concrete-filled double-skin elliptical steel tubular (CFDEST) members, this paper designs and conducts an experiment on CFDEST short columns imposed with axial pressure, and finite element (FE) models of the axially compressed CFDEST stub columns are established and verified by the test outcomes, taking the influences of elliptical cross-section and hollow ratio into account. The impressions of various parameters, such as hollow ratio, diameter-to-thickness ratio, aspect ratio and so on, on the load-bearing capacity, initial rigidity and ductility property were investigated systematically. Moreover, the typical failure modes, contact pressure and concrete longitudinal stress of the axially compressed CFDEST short column are revealed. In light of the findings acquired by the laboratory tests and numerical analyses, the calculation formulae for evaluating the axial compress capacity of the CFDEST short column are proposed by taking the impact of the sectional aspect ratio and hollow ratio into account. The results indicate that the failure morphologies of axially compressed CFDEST short columns mainly include outward local bulges of the outside EST, the inward bulges of the inside EST and the crushing of core concrete. The axial compress capacity of the CFDEST short column would increase with the decrease in the sectional hollow ratio and aspect ratio. The calculation method is proved to be an accurate and reliable approach to evaluate the axial compress capacity of the CFDEST short column.

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44

Louk Fanggi, Butje Alfonsius, and Togay Ozbakkaloglu. "Relative Performance of FRP-Concrete-Steel Double Skin Tubular Columns versus Solid and Hollow Concrete-Filled FRP Tubes." Applied Mechanics and Materials 501-504 (January 2014): 3–7. http://dx.doi.org/10.4028/www.scientific.net/amm.501-504.3.

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This paper reports on part of an ongoing experimental program at the University of Adelaide on FRP-concrete-steel composite columns. The results from twenty specimens including 12 double skin tubular columns (DSTCs), two solid concrete-filled fiber reinforced polymer (FRP) tubes (CFFTs), and six CFFTs with inner voids (H-CFFTs) are presented. The specimens were manufactured using high-strength concrete (HSC) and their FRP tubes were fabricated using unidirectional S-glass fiber sheets. The results of the experimental study indicate that that H-CFFTs perform significantly worse than DSTCs and CFFTs and their performance further degrades with an increase in the diameter of inner void. Comparison of the results from DSTC and CFFT specimens indicate that both hollow and concrete-filled DSTCs exhibit improved compressive behavior compared to CFFTs.

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45

Deng, Ran, Xu-Hong Zhou, Yu-Hang Wang, Jiu-Lin Bai, and Xiao-Wei Deng. "Experimental study on Tapered Concrete-Filled Double Skin Steel Tubular columns under torsion." Thin-Walled Structures 177 (August 2022): 109444. http://dx.doi.org/10.1016/j.tws.2022.109444.

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46

Han, Lin-Hai, Zhong Tao, Hong Huang, and Xiao-Ling Zhao. "Concrete-filled double skin (SHS outer and CHS inner) steel tubular beam-columns." Thin-Walled Structures 42, no. 9 (September 2004): 1329–55. http://dx.doi.org/10.1016/j.tws.2004.03.017.

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47

Han, Lin-Hai, Hong Huang, Zhong Tao, and Xiao-Ling Zhao. "Concrete-filled double skin steel tubular (CFDST) beam–columns subjected to cyclic bending." Engineering Structures 28, no. 12 (October 2006): 1698–714. http://dx.doi.org/10.1016/j.engstruct.2006.03.004.

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48

Lu, Hui, Lin-Hai Han, and Xiao-Ling Zhao. "Fire performance of self-consolidating concrete filled double skin steel tubular columns: Experiments." Fire Safety Journal 45, no. 2 (February 2010): 106–15. http://dx.doi.org/10.1016/j.firesaf.2009.12.001.

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49

Ahmed, Mizan, Qing Quan Liang, Vipulkumar Ishvarbhai Patel, and Muhammad N. S. Hadi. "Behavior of eccentrically loaded double circular steel tubular short columns filled with concrete." Engineering Structures 201 (December 2019): 109790. http://dx.doi.org/10.1016/j.engstruct.2019.109790.

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50

Deng, Jun, Yifeng Zheng, Yi Wang, Tonghua Liu, and Hui Li. "Study on Axial Compressive Capacity of FRP-Confined Concrete-Filled Steel Tubes and Its Comparisons with Other Composite Structural Systems." International Journal of Polymer Science 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/6272754.

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Concrete-filled steel tubular (CFST) columns have been widely used for constructions in recent decades because of their high axial strength. In CFSTs, however, steel tubes are susceptible to degradation due to corrosion, which results in the decrease of axial strength of CFSTs. To further improve the axial strength of CFST columns, carbon fiber reinforced polymer (CFRP) sheets and basalt fiber reinforced polymer (BFRP) sheets are applied to warp the CFSTs. This paper presents an experimental study on the axial compressive capacity of CFRP-confined CFSTs and BFRP-confined CFSTs, which verified the analytical model with considering the effect of concrete self-stressing. CFSTs wrapped with FRP exhibited a higher ductile behavior. Wrapping with CFRP and BFRP improves the axial compressive capacity of CFSTs by 61.4% and 17.7%, respectively. Compared with the previous composite structural systems of concrete-filled FRP tubes (CFFTs) and double-skin tubular columns (DSTCs), FRP-confined CFSTs were convenient in reinforcing existing structures because of softness of the FRP sheets. Moreover, axial compressive capacity of CFSTs wrapped with CFRP sheets was higher than CFFTs and DSTCs, while the compressive strength of DSTCs was higher than the retrofitted CFSTs.

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