scholarly journals Research on Dynamic Response of Concrete-Filled Steel Tube Columns Confined with FRP under Blast Loading

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Jing Dong ◽  
Junhai Zhao ◽  
Dongfang Zhang ◽  
Yingping Li

Recently, a concrete-filled steel tube confined with fiber-reinforced polymer (FRP) has become a hot research issue as a new type of structure. These studies mainly focus on its static performance and seismic and impact behaviour, with little research on its blast resistance performance. In this study, the dynamic response of concrete-filled steel tube columns confined with FRP under blast loading was investigated. Numerical analysis was implemented using multimaterial ALE method in the finite element analysis program LS-DYNA. The proposed numerical model was validated by the SDOF result and available experimental data. And the effects of the number of FRP layers, concrete strength, and cross section were also discussed in detail based on the proposed numerical model. The results indicate that the constraints of FRP effectively enhance the blast resistance of the column, and the vulnerable parts mainly occur at the middle and two ends of the column. The blast resistance of the column can be enhanced by increasing the number of FRP layers or concrete strength. These results could provide a certain basis for blast resistance design of concrete-filled steel tubes confined with FRP.

2014 ◽  
Vol 488-489 ◽  
pp. 704-707
Author(s):  
Ying Wang ◽  
Miao Li ◽  
Jin Hua Xu ◽  
He Fan

Based on finite element analysis o f concrete filled steel tube beam-column joints under the single axial compression ratio and concrete strength, further research was done to analyze the seismic performance of concrete filled steel tube beam-column joints under different axial compression ratio and concrete strength. Beam-column joint which is connected by bolts with welding extended steel sheets at the beam root was analyzed. The results show that with the increase of axial compression ratio, strength and stiffness degradation of the joint accelerated gradually. Axial compression ratio at 0.3, 0.4 are appropriate values for joints specimen, load-displacement hysteresis curve of joint specimens is relatively plump and shows good seismic performance. Chance of concrete strength also had effect on seismic performance of joint specimen, but in contrast it is not so obviously.


2014 ◽  
Vol 525 ◽  
pp. 568-572
Author(s):  
Yang Feng Wu ◽  
Hong Mei Zhang

A new composite strengthening method that the CFST short column was strengthened with concrete filled steel tube was presented. Through the finite element analysis of five specimens with strengthening circular concrete filled steel tube columns and a specimen without strengthening circular concrete filled steel tube to explore the impact of the outer layer of concrete strength grade, external pipe wall thickness for the ultimate bearing capacity of concrete filled steel tube columns. The results show that with the increase of the outer pipe wall thickness, double concrete filled steel tube column yield strength and ultimate strength have increased. As the outer concrete strength grade increased as the specimen bearing capacity increased. When the concrete strength grade greater than C40, the improvement of concrete strength for specimen ultimate bearing capacity is not great.


2011 ◽  
Vol 311-313 ◽  
pp. 1889-1893
Author(s):  
Ya Wen Du ◽  
Hong Yu Lin

Finite element analysis on three trusses was carried out in order to study the performance of combined truss with steel tube and concrete filled steel tube. The first specimen was a RHS truss, the second one was a combined truss with steel tube and concrete filled steel tube, and the third one was a concrete-filled steel tube truss. The results show that the finite element model can reflect the static performance of combined truss and can carry out the affective parameters analysis, which can offer theory evidence for engineering application of combined truss. The damage of three trusses was all due to the joint failure and the failure mode was all punishing shearing failure, but the concrete filled changed by the failure place of joints. The bearing capacity of three trusses was controlled by the jionts and the strength and stiffness of jionts were increased by the concrete filled in the chord, therefore the bearing capacity of trusses was increased while the deformation of trusses was decreased. In combined truss with steel tube and concrete filled steel tube, the concrete-filled steel tube joints can improve the bearing capacity and the steel tube joint can satisfy the requirements of deformation, which have obvious advantages in the engineering application.


2021 ◽  
Vol 2101 (1) ◽  
pp. 012059
Author(s):  
Z J Yang ◽  
X Li ◽  
G C Li ◽  
S C Peng

Abstract Hollow concrete-filled steel tubular (CFST) member is mainly adopted in power transmission and transformation structures, but when it is used in the superstructure with complex stress, the hollow CFST member has a low bearing capacity and is prone to brittle failure. To improve the mechanical performance of hollow CFST members, a new type of reinforced hollow high strength concrete-filled square steel tube (RHCFSST) was proposed, and its axial compression performance was researched. 18 finite element analysis (FEA) models of axially loaded RHCFSST stub columns were established through FEA software ABAQUS. The whole stress process of composite columns was studied, and parametric studies were carried out to analyze the mechanical performance of the member. Parameters of the steel strength, steel ratio, deformed bar and sandwich concrete strength were varied. Based on the simulation results, the stress process of members can be divided into four stages: elastic stage, elastoplastic stage, descending stage and gentle stage. With the increase of steel strength, steel ratio, the strength of sandwich concrete and the addition of deformed bars, the ultimate bearing capacity of members also increases. Additionally, the increment of those parameters will improve the ductility of the member, except for the sandwich concrete strength.


2012 ◽  
Vol 594-597 ◽  
pp. 947-954 ◽  
Author(s):  
Zhen Yu Liu

To study the debonding of concrete filled steel tube (CFST), pulling and bending methods were used to test the normal bond strength. Based on the test result, debonding due to temperature change and shrinkage of core concrete in CFST was analyzed. The test and analysis result shows that the bending method is a better test method; the concrete strength has little influence on bond strength while the surface condition of steel has much influence on it. The bond strength of steel which is rust is greater than that of the steel with smooth surface. According to the analysis on the bending test result, the normal bond strength of 0.86MPa was got and the debonding of CFST arch was analyzed, the analysis result shows that debonding will easily happen under the action of temperature change and shrinkage of core concrete. The test methods and results can provide a reference for engineering applications.


2018 ◽  
Vol 9 (4) ◽  
pp. 525-553 ◽  
Author(s):  
Wanxiang Chen ◽  
Zixin Zhou ◽  
Huihui Zou ◽  
Zhikun Guo

An approximate approach is developed to estimate the residual carrying-capacities of fire and near-field blast-damaged reactive powder concrete-filled steel tube columns. The single-degree-of-freedom model is employed to calculate the initial deflections of fire-damaged reactive powder concrete-filled steel tube columns subjected to axial and blast-induced transverse loads, and then a modified formula including double coefficient is further proposed to predict the ultimate resistance. Then, a series of blast-resistance and load carrying-capacity tests on six large-scale reactive powder concrete-filled steel tube columns are conducted to validate the suitability of theoretical method presented in this article. Blast tests demonstrate that the blast-resistances of reactive powder concrete-filled steel tube columns are more sensitive to fire durations than to scale distances. In addition, it is indicated that ISO-834 standard fire exposures cause significant degradations of material properties and have remarkable effects on the residual carrying-capacities of reactive powder concrete-filled steel tube columns. No local bucking and burst could be observed in the residual carrying-capacity tests; also, there are no visible hinge-like deformations in the mid-span area, and the excellent fire-resistances and blast-resistances of reactive powder concrete-filled steel tube columns are experimentally verified. Analytical results show that the predicted axial load capacities of six reactive powder concrete-filled steel tube columns are in good agreement with experimental data. All damage indices of the test specimens are within 0.8, meaning only minor to severe damage is done to the reactive powder concrete-filled steel tube column during fire and blast attacks, which is consistent with the test results.


2011 ◽  
Vol 94-96 ◽  
pp. 220-224 ◽  
Author(s):  
Xi Guang Cui ◽  
Hai Dong Xu

Considering the strain rate then puts forward the modified uniaxial dynamic constitutive model related to strain rate in concrete-filled square steel tube and the modified calculation results match well with the experimental results. Based on the above conclusion, uniaxial compression performance finite element analysis with different strain rate among 10-5/s–10-3/s is completed, the results showed that strain rate can obviously change the dynamic performance of the concrete-filled square steel tube. Through the analysis of the influencing factors of the core concrete compressive strength, it is showed that with the increasing of the strain rate and the improving of concrete strength, the ultimate bearing capacity of concrete-filled square steel tube is higher and the ductility is reduced. With the increasing of stirrup ratio, ultimate bearing capacity is greater and the ductility is enhanced. With the sectional dimensions increasing, the ultimate bearing capacity is greater and the ductility is enhanced.


2013 ◽  
Vol 838-841 ◽  
pp. 428-431 ◽  
Author(s):  
Ying Wang ◽  
Miao Li ◽  
He Fan ◽  
Jin Hua Xu

Rational finite element models established by ABAQUS to analysis the mechanical properties of square steel tubular beam-column joints under low cyclic loading. The two beam-column joints are connected with bolts, one is with welding extended steel sheets at the beam root and the other has no welding extended steel sheets. The calculation and analysis results show that the new joint style using concrete filled steel tube structure both in beams and columns has advantage on the seismic performance. The load-displacement hysteresis curve of the beam end is plump without significant pinching and the joint specimens showed good ductility. The comparative analysis reveals that the joint with welding extended steel sheets at the beam root is more superior in the seismic performance respected to the joint without welding extended steel sheets.


2012 ◽  
Vol 428 ◽  
pp. 103-107
Author(s):  
Shui Xing Zhou ◽  
Lu Li ◽  
Yue Ma ◽  
Ling Jun Li

Based on the constitutive relationship model of general concrete filled steel tube, and combining with the results and theoretical analysis of several self-stress concrete filled steel tubular specimens, the constitutive relationship model of self-stress concrete filled steel tube was established by introducing an improvement coefficient of concrete strength related to self-stress level. The calculations of specimens’ bearing capacity with different sectional steel ratios, values of self-stress and concrete strengths were performed, which were in a good accordance with those of experimental values.


Sign in / Sign up

Export Citation Format

Share Document