Estimation of axial load-carrying capacity of concrete-filled steel tubes using surrogate models

2020 ◽  
Author(s):  
Hai-Bang Ly ◽  
Binh Thai Pham ◽  
Lu Minh Le ◽  
Tien-Thinh Le ◽  
Vuong Minh Le ◽  
...  
Keyword(s):  
Carrying Capacity ◽  
Axial Load ◽  
Surrogate Models ◽  
Load Carrying Capacity ◽  
Steel Tubes ◽  
Load Carrying ◽  
Concrete Filled Steel Tubes

scholarly journals A Detailed Experimental Study on The Flexural Behaviour of Concrete Filled Steel Tube Beams

2018 ◽  
pp. 196-203
Author(s):  
Shaik Heena ◽  
Syed Rizwan ◽  
A.B.S. Dadapeer
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Steel Tube ◽  
Deformation Capacity ◽  
Load Carrying Capacity ◽  
Shear Connector ◽  
Steel Tubes ◽  
Load Carrying ◽  
Concrete Filled Steel Tubes

Concrete filled steel tubes (CFST) member have many advantages compared with the ordinary structural member made of steel or reinforced concrete. One of the main advantages is the interaction between the steel tube and concrete. Concrete delays the steel tube’s local buckling, whereas the steel tube confines the concrete and thereby increases the concrete’s strength. CFSTs are economical and permit rapid construction because the steel tube serves as formwork and reinforcement to the concrete fill, negating the need for either. The deformation capacity of the system is increased by the combined action of the concrete fill with the thin, ductile steel tube. The concrete fill significantly increases inelastic deformation capacity and the compressive stiffness and load capacity of the CFST member. In building construction concrete filled steel tubes are very widely used for columns in combination with steel or reinforced concrete beam. In this work totally 9 specimens were tested out of which 3 specimens were empty steel tubes and remaining 6 specimens were concrete filled with different bonding techniques. As it is prefabricated time consumption will be less in construction practice and due to confinement more ductility is expected which is very useful in earthquake resistant structures. Load carrying capacity of CFST almost doubled in comparison with empty steel tubes. Ultimate load carrying capacity of concrete filled steel tube beams almost doubled compared to empty steel tubes. Compared to empty steel tubes, strength increase of 67.19%, 97.48% and 114.84% was observed in normal CFST, CFST with sand blasting and CFST with diagonal shear connector beams respectively. Average ultimate load of EST was 105.66kN whereas average load of CFSTB, CFSTBWSB and CFSTBWDSC was 176.66, 208.66 and 227kN respectively. The maximum load was taken by the specimen CFSTBWDSC – 03 which was 231kN, it may be because of presence of diagonal shear connector inside the tube.

The effect of different retrofitting techniques on the axial load carrying capacity of damaged cylindrical shells

Structures ◽  
2021 ◽  
Vol 31 ◽  
pp. 590-601
Author(s):  
Hamed Rahman Shokrgozar ◽  
Vahid Akrami ◽  
Tayebeh Jafari Ma'af ◽  
Naseraldin Shahbazi
Keyword(s):  
Carrying Capacity ◽  
Axial Load ◽  
Cylindrical Shells ◽  
Load Carrying Capacity ◽  
Load Carrying

Experimental Investigation on Composite Circular Steel Columns - Taguchi’s Approach

2011 ◽  
Vol 105-107 ◽  
pp. 1742-1750
Author(s):  
N. S. Kumar ◽  
Sameera Simha T.P.
Keyword(s):  
Linear Regression ◽  
Carrying Capacity ◽  
Orthogonal Array ◽  
Regression Models ◽  
Ultimate Load ◽  
Steel Tube ◽  
Load Carrying Capacity ◽  
Taguchi’S Method ◽  
Steel Tubes ◽  
Load Carrying

Composite circular steel tubes- with and without epoxy infill for three different grades of concrete are tested for ultimate load capacity and axial shortening , under axial monotonic loading for compression. Steel tubes are compared for different lengths, cross sections and thickness. Specimens were tested separately after adopting Taguchi’s L9 (Latin Squares) Orthogonal array in order to save the initial experimental cost on number of specimens and experimental duration. DOE (Design of Experiment) approach was adopted. Results were generated using Taguchi’s method-a new technique to get mean effects plot. Analysis was carried out using ANOVA (Analysis of Variance) technique with the assistance of Mini Tab v15- a statistical soft tool. Results were verified after conducting preliminary nine combination experiments as per L9 orthogonal array and linear regression models were developed. Comparison for predicted and experimental output is obtained from linear regression plots. To know the implications of different factors on circular composite columns with and without epoxy, surface contours were also generated. From this research study it is concluded that ,Regression models which were developed with minimum number of experiments based on Taguchi’s method predicted the axial load carrying capacity very well and reasonably well for at ultimate point. Cross sectional area of steel tube has most significant effect on ultimate load carrying capacity. Also it is observed that, as length of steel tube increased- load carrying capacity decreased.

Experiment Study on Influence of Initial Stress in Concrete Filled Steel Tubular Latticed Columns under Axial Load

2014 ◽  
Vol 518 ◽  
pp. 170-177
Author(s):  
Fu Yun Huang ◽  
Guan Yu ◽  
Bao Chun Chen ◽  
Jian Zhong Li
Keyword(s):  
Initial Stress ◽  
Carrying Capacity ◽  
Axial Load ◽  
Ultimate Load ◽  
Load Carrying Capacity ◽  
Experiment Study ◽  
Load Carrying ◽  
Plastic Phase ◽  
Cfst Columns ◽  
Ultimate Load Carrying Capacity

The testing of concrete filled steel tubular (CFST) latticed columns with initial stress had been conducted under axial load. The set-ups subjected to initial stress, the curves of load to deformation as well as the hooping effect were analyzed. The trial results indicate that the CFST columns with initial stress have smaller of combined stiffness and ultimate load-carrying capacity as compared with CFST columns without initial stress. Furthermore, the presence of initial stress will advance the coming of plastic phase, and contemporary, put off the appearances of hooping effect so that it cannot be sufficient exerted, which decrease the ultimate load-carrying capacity at all. Nevertheless, the mechanical behaviour of lacing tubes does not vary with the initial stress and all the lace tubes are stayed in the elastic phase during the testing.

scholarly journals Axial Load-carrying Capacity of Steel Tubed Concrete Short Columns Confined with Advanced FRP Composites

2020 ◽  
Author(s):  
Ali Raza ◽  
Syyed Adnan Raheel Shah ◽  
Mudasser Muneer Khan ◽  
Faraz ul Haq ◽  
Hunain Arshad ◽  
...  
Keyword(s):  
Finite Element ◽  
Compressive Strength ◽  
Finite Element Model ◽  
Carrying Capacity ◽  
Axial Load ◽  
Element Model ◽  
Confined Concrete ◽  
Superior Performance ◽  
Load Carrying Capacity ◽  
Load Carrying

Fiber Reinforced Polymers (FRPs) have wide applications in the field of concrete construction due to their superior performance over conventional materials. This research focuses on the structural behavior of steel tube FRP jacket–confined concrete (STFC) columns under axial concentric loading and proposes a new empirical equation for predicting the axial load-carrying capacity of STFC columns having thickness of FRP-fabric ranging from 0.09 mm to 5.9 mm. A large database of 700 FRP-confined concrete specimens is developed with the detailed information of critical parameters, i.e. elastic modulus of FRPs (Ef), compressive strength of unconfined concrete (fc’o), diameter of specimen (D), height of specimen (H), total thickness of FRPs (N.tf), and the ultimate strength of confined concrete (fc’c). After the preliminary evaluation of constructed database, a new empirical model is proposed for the prediction of axial compressive strength of FRP-confined specimens using general regression analysis by minimizing the error functions such as root mean squared error (RMSE) and coefficient of determination (R2). The proposed FRP-confinement strength model presented higher accuracy as compared with previously proposed models. Finally, an equation is proposed for the predictions of axial load carrying capacity of STFC columns. For the validation of proposed equation, an extensive parametric study is performed using the proposed nonlinear finite element model (FEM). The FEM is calibrated using the load-deflection results of STFC columns from literature. A close agreement was observed between the predictions of proposed finite element model and proposed capacity equation.

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