A numerical model for considering the bond-slip effect in axially loaded circular concrete-filled tube columns

2018 ◽  
Vol 21 (12) ◽  
pp. 1923-1935 ◽  
Author(s):  
Ju-young Hwang ◽  
Hyo-Gyoung Kwak ◽  
Yangsu Kwon
Keyword(s):  
Numerical Model ◽  
Governing Equation ◽  
Steel Tube ◽  
Slip Effect ◽  
Bond Slip ◽  
Correlation Studies ◽  
Axially Loaded ◽  
Nodal Displacements ◽  
Final Steel ◽  
Force Equilibrium

This article introduces a numerical model that simulates the bond-slip behaviour in axially loaded circular concrete-filled tube columns without applying double nodes required in the use of the classical bond-link element. After calculating the nodal displacements of in-filled concrete, the deformation in the steel tube at each node has been found through the back-substitution technique from the first to the final steel element using a governing equation constructed on the basis of the force equilibrium and displacement compatibility at each node. Finally, correlation studies between analytical and experimental results are conducted to verify the efficiency and applicability of the introduced model.

scholarly journals FE analysis of circular CFT columns considering bond-slip effect: A numerical formulation

2018 ◽  
Vol 9 (2) ◽  
pp. 245-257 ◽  
Author(s):  
Ju-Young Hwang ◽  
Hyo-Gyoung Kwak
Keyword(s):  
Numerical Model ◽  
Nodal Point ◽  
Bending Moment ◽  
Steel Tube ◽  
Fe Analysis ◽  
Slip Effect ◽  
Bond Slip ◽  
Bond Zone ◽  
Numerical Formulation ◽  
Force Equilibrium

Abstract. In this paper, a numerical model for the analysis of bond-slip occurring in concrete filled steel tube (CFT) columns is introduced. Unlike the classical bond-link or bond-zone element using double nodes, the introduced model considers the bond-slip effect without taking double nodes by incorporation of the equivalent steel stiffness. Upon constructing the equations system on the basis of the force equilibrium and the compatibility condition at each nodal point, the deformations in a steel tube are determined, followed by evaluation of the bond-slip. Moreover, as a part of solving the equations system to evaluate the slip behavior, the mechanical properties for steel and bond-slip have been changed and updated through an iteration procedure. Finally, the validity of the introduced numerical model is verified by comparing the experimental data with the analytical results for CFT columns subjected to axial force and bending moment.

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.

Numerical calculation of crack width in prestressed concrete beams with bond-slip effect

2019 ◽  
Vol 15 (2) ◽  
pp. 523-536
Author(s):  
Jinliang Liu ◽  
Yanmin Jia ◽  
Guanhua Zhang ◽  
Jiawei Wang
Keyword(s):  
Numerical Calculation ◽  
Numerical Model ◽  
Prestressed Concrete ◽  
Calculation Method ◽  
Crack Width ◽  
Calculation Model ◽  
Content Type ◽  
Bond Slip ◽  
Stress Calculation ◽  
Bonding Performance

Purpose The calculation of the crack width is necessary for the design of prestressed concrete (PC) members. The purpose of this paper is to develop a numerical model based on the bond-slip theory to calculate the crack width in PC beams. Design/methodology/approach Stress calculation method for common reinforcement after beam crack has occurred depends on the difference in the bonding performance between prestressed reinforcement and common reinforcement. A numerical calculation model for determining the crack width in PC beams is developed based on the bond-slip theory, and verified using experimental data. The calculation values obtained by the proposed numerical model and code formulas are compared, and the applicability of the numerical model is evaluated. Findings The theoretical analysis and experimental results verified that the crack width of PC members calculated based on the bond-slip theory in this study is reasonable. Furthermore, the stress calculation method for the common reinforcement is verified. Compared with the model calculation results obtained in this study, the results obtained from code formulas are more conservative. Originality/value The numerical calculation model for crack width proposed in this study can be used by engineers as a reference for calculating the crack width in PC beams to ensure the durability of the PC member.

scholarly journals The Image-Based Finite Element Evaluation of the Deformed State

2021 ◽  
pp. 44-54
Author(s):  
O. V Vorobiev ◽  
E. V Semenova ◽  
D. A Mukhin ◽  
E. O Statsenko ◽  
T. V Baltina ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Finite Element ◽  
Numerical Model ◽  
Model Problem ◽  
Medical Images ◽  
Test Problems ◽  
Elementary Geometry ◽  
Material Inhomogeneity ◽  
Image Pixels ◽  
Nodal Displacements

The article presents one of the possible approaches to modeling objects with anisotropic properties based on images of the study area. Data from such images are taken into account when building a numerical model. In this case, material inhomogeneity can be included by integrating the local stiffness matrix of each finite element with a certain weight function. The purpose of the presented work is to develop a finite element for the formation of a computational ensemble and simulation of mechanical behavior taking into account the data of two-dimensional medical images. To implement the proposed approach, we used the assumption that there is a correlation between the values in the image pixels and the elastic properties of the material. Meshing was based on a four-node plane finite element. This approach allows using the quantitative phase or scanning electronic images, as well as computed tomography data. A number of test problems for compression of elementary geometry samples were calculated. The distal part of the rat femur was considered as a model problem. A computed tomography scan of the sample was used to construct a numerical model taking into account the inhomogeneity of the material distribution inside the organ. The distribution field of the nodal displacements based on data obtained from the images of the study area is presented. Within the framework of a model problem, we considered how a computer tomograph resolution influences the quality of the obtained results. For this purpose, calculations were carried out based on compressed input medical images.

Mechanical Research on Bond-Slip Behaviors of Recycled Aggregate Concrete-Filled Square Steel Tubes

2012 ◽  
Vol 166-169 ◽  
pp. 3233-3236 ◽  
Author(s):  
Jun Tao Li ◽  
Jin Jun Xu ◽  
Zong Ping Chen ◽  
Yi Li ◽  
Ying Liang
Keyword(s):  
Bond Strength ◽  
Concrete Strength ◽  
Steel Tube ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Replacement Rate ◽  
Steel Tubes ◽  
Aggregate Concrete ◽  
Bond Slip ◽  
Ultimate Bond Strength

In order to research the interface bond-slip behaviors of recycled aggregate concrete-filled square steel tube (RACFSST), ten specimens using waste concrete were designed for launch test. The three changing parameters were concrete strength grade, embedded length and recycled coarse aggregate replacement rate. The load–slip curves of square steel tubes and recycled aggregate concrete were obtained, and starting bond strength and ultimate bond strength influenced by each changing parameter were analyzed. The results show that the replacement rate had a slight influence on the starting bond strength and ultimate bond strength, while the embedded length had the opposite effect. The shorter embedded length specimens had larger bond strength. The concrete strength had a relatively large influence on them.

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