Compressive Performaces of the Concrete Filled Circular CFRP-Steel Tubes (1): Finite Element Simulation and Load Bearing Capacity

This article investigates the behaviour of slender concrete-filled steel tube square columns strengthened by concrete-filled steel tube jacketing. The columns were realised by placing a square outer steel tube around the original slender concrete-filled steel tube column and pouring strengthening concrete into the gap between the inner and outer steel tubes. Three concrete-filled steel tube square columns and seven retrofitted columns ranging from 1200 to 2000 mm were tested to failure under axial compression. The experimental parameters included three length-to-width ( L/ B1) ratios, three width-to-thickness ( B1/ t1) ratios and three strengths of concrete jacket (C50-grade, C60-grade and C70-grade). Experimentally, the retrofitted columns failed in a similar manner to traditional slender concrete-filled steel tube columns. After strengthening, the retrofitted columns benefitted greatly from the component materials, with their load-bearing capacity and ductility notably enhanced. These enhancements were mainly brought about by sectional enlargement and good confinement of concrete. A finite element model was developed using ABAQUS to better understand the axial behaviour of the retrofitted specimens. A parametric study was conducted, with parameters including the length of the column, thickness of the outer steel tube, strength of the concrete jacket, yield strength of the outer steel tube, thickness of the inner steel tube and strength of the inner concrete. Furthermore, the finite element model was adopted to study the behaviour of rust-damaged and post-fire slender concrete-filled steel tube square columns strengthened by square concrete-filled steel tube jacketing. A modified formula was proposed to predict the load-bearing capacity of retrofitted specimens, and the numerical results agreed well with the experiments and the finite element results of undamaged, rust-damaged and post-fire specimens. It could be used as a reference for practical application.

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Numerical and Experimental Study on Deficient Short Steel Tubes Strengthened with CFRP Under Compression

Periodica Polytechnica Civil Engineering ◽

10.3311/ppci.13280 ◽

2019 ◽

Author(s):

Mohammad Reza Ghaemdoust ◽

Omid Yousefi ◽

Kambiz Narmashiri ◽

Masoumeh Karimian

Keyword(s):

Bearing Capacity ◽

Numerical Study ◽

Three Dimensional ◽

Local Buckling ◽

Steel Tubes ◽

Load Bearing Capacity ◽

Load Bearing ◽

Steel Columns ◽

Repair Costs ◽

The Impact

In view of development and repair costs, support of structures is imperative. Several factors, for example, design and calculation errors, absence of appropriate installation, change of structures application, exhaustion, seismic tremor, fire and natural conditions diminish their strength. In such cases, structures have need of rehabilitation and restoration to achieve their original performance. One of the most up to date materials for retrofitting is carbon fiber reinforced polymer (CFRP) that can provide an amount of restriction to postpone buckling of thin steel walls. This paper provides a numerical and experimental investigation on CFRP strengthened short steel tubes with initial horizontal and vertical deficiency under compression. Ten square and circular specimens were tested to study effects of the following parameters: (1) position of deficiency, horizontal or vertical; (2) tube shape, square or circular; (3) CFRP strengthening. In the experiments, axial static loading was gradually applied and for the numerical study three-dimensional (3D) static nonlinear analysis method using ABAQUS software was performed. The results show that deficiency reduces load-bearing capacity of steel columns and the impact of horizontal deficiency is higher than the impact of vertical deficiency, in both square and circular tubes. Use of CFRP materials for strengthening of short steel columns with initial deficiency indicates that fibers play a considerable role on increasing load bearing capacity, reducing stress at the damage location, preventing deformation caused by deficiency and delaying local buckling. Both numerical and experimental outcomes are in good agreement, which underlines the accuracy of the models adopted.

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PLASTIC CAPACITY OF BOLTED RHS FLANGE-PLATE JOINTS UNDER AXIAL TENSION

Engineering Structures and Technologies ◽

10.3846/2029882x.2016.1216806 ◽

2016 ◽

Vol 8 (3) ◽

pp. 85-93

Author(s):

Andrej Mudrov ◽

Gintas Šaučiuvėnas ◽

Antanas Sapalas ◽

Ivar Talvik

Keyword(s):

Finite Element ◽

Bearing Capacity ◽

Load Bearing Capacity ◽

Finite Element Program ◽

Load Bearing ◽

Axial Tension ◽

Flange Thickness ◽

Element Program ◽

Two Sides ◽

Ansys Workbench

This article considers the calculation of load-bearing capacity of flange-plate joints with bolts along two sides of rectangular hollow sections (RHS) under axial tension. It provides a review and comparison of various calculation methodologies for establishing the load-bearing capacity of RHS flange-plate joints, such as suggested in EN 1993-1-8:2005 and STR 2.05.08:2005 as well as those proposed in different countries and by other authors. Common design principles and derived results for load-bearing capacity of flange-plate joints have been analysed and compared. Following the numerical modelling, which has been done using ANSYS Workbench finite element program, the derived results for load-bearing capacity have been compared with analytical load-bearing capacity results for flange-plate joints of the same structure. The analysis has focused on one type of flange-plate joints with bolts – both preloaded and non-preloaded – along two opposite sides of the tube, with the flange thickness of 15 mm and 25 mm.

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Research on Deflection Calculation of Laminated Glass Simply Supported on Four Sides

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.341-342.833 ◽

2011 ◽

Vol 341-342 ◽

pp. 833-837

Author(s):

Xun Wang ◽

Qi Lin Zhang ◽

Jun Chen ◽

Zhi Xiong Tao ◽

Jun Chen

Keyword(s):

Finite Element ◽

Bearing Capacity ◽

Correction Coefficient ◽

Laminated Glass ◽

Load Bearing Capacity ◽

Equivalent Thickness ◽

Curtain Wall ◽

Load Bearing ◽

Simply Supported ◽

Finite Element Software

Combining with load bearing capacity tests, the laminated glass simply supported on four sides subjected to bending is analyzed using the finite element software ANSYS. Based on the theoretical and experimental deflection results, the accurate calculation model is established. In order to calculate the deflection of laminated glass subjected to short-time loading such as wind load based on different codes, the equivalent thickness of laminated glass based on Chinese code 2003 and European code is calculated, respectively. Finally, on the basis of many finite element analyses, load bearing capacity tests and code values, the formulas for calculating maximum deflectiont of four-sides supported laminated glass is revised in “Technical code for glass curtain wall engineering” (China) and corresponding correction coefficient is given.

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Method of Calculation Flexural Stiffness Over Natural Oscillations Frequencies

Archives of Civil Engineering ◽

10.2478/ace-2018-0046 ◽

2018 ◽

Vol 64 (4) ◽

pp. 89-103

Author(s):

A. Nesterenko ◽

G. Stolpovskiy ◽

M. Nesterenko

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Bearing Capacity ◽

Flexural Stiffness ◽

The Finite Element Method ◽

Load Bearing Capacity ◽

Natural Oscillations ◽

Load Bearing ◽

Resonance Frequencies ◽

Element Method

AbstractThe actual load-bearing capacity of elements of a building system can be calculated by dynamic parameters, in particular by resonant frequency and compliance. The prerequisites for solving such a problem by the finite element method (FEM) are presented in the article. First, modern vibration tests demonstrate high accuracy in determination of these parameters, which reflects reliability of the diagnosis. Secondly, most modern computational complexes do not include a functional for calculating the load-bearing capacity of an element according to the input values of resonance frequencies. Thirdly, FEM is the basis for development of software tools for automating the computation process. The article presents the method for calculating flexural stiffness and moment of inertia of a beam construction system by its own frequencies. The method includes calculation algorithm realizing the finite element method.

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Analysis of Load-Bearing Capacity of Initial lining in Tunnels

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.37092 ◽

2021 ◽

Vol 9 (VII) ◽

pp. 3954-3960

Author(s):

MD Waquar Alam

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Bearing Capacity ◽

Element Model ◽

Time Dependent ◽

Load Bearing Capacity ◽

Load Bearing ◽

Full Face ◽

Ground Condition ◽

Drill And Blast

Large displacements during excavation are regularly observed in Squeezing ground condition and Rock-burst condition with high overburden. The expected displacement has to be estimated prior to excavation to provide enough allowance for the displacements. The support system need to be well-suited through the estimated imposed strains. As the estimated displacements and thus the strains in the support depend upon the load-bearing capacity of support. The ratio of uniaxial compressive strength of rock mass to maximal insitu stress determines tunnel integrity in the weak region.This ratio estimates the requirements of initial lining to control strain to a stipulated level. The elasto-plastic theory may deliver definitive forecasts providing the strength limitations of rock masses are identified accurately. With the help of empirical analysis, the development of displacements for diverse advance rates and supports can be concluded. As a consequence, a quantitative finite element model based on an advanced built-in model is designed to analyse the load-bearing efficiency of initial lining although taking into consideration the time-dependent and non-linear material behaviour of initial lining. The time-dependent excavation mechanism of the drill-and-blast approach for tunnels guided by full face excavation is considered in the finite element model. The material parameters for the initial lining were computed based on case studies- (A Chibro-Khodri Hydropower Tunnel).

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Simulation of Performance of CFST Elements Containing Differentiated Profile Tubes Filled with Reinforced Concrete

Materials Science Forum ◽

10.4028/www.scientific.net/msf.968.281 ◽

2019 ◽

Vol 968 ◽

pp. 281-287 ◽

Cited By ~ 3

Author(s):

Glib Vatulia ◽

Alexey Lobiak ◽

Vitaliy Chernogil ◽

Mariia Novikova

Keyword(s):

Finite Element ◽

Reinforced Concrete ◽

Bearing Capacity ◽

Accurate Method ◽

Iteration Algorithm ◽

Stress Strain ◽

Load Bearing Capacity ◽

Limiting State ◽

Load Bearing ◽

The Core

The approach to calculating CFST elements is considered in which physical non-linearity of materials, geometric non-linearity of the tube and the effect of increasing the strength of the core are taken into account. Finite element models are developed and proposed as the basis for more accurate method of calculating concrete-filled steel elements consisting of differentiated profile tubes filled with reinforced concrete. The technique uses a step iteration algorithm involving analytical dependencies and finite element simulation. The criterion for determining the load bearing capacity of CFST elements was the achievement of the stresses in the tube of the characteristic strength. The possibility of estimating the load bearing capacity of elements by limiting stresses in the core concrete is also implemented. The result of the calculations was obtaining the stress-strain and limiting state of the differentiated profile tubes with CFST elements, and graphic analysis of the regularities of stress redistribution at different stages of performance of columns. In general, with the accepted problem statement we could establish the exact stress-strain state, take into account the elastic-plastic deformations of concrete, its cracking and destruction, and geometric nonlinearity of the tube. The effect of performance of the corrugated sheet as a tube was established.

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BUCKLING OF SLENDER COMPOSITE CONCRETE‐FILLED STEEL COLUMNS

Journal of Civil Engineering and Management ◽

10.3846/jcem.2010.26 ◽

2010 ◽

Vol 16 (2) ◽

pp. 230-236 ◽

Cited By ~ 16

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.

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