scholarly journals Finite Element Analysis on Reinforced Concrete Columns Strengthened by ECC Jacketing under Eccentric Compressive Load

2020 ◽  
Vol 24 (5) ◽  
pp. 77-91
Author(s):  
Mohammad Javad Memar ◽  
Ali Kheyroddin ◽  
Ali Hemmati
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Tensile Strain ◽  
Bending Moment ◽  
Concrete Columns ◽  
Load Carrying Capacity ◽  
Normal Concrete ◽  
Eccentric Load ◽  
Load Carrying

Engineered cementitious composite (ECC) can be used for strengthening of concrete columns due to its similar structure and suitable connection to normal concrete and its special tension behavior. In this study, to analyse the columns, finite element (FE) method was used after verification by experimental results. Reference column was strengthened by normal concrete and ECC jacketing. The effects of type of jacket material, longitudinal reinforcement, compressive stress and ultimate tensile strain of ECC on variations of eccentric load-bending moment (P-M) interaction curves were investigated. Results showed that the use of ECC instead of normal concrete can increase load carrying capacity of strengthened column, due to tensile strain hardening behavior of this material. It was found that, amount of this increase depends on eccentricity of eccentric load and varying from 0.4-23%. In ECC jacketing, tensile cracks are continuous, but in concrete jacketing, there were discrete cracks and more quantity of damages. Due to higher load carrying capacity and better distribution of tensile cracks in ECC jacketing than normal concrete jacketing, the use of ECC is suitable for strengthening of reinforced concrete columns. Load carrying capacity of columns under concentric load and pure bending moment were calculated by theoretical method and the results were compared with FE.

scholarly journals Calculation Method for Load-Carrying Capacity of Circular Reinforced Con

2021 ◽  
Vol 353 ◽  
pp. 01013
Author(s):  
Tingwei Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Steel Tube ◽  
Experimental Result ◽  
Load Carrying Capacity ◽  
Model Method ◽  
Concrete Members ◽  
Load Carrying

Finite element method and fiber model method were used to calculate the load-carrying capacity of the specimens. Based on the experimental and theoretical analysis, simplified calculation method of the load-carrying capacity for this kind of member is proposed. It indicates that finite element method result is relatively small, fiber model method result accords well with the experimental result. Circular reinforced concrete members covered with steel tube presents both the characteristics of reinforced concrete and concrete filled steel tube member, showing higher load-carrying capacity and greater deformability. The load-carrying capacity of circular reinforced concrete members covered with steel tube can be calculated by the means of the method of reinforced concrete member with confined concrete. The result predicted by the simplified method is in good agreement with the experimental result.

Improvement of Regulatory Calculation of the Load-Carrying Capacity of Vibrated, Centrifuged, and Vibrocentrifuged-Based Iron-Concrete Columns with Variatropic Structure

2020 ◽  
pp. 78-84
Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
А. А. Чернильник
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Carrying Capacity ◽  
Concrete Columns ◽  
Strength Analysis ◽  
Load Carrying Capacity ◽  
Load Bearing Capacity ◽  
Load Carrying ◽  
Regulatory Approach ◽  
Concrete Elements

Состояние проблемы. Сжатые железобетонные элементы изготавливаются по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что соответствует действительности лишь в вибрированных колоннах. Результаты. Разработан усовершенствованный нормативный подход к расчету прочности центрифугированных и виброцентрифугированных железобетонных колонн, заключающийся в использовании в расчете интегральных или дифференциальных характеристик бетона. Выводы. Расчет прочности коротких центрально сжатых вибрированных, центрифугированных и виброцентрифугированных колонн по усовершенствованному нормативному подходу дал наилучшие результаты с использованием дифференциальных характеристик бетона, различающихся по сечению. Statement of the problem. Compressed reinforced concrete elements are manufactured according to three main technologies - vibrating, centrifuging and vibrocentrifugation. However, all the main calculated dependences for determining their load-bearing capacity were derived based on the main postulate - the constancy and equality of the characteristics of concrete over the cross section, which corresponds to reality only in vibrated columns. Results. An improved regulatory approach has been developed for calculating the strength of centrifuged and vibrocentrifuged reinforced concrete columns, which involves using the calculation of integral or differential characteristics of concrete. Conclusions. Strength analysis of short centrally compressed vibrated, centrifuged and vibrocentrifuged columns using an improved regulatory approach yielded the best results using differential characteristics of concrete varying in cross section.

Design Parameter Reliability Analysis of Induction Bends

2014 ◽  
Author(s):  
Venkata M. K. Akula ◽  
Lance T. Hill
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Reliability Analysis ◽  
Carrying Capacity ◽  
Design Variable ◽  
Bending Moment ◽  
Load Carrying Capacity ◽  
Element Analysis ◽  
Design Variables ◽  
Load Carrying

Induction pipe bends are essential multi-functional components in offshore applications performing not only as fluid conductors but also as structural members providing flexibility to the entire pipeline. The deforming mechanism of bends minimizes the effects of pipe walking, length changes due to thermal expansion/contraction, etc. However, the extent to which the bend deforms to counteract the pipeline deformation, prior to reaching plastic collapse, is dictated by the design variables. The pipe bend design variables include the geometry of the bend, the inelastic material properties, and the operating loads. The study of the influence of these variables is central to improving upon existing bend designs and is the focus of this research. The certification process for bends typically involves ensuring the pipe bending moment is within limits set by agencies such as DNV, ASME, etc. Closed form solutions for the bending moment do exist but they often do not consider the effects of large deformation and the material nonlinearity of the bends. Since it is impractical to perform physical tests for every possible design, numerical techniques such as the finite element methods are an attractive alternative. Furthermore, for a given bend design, the design variables are prone to deviation, due to manufacturing process, operating conditions, etc., which introduces variation in the structural response and the resulting bending moment. In this paper, a nonlinear finite element analysis of induction bends is discussed followed by a presentation of a simulation workflow and reliability analysis. The finite element analysis utilizes a nonlinear Abaqus model with an user-subroutine prescribing precise end loading and boundary conditions. The workflow utilizes the design exploration software, Isight, which automates the solution process. Thereafter, reliability analysis is performed by varying the design variables, such as bend angle, ovalization, etc. and the results of the simulation are presented. The objective is to illustrate a solution technique for predicting the induction bend load carrying capacity and to examine design robustness. An automated workflow is demonstrated which allows for quick design variable changes, there by potentially reducing design time. The reliability analysis allows analysts to measure the variation in the load carrying capacity resulting from the deviation of design variable specifications. These demonstrations are intended to emphasize that to ensure the success of a bend design, it is important to not only predict the load carrying capacity accurately but also to perform reliability analysis for the design.

Prediction of axial load-carrying capacity of GFRP-reinforced concrete columns through artificial neural networks

Structures ◽  
2020 ◽  
Vol 28 ◽  
pp. 1557-1571
Author(s):  
Ali Raza ◽  
Syyed Adnan Raheel Shah ◽  
Faraz ul Haq ◽  
Hunain Arshad ◽  
Syed Safdar Raza ◽  
...  
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Axial Load ◽  
Concrete Columns ◽  
Load Carrying Capacity ◽  
Reinforced Concrete Columns ◽  
Load Carrying ◽  
Artificial Neural

Reinforcement of Damaged Concrete Columns by Filament Winding of Thermoplastic Composites

2002 ◽  
Vol 10 (4) ◽  
pp. 273-280
Author(s):  
K. Friedrich ◽  
N. Glienke ◽  
J. Flöck ◽  
F. Haupert ◽  
S. A. Paipetis
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Columns ◽  
Reinforce Concrete ◽  
Filament Winding ◽  
Thermoplastic Composites ◽  
Concrete Column ◽  
Load Carrying Capacity ◽  
Composite Systems ◽  
Load Carrying

An experimental study was conducted to compare various composite systems with different fibres (E-glass and carbon) in two different thermoplastic matrices (PPS, PEEK) for their strengthening efficiency for wrapped concrete columns. The results indicated that the use of E-glass fibres within a polyphenylenesulfide matrix to externally reinforce concrete columns is quite effective. The carbon fibre PEEK based system does not show much improvement in the load carrying capacity. The thickness of wrap/radius of concrete column-ratio also has an influence on the strengthening efficiency. For example ten layers of glass fibre/PPS-tapes resulted in a five fold improvement of the compressive strength of the non-reinforced concrete. Predamaged samples with the same amount of reinforcement were still 4.5 times stronger than the undamaged, non-reinforced concrete.

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