NONLINEAR ANALYSIS OF A BARBELL-SHAPED CROSS SECTION WALL USING FIBER SLICE

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Dae-Han Jun ◽  
Pyeong-Doo Kang
Keyword(s):  
Reinforced Concrete ◽  
Analytical Model ◽  
Cross Section ◽  
Cross Sections ◽  
Axial Load ◽  
Nonlinear Response ◽  
Shear Walls ◽  
Lateral Loads ◽  
Fiber Element ◽  
Shaped Cross Section

Reinforced concrete shear walls are effective for resisting lateral loads imposed by wind or earthquakes. This study investigates the effectiveness of a wall fiber element in predicting the flexural nonlinear response of reinforced concrete shear walls. Model results are compared with experimental results for reinforced concrete shear walls with barbell-shaped cross sections without axial load. The analytical model is calibrated and the test measurements are processed to allow for a direct comparison of the predicted and measured flexural responses. Response results are compared at top displacements on the walls. Results obtained in the analytical model for barbell-shaped cross section wall compared favorably with experimentally responses for flexural capacity, stiffness, and deformability.

scholarly journals Assessment of ultimate drift capacity of RC shear walls by key design parameters

2017 ◽  
Vol 50 (4) ◽  
pp. 482-493 ◽  
Author(s):  
Chanipa Netrattana ◽  
Rafik Taleb ◽  
Hidekazu Watanabe ◽  
Susumu Kono ◽  
David Mukai ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Axial Load ◽  
Concrete Strength ◽  
Shear Walls ◽  
Load Ratio ◽  
Design Parameters ◽  
Seismic Behaviour ◽  
Drift Capacity ◽  
Axial Load Ratio

The latest version of the Standard for Structural Calculation of Reinforced Concrete Structures, published by the Architectural Institute of Japan in 2010 [1], allows the design of shear walls with rectangular cross sections in addition to shear walls with boundary columns at the end regions (referred to here as “barbell shape”). In recent earthquakes, several reinforced concrete (RC) shear walls were damaged by flexural failures through concrete compression crushing accompanied with buckling of longitudinal reinforcement in the boundary areas. Damage levels have clearly been shown to be related to drift in structures; this is why drift limits are in place for structural design criteria. A crucial step in designing a structure to accommodate these drift limits is to model the ultimate drift capacity. Thus, in order to reduce damage from this failure mode, the ultimate drift capacity of RC shear walls needs to be estimated accurately. In this paper, a parametric study of the seismic behaviour of RC shear walls was conducted using a fibre-based model to investigate the influence of basic design parameters including concrete strength, volumetric ratio of transverse reinforcement in the confined area, axial load ratio and boundary column dimensions. This study focused on ultimate drift capacity for both shear walls with rectangular sections and shear walls with boundary columns. The fibre-based model was calibrated with experimental results of twenty eight tests on shear walls with confinement in the boundary regions. It was found that ultimate drift capacity is most sensitive to axial load ratio; increase of axial load deteriorated ultimate drift capacity dramatically. Two other secondary factors were: increased concrete strength slightly reduced ultimate drift capacity while increased shear reinforcement ratio and boundary column width improved ultimate drift capacity.

An analytical model of a curved beam with a T shaped cross section

2018 ◽  
Vol 416 ◽  
pp. 29-54 ◽  
Author(s):  
Andrew J. Hull ◽  
Daniel Perez ◽  
Donald L. Cox
Keyword(s):  
Analytical Model ◽  
Cross Section ◽  
Curved Beam ◽  
Shaped Cross Section

scholarly journals Behavior of Columns Confined With FRP Fabrics under Repeated Lateral Loads

2019 ◽  
pp. 1-19
Author(s):  
Hesham A. Haggag ◽  
Nagy F. Hanna ◽  
Ghada G. Ahmed
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Axial Load ◽  
Axial Loading ◽  
Concrete Columns ◽  
Fiber Reinforced Polymers ◽  
Lateral Loads ◽  
Reinforced Concrete Columns ◽  
Reinforced Polymers ◽  
Axial Capacity

The axial strength of reinforced concrete columns is enhanced by wrapping them with Fiber Reinforced Polymers, FRP, fabrics.  The efficiency of such enhancement is investigated for columns when they are subjected to repeated lateral loads accompanied with their axial loading.  The current research presents that investigation for Glass and Carbon Fiber Reinforced Polymers (GFRP and CFRP) strengthening as well.  The reduction of axial loading capacity due to repeated loads is evaluated. The number of applied FRP plies with different types (GFRP or CFRP) are considered as parameters in our study. The study is evaluated experimentally and numerically.  The numerical investigation is done using ANSYS software. The experimental testing are done on five half scale reinforced concrete columns.  The loads are applied into three stages. Axial load are applied on specimen in stage 1 with a value of 30% of the ultimate column capacity. In stage 2, the lateral loads are applied in repeated manner in the existence of the vertical loads.  In the last stage the axial load is continued till the failure of the columns. The final axial capacities after applying the lateral action, mode of failure, crack patterns and lateral displacements are recorded.   Analytical comparisons for the analyzed specimens with the experimental findings are done.  It is found that the repeated lateral loads decrease the axial capacity of the columns with a ratio of about (38%-50%).  The carbon fiber achieved less reduction in the column axial capacity than the glass fiber.  The column confinement increases the ductility of the columns under the lateral loads.

scholarly journals Reconciling Architectural Design with Seismic Codes

Prostor ◽  
2021 ◽  
Vol 29 (1 (61)) ◽  
pp. 42-55
Author(s):  
Cengiz Özmen
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Cross Sections ◽  
Architectural Design ◽  
Residential Buildings ◽  
Shear Walls ◽  
Spatial Arrangement ◽  
Design Principles ◽  
Seismic Codes ◽  
Architectural Analysis

Seismic codes include strict requirements for the design and construction of mid-rise reinforced concrete residential buildings. These requirements call for the symmetric and regular arrangement of the structural system, increased cross-sections for columns, and the introduction of shear walls to counteract the effects of lateral seismic loads. It is challenging for architects to reconcile the demands of these codes with the spatial arrangement and commercial appeal of their designs. This study argues that such reconciliation is possible through an architectural analysis. First, the effectiveness of applying the seismic design principles required by the codes is demonstrated with the comparative analysis of two finite element models. Then three pairs of architectural models, representing the most common floor plan arrangements for such buildings in Turkey, are architecturally analyzed before and after the application of seismic design principles in terms of floor area and access to view. The results demonstrate that within the context defined by the methodology of this study, considerable seismic achievement can be achieved in mid-rise reinforced concrete residential buildings by the application of relatively few, basic design features by the architects.

Two-discrete-elements concrete shear deformation model: Formulation and application in the seismic evaluation of reinforced concrete shear walls

2020 ◽  
Vol 23 (16) ◽  
pp. 3429-3445
Author(s):  
Fadi Oudah ◽  
Raafat El-Hacha
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Deformation ◽  
Axial Load ◽  
Shear Deformation Theory ◽  
Shear Walls ◽  
Shear Capacity ◽  
Complex Nature ◽  
Deformation Model ◽  
Discrete Elements

Shear deformation in reinforced concrete structures is of a complex nature. A thorough understanding of the interaction between the shear strength, flexural strength, and flexural ductility is not yet achieved. A new shear-deformation-based theory is proposed and validated in this study. The so-called two-discrete-elements (TDE) shear deformation theory idealizes reinforced concrete members as series of two discrete types of elements: S-elements and C-elements. The S-elements are used to model the regions of concrete reinforced to resist flexural and shear deformation using longitudinal and transverse steel reinforcement, while the C-elements are used to model the reinforced concrete sections bounded by the stirrups. The compatibility between the two types of elements is enforced by controlling the crack angle. The formulation of the newly developed theory is discussed in terms of equilibrium of forces, compatibility within the elements, compatibility at the interface, and constitutive material modeling. The theory was applied to evaluate the deformability of reinforced concrete shear walls subjected to lateral loads for seismic design applications. It was also implemented to generate sample design charts referred to as axial–moment–shear interaction diagrams. These diagrams can be used to design shear walls subjected to combined action of axial load, moment, and shear as opposed to the conventional interaction diagrams in which only the axial load versus moment relationship is considered. Analysis results indicated the adequacy of the proposed theory in capturing the shear strength degradation and predicting structural failures controlled by the shear capacity.

scholarly journals Investigation of Parameters Affecting the Equivalent Yield Curvature of Reinforced Concrete Columns

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1594
Author(s):  
Umut Hasgul
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Axial Load ◽  
Concrete Columns ◽  
Load Level ◽  
Combined Effects ◽  
Reinforced Concrete Columns ◽  
Independent Effects ◽  
Equivalent Yield ◽  
Section Dimension

In this study, the response quantities affecting the equivalent yield curvature, which is important in the deformation-based seismic design and assessment of structural systems, are investigated for reinforced concrete columns with a square cross-section. In this context, the equivalent yield curvatures were determined by conducting moment–curvature analyses on various column models, in which the axial load level, cross-section dimension, longitudinal reinforcement ratio, and concrete compression strength were changed parametrically, and the independent and/or combined effects of the relevant parameters were discussed. Depending on the axial load levels of P/Agfc′ < 0.3, P/Agfc′ = 0.3, and P/Agfc′ > 0.3 for the considered columns, the yielding of reinforcement, yielding of reinforcement and/or concrete crushing, and concrete crushing governed the yield conditions, respectively. It can be noted that the cross-section dimension and axial load level became the primary parameters. Even though the independent effects with regard to particular parameters remained at minimal levels, the combined effects of them with the axial load became important in terms of the equivalent yield curvature.

scholarly journals Numerical Modelling of Thermal Insulation of Reinforced Concrete Ceilings with Complex Cross-Sections

2020 ◽  
Vol 10 (8) ◽  
pp. 2642 ◽  
Author(s):  
Łukasz Drobiec ◽  
Rafał Wyczółkowski ◽  
Artur Kisiołek
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Cross Sections ◽  
Good Alternative ◽  
Numerical Analyses ◽  
The Finite Element Method ◽  
Equivalent Thermal Conductivity ◽  
Air Voids ◽  
Complex Cross ◽  
Calculation Results

The article describes the results of numerical analyses and traditional calculations of the heat transfer coefficient in ceilings with a complex cross-section, and with materials of varying density built-in inside the cross-section. Prefabricated prestressed reinforced concrete, composite reinforced, and ribbed reinforced concrete ceilings were analyzed. Traditional calculations were carried out in accordance with the EN ISO 6946:2017 standard, while the numerical analyses were carried out in a program based on the finite element method (FEM). It has been shown that calculations can be a good alternative to nondestructive testing (NDT) and laboratory tests, whose use in the case of ceilings with different geometries is limited. The differences between the calculations carried out in accordance with EN ISO 6946:2017, and the results of numerical analyses are 12%–39%. The way the air voids are taken into account has an impact on the calculation results. In the traditional method, an equivalent thermal conductivity coefficient was used, while in the numerical analysis, the coefficient was selected from the program’s material database. Since traditional calculations require simplifications, numerical methods should be considered to give more accurate results.

Parametric Study of Reinforced Concrete Column Cross-Section for Strength and Ductility

2008 ◽  
Vol 400-402 ◽  
pp. 269-274 ◽  
Author(s):  
Naveed Anwar ◽  
Mohammad Qaasim
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Cross Sections ◽  
Strain Curve ◽  
Concrete Column ◽  
Loading Conditions ◽  
Reinforced Concrete Column ◽  
Section Shape ◽  
And Performance ◽  
Strength And Ductility

Several parameters and corresponding performance of reinforced concrete column cross-sections of different shapes (square, rectangular, circular, T-shape, I-shape, cross-shape, L-shape and C-shape) under various loading conditions have been studied in order to determine the suitable and optimum cross-sections for strength and ductility. In each cross-section shape, parameters include compressive strength of concrete (f’c), tensile strength of steel (fy), steel ratio (As/Ag), and angle of bending. In order to demonstrate the behavior and performance of the sections in terms of strength and ductility, CSISectionBuilder software was used to define the stress-strain curve for concrete and steel and then compute the moment-curvature relationship for each section. Considering different sections, the number of parameters in every section and various loading conditions, a total of around 1,800 sections were analyzed. The comparison procedures started within each section shape, and then across different sections in order to determine the most suitable cross-section for strength and ductility. Results of the study are deemed very useful in the system selection and preliminary design of important structures such as buildings with complicated geometry and high architectural demand including bridge piers and hydraulic structures.

scholarly journals Numerical Simulation of Reinforced Concrete Shear Walls Using Force-Based Fiber Element Method

2021 ◽  
Author(s):  
MUHAMMET KARATON ◽  
Ömer Faruk Osmanlı ◽  
Mehmet Eren GÜLŞAN
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Shear Walls ◽  
Shear Wall ◽  
Roof Displacement ◽  
Experimental Results ◽  
Wall Structures ◽  
Longitudinal Length ◽  
Fiber Element ◽  
Element Method

Abstract Reinforced concrete shear walls are the structural elements that considerably increase the seismic performance of buildings. Fiber elements and fiber-spring elements are used for the modeling of the inelastic behavior of these elements. The Fiber Element Method provides a certain amount of accuracy for the modeling of reinforced concrete shear walls. However, the studies related to this method are still in progress. In this study, the efficiency of the force-based Fiber Element Method is investigated for different damping ratios and different damping types that used in the structural damping for reinforced concrete shear wall structures. Two shear wall structures that subjected to seismic loads are used for the comparison of numerical analysis and experimental results. The comparisons are achieved according to the absolute maximum values of the overturning moment, the base shear force, and the roof displacement. Rayleigh damping and stiffness-proportional damping types for the damping ratios that vary between 2-3% provide better results than mass-proportional damping. Additionally, the optimum number of fiber element for Rayleigh and stiffness-proportional damping types is determined for the optimum damping ratio that provides minimum differences between numerical analysis and experimental results. For these damping types, when the length of a fiber is smaller than 3% of the longitudinal length of the shear wall at the optimum damping ratios, the roof displacement differences between numerical analysis and experimental results are less than 2.5%.

scholarly journals The determination of normal stresses in cross-sections of the three-flue reinforced concrete chimney

2008 ◽  
Vol 3 (2) ◽  
pp. 081-095
Author(s):  
Małgorzata Dobrowolska ◽  
Marta Słowik
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Cross Sections ◽  
Analytical Form ◽  
Normal Stresses ◽  
Full Cross Section ◽  
Steel Bars ◽  
Reinforced Concrete Chimney ◽  
Physical Laws

In the paper there is presented the algorithm of calculation of normal stresses in reinforced concrete three-flue chimney. The calculation has been made for full cross-section and for cross-section weakened by openings. The governing equations has been derived in an analytical form assuming linear physical laws for concrete and steel and, as for as considered cross-section weakened by openings, taking into account the additional reinforcing steel bars at the openings. In addition coefficients B and C have been determined, which are useful at dimensioning.

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