Predicting the Strength of Rectangular Reinforced Concrete Columns Confined with FRP Sheets

2022 ◽  
Vol 906 ◽  
pp. 17-23
Author(s):  
Ashot G. Tamrazyan ◽  
Yehia A.K. Sayed
Keyword(s):  
Compressive Strength ◽  
Regression Analysis ◽  
Concrete Columns ◽  
Test Results ◽  
Rc Columns ◽  
New Model ◽  
Proposed Model ◽  
Axial Compressive Strength ◽  
Frp Sheet ◽  
Good Agreement

A complete reorganization about the behavior of rectangular RC columns confined with FRP sheet is very important to predict the axial compressive strength values of the strengthened rectangular RC columns. That is because the process of strengthening RC rectangular column depending on several parameters that role this type of strengthening. These parameters include the characteristics of the used fiber, the grade of concrete and the geometry of the cross section including the rectangularity aspect ratio, corner radius, and size of specimens. Besides that, using a wide scope of experimental data may affect positively to generalize a model that considers the whole parameters affect the value of the axial strength. So, in this paper a review about parameters that affect the axial compressive strength values of rectangular RC columns was conducted. After that, based on the test results regarding FRP-confined rectangular RC columns available in the literature or conducted by the author, some existing confinement models for rectangular RC columns were assessed. Further, a new model is proposed through regression analysis of the database. A new model is proposed through regression analysis of the database. The proposed model was found to be in good agreement with the test results in the database. Finally, based on the results conclusions were drawn.

Tests and Numerical Simulation on Short Composite-Sectioned Concrete Filled Steel Tubular Columns Subjected to Axial Compressive Loading

2011 ◽  
Vol 374-377 ◽  
pp. 2265-2270
Author(s):  
Yang Zhang ◽  
Jia Ru Qian ◽  
Xiao Dong Ji ◽  
Wan Lin Cao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compressive Strength ◽  
Compressive Loading ◽  
Steel Tube ◽  
Test Results ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Axial Compressive Strength ◽  
Good Agreement

In this paper, axial compressive loading test and non-linear finite element analysis of 10 short composite-sectioned concrete filled steel tubular column specimens are introduced. The test results indicate that the failure modes of all the specimens are similar, the specimens have high axial compressive strength and large deformation capacity. The calculated axial compressive strength of the specimens, assuming that the circle steel tube provides the lateral confinement to the core concrete and the square steel tube provides compressive strength without contributing lateral confinement to the concrete, has good agreement with the measured strength. The vertical load-strain curves, the axial compressive strength and the failure mode obtained by the non-linear finite element analysis of specimens have good agreement with the test results.

Analysis and Validation of Cutting Forces Prediction Models in Micromachining

2006 ◽  
Vol 526 ◽  
pp. 13-18 ◽  
Author(s):  
H. Perez ◽  
Antonio Vizan Idoipe ◽  
J. Perez ◽  
J. Labarga
Keyword(s):  
Experimental Data ◽  
Cutting Force ◽  
Cutting Forces ◽  
Prediction Models ◽  
Precision Machining ◽  
New Model ◽  
Proposed Model ◽  
On Line ◽  
Machine Control ◽  
Good Agreement

Many investigations have been developed related to precision machining with features in the millimetre scale. In this paper different cutting force models for micromilling are analyzed and compared. A new model based on specific cutting force that also considers run-out errors has been developed. The estimated cutting forces obtained with this model had good agreement with the experimental data. Also, the proposed model allows to be implemented within the machine control for the on-line optimization of the micromilling process.

Mathematical Modeling of Ultra-High-Pressure Waterjet Peening

2005 ◽  
Vol 127 (2) ◽  
pp. 186-191 ◽  
Author(s):  
S. Kunaporn ◽  
M. Ramulu ◽  
M. Hashish
Keyword(s):  
Mathematical Modeling ◽  
High Pressure ◽  
High Cycle Fatigue ◽  
Fatigue Tests ◽  
Analytical Models ◽  
Test Results ◽  
Ultra High Pressure ◽  
Proposed Model ◽  
Compressive Residual Stresses ◽  
Good Agreement

Waterjet peening is a recent promising method in surface treatment. It has the potential to induce compressive residual stresses that benefit the fatigue life of materials similar to the conventional shot peening process. However, there are no analytical models that incorporate process parameters (i.e., supply pressure, jet exposure time, and nozzle traverse rate, etc) to allow predicting the optimized peening process. Mathematical modeling of high-pressure waterjet peening was developed in this study to describe the relation between the waterjet peening parameters and the resulting material modifications. Results showed the possibility of using the proposed mathematical model to predict an initial range for effective waterjet peening under the variation of waterjet peening conditions. The high cycle fatigue tests were performed to validate the proposed model and fatigue test results showed good agreement with the predictions.

scholarly journals BEHAVIOUR OF HIGH-STRENGTH CONCRETE CIRCULAR COLUMNS CONFINED BY HIGH-STRENGTH SPIRALS UNDER CONCENTRIC COMPRESSION

2020 ◽  
Vol 26 (6) ◽  
pp. 564-578
Author(s):  
Chongchi Hou ◽  
Wenzhong Zheng ◽  
Wei Chang
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Concrete Columns ◽  
Confined Concrete ◽  
Concrete Compressive Strength ◽  
Strength Concrete ◽  
Proposed Model ◽  
High Strength Concrete Columns

This paper tested the behaviour of 32 high-strength concrete columns confined by high-strength spirals under concentric compression. The test parameters included unconfined concrete compressive strength, spiral yield strength, volumetric ratio, and spiral spacing. The results showed that bulging and shear sliding were the two characteristic types of failure patterns of the thirty-two confined columns, depending on spiral spacing and concrete strength. Moreover, the spiral in most specimens did not yield at the confined concrete compressive strength. An analytical confinement model for high-strength concrete columns confined by high-strength spirals was proposed. In this proposed model, the calculated value of the spiral stress at the confined concrete compressive strength was used to calculate the feature points of the stressstrain curve. The proposed model showed good correlations with available experimental results of 64 columns.

scholarly journals New model for compressive strength loss of lightweight concrete exposed to elevated temperatures

2019 ◽  
Vol 23 (Suppl. 1) ◽  
pp. 285-293 ◽  
Author(s):  
Ahmet Kurtoglu ◽  
Derya Bakbak
Keyword(s):  
Compressive Strength ◽  
Elevated Temperatures ◽  
Lightweight Concrete ◽  
Strength Loss ◽  
Cooling Regime ◽  
New Model ◽  
Aggregate Content ◽  
Proposed Model ◽  
Data Points ◽  
Temperature Water

This study proposes a new model for the residual compressive strength of structural lightweight concrete after exposure to elevated temperatures up to 1000?C. For this purpose, a database of residual compressive strengths of fire exposed lightweight concrete was compiled from the literature. Database consisted a total number of 289 data points, used for generating training and testing datasets. Symbolic regression was carried out to generate formulations by accounting for various input parameters such as heating rate, cooling regime, target temperature, water content, aggregate type, and aggregate content. Afterwards, predictions of proposed formulation is compared to experimental results. Statistical evaluations verify that the prediction performance of proposed model is quite high.

scholarly journals Response of RPC-Filled Circular Steel Tube Columns under Monotonic and Cyclic Axial Loading

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Qin Rong ◽  
Yusheng Zeng ◽  
Lanhui Guo ◽  
Xiaomeng Hou ◽  
Wenzhong Zheng
Keyword(s):  
Compressive Strength ◽  
Cyclic Loading ◽  
Axial Loading ◽  
Steel Tube ◽  
Test Results ◽  
Confining Effect ◽  
Circular Steel Tube ◽  
Axial Compressive Strength ◽  
Reactive Powder ◽  
Elastic Stage

Results from mechanical tests on thirteen reactive powder concrete- (RPC-) filled circular steel tube (RFCT) columns under monotonic and cyclic axial loading are presented in this paper. The test variables include monotonic and cyclic loadings, confinement coefficient, and diameter of the steel tube. The test results show that the envelope curves of specimens under cyclic loading were similar to the load-deformation curves of the specimens under monotonic loading. Confinement coefficient had a significant influence on the failure modes of RFCT columns. With an increase in confinement coefficient of 0.53 to 0.98, the failure mode transformed from shear failure to compressive failure for specimens under monotonic and cyclic loading. In the elastic stage, no confining effect was provided by the steel tube to the RPC since Poisson’s ratio of steel was larger than the transverse deformation coefficient of RPC. Beyond the elastic stage, the axial compressive strength and ultimate strain of RPC increased significantly due to the confining effect when compared to unconfined RPC. Stress of the steel tube and RPC was investigated by using an elastic-plastic analytical model. Before yielding of the steel tube, stress development in the tube was faster in the longitudinal direction than in the hoop direction. The results of the experiment indicate that the compressive strength of RPC could be predicted by Mander’s model for confined concrete. Based on Mander’s model, an equation is extended to calculate the axial compressive strength of RFCT columns, and the predicted results are in good agreement with the test results. Based on comparative analysis of 180 RFCT columns axial compressive tests, the equation given by EC4 considering the confinement effect can be applied to predict the compressive strength of RFCT columns.

Experimental Study on Compressive Bearing Capacity of High Strength Concrete-Filled Steel Tube Composite Columns

2011 ◽  
Vol 368-373 ◽  
pp. 410-414 ◽  
Author(s):  
Hong Zhen Kang ◽  
Lei Yao ◽  
Xi Min Song ◽  
Ying Hua Ye
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Strength Concrete ◽  
High Strength ◽  
Steel Tube ◽  
Test Results ◽  
Concrete Filled Steel Tube ◽  
Composite Columns ◽  
Strength Concrete ◽  
Axial Compressive Strength

To study axial compressive strength of high strength concrete-filled steel tube composite columns, tests of 18 specimens were carried out. Parameters of the specimens were the confinement index of concrete-filled steel tube, the cubic strength and the stirrup characteristic value of concrete outer of steel tube. Test results show that the concrete-filled steel tube and the reinforced concrete deformed simultaneously in the axial direction before and at the peak value of axial compressive force; after failure of the reinforced concrete, the concrete-filled steel tube can still bear the axial load and deformation; the main influential factors of axial compressive capacity are confinement index, the cubic strength and the stirrup characteristic value of concrete outer of steel tube. The accuracy of the formula of axial compressive strength of composite columns provided by CECS 188:2005 is proved by the test results of this paper.

Modelling and Analysis of Capacitive Effects in a High Frequency Coaxial Transformer

2012 ◽  
Vol 466-467 ◽  
pp. 607-611
Author(s):  
Xiao Guang Yang
Keyword(s):  
Energy Storage ◽  
Electromagnetic Interference ◽  
High Frequency ◽  
Electric Energy ◽  
Experimental Results ◽  
Voltage Distribution ◽  
New Model ◽  
Electric Energy Storage ◽  
Proposed Model ◽  
Good Agreement

A new model is proposed for analyzing the capacitive effects in a newly developed high frequency coaxial transformer (HFCT). The proposed model can describe both the electric energy storage and common-mode (CM) electromagnetic interference (EMI) noise behaviors of a transformer, considering the voltage distribution in the HFCT windings. To determine the parameters of the model, a parasitic capacitance network is developed to describe the HFCT’s real winding’s structure, and the distributed parasitic capacitances of the network are evaluated using FEM based on the theory of capacitances in a multi-conductor system. The calculated inter-capacitance of the HFCT is in good agreement with the experimental results.

Study on Ultimate Bearing Capacity of Reinforced Concrete Columns Combined with FRP

2011 ◽  
Vol 94-96 ◽  
pp. 820-825
Author(s):  
Sai Wu ◽  
Jun Hai Zhao ◽  
Xue Ying Wei
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Columns ◽  
Ultimate Bearing Capacity ◽  
Axial Loads ◽  
Strength Theory ◽  
Rc Columns ◽  
Reinforced Concrete Columns ◽  
Unified Strength Theory ◽  
Good Agreement

This paper based on the unified strength theory, analyzed the ultimate bearing capacity of the reinforced concrete columns combined with FRP under axial loads. First, analyzed the mechanical property of the RC columns combined with FRP. Second, based on the unified strength theory, deduced the three-direction compressive stress of the core concrete and got the unified formula for calculating the ultimate bearing capacity of RC columns combined with FRP. Last, compared the analytical results obtained in this paper with the relevant experimental data, good agreement can be found and it proved the good applicability of the formula. Comparing with other methods in calculating the ultimate bearing capacity of RC columns combined with FRP，this method is well-founded, so it has a significant value in analysis of RC columns combined with FRP.

scholarly journals Analytical Review on Eccentric Axial Compression Behavior of Short and Slender Circular RC Columns Strengthened Using CFRP

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2763
Author(s):  
Muhammad Abid ◽  
Haytham F. Isleem ◽  
Muhammad Kamal Kamal Shah ◽  
Shayan Zeb
Keyword(s):  
Reinforced Concrete ◽  
Axial Compression ◽  
Slenderness Ratio ◽  
Concrete Columns ◽  
Practice Research ◽  
Small Scale ◽  
Stress Strain ◽  
Eccentric Load ◽  
Rc Columns ◽  
Proposed Model

Although reinforced concrete (RC) columns subjected to combined axial compression and flexural loads (i.e., eccentric load) are the most common structural members used in practice, research on FRP-confined circular RC columns subjected to eccentric axial compression has been very limited. More specifically, the available eccentric-loading models were mainly based on existing concentric stress–strain models of FRP-confined unreinforced concrete columns of small scale. The strength and ductility of FRP-strengthened slender circular RC columns predicted using these models showed significant errors. In light of such demand to date, this paper presents a stress–strain model for FRP-confined circular reinforced concrete (RC) columns under eccentric axial compression. The model is mainly based on observations of tests and results reported in the technical literature, in which 207 results of FRP-confined circular unreinforced and reinforced concrete columns were carefully studied and analyzed. A model for the axial-flexural interaction of FRP-confined concrete is also provided. Based on a full parametric analysis, a simple formula of the slenderness limit for FRP-strengthened RC columns is further provided. The proposed model considers the effects of key parameters such as longitudinal and hoop steel reinforcement, level of FRP hoop confinement, slenderness ratio, presence of longitudinal FRP wraps, and varying eccentricity ratio. The accuracy of the proposed model is finally validated through comparisons made between the predictions and the compiled test results.

Sign in / Sign up

Export Citation Format

Share Document