scholarly journals Application of Post-Embedded Piezoceramic Sensors for Force Detection on RC Columns under Seismic Loading

2020 ◽  
Vol 10 (15) ◽  
pp. 5061
Author(s):  
Chien-Kuo Chiu ◽  
Chia-Hsin Wu ◽  
Hsin-Fang Sung ◽  
Wen-I Liao ◽  
Chih-Hsien Lin
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Seismic Loading ◽  
Applied Force ◽  
Seismic Capacity ◽  
Force Detection ◽  
Rc Columns ◽  
Full Size ◽  
Rc Column ◽  
The Relationship

To quantify damage to reinforced concrete (RC) column members after an earthquake, an engineer needs to know the maximum applied force that was generated by the earthquake. Therefore, in this work, piezoceramic transducers were used to detect the applied force on an RC column member under dynamic loading. To investigate the use of post-embedded piezoceramic sensors in detecting the force that is applied to RC columns, eight full-size RC column specimens with various failure modes were tested under specific earthquake loadings. Post-embedded piezoceramic sensors were installed at a range of depths (70–80 mm) beneath the surface of a column specimen to examine the relationship between the signals that were obtained from them and the force applied by the dynamic actuator. The signals that were generated by the post-embedded piezoceramic sensors, which correlate with the applied force, are presented. These results indicate that the post-embedded piezoceramic sensors have great potential as tools for measuring the maximum applied force on an RC column in an earthquake. In other words, signals that are obtained from post-embedded piezoceramic sensors on an RC column in an earthquake can be used to determine the applied force and corresponding damage or residual seismic capacity.

scholarly journals Application of Post-Embedded Piezoceramic Sensors for Force Detection on RC Columns under Seismic Loading

2020 ◽  
Author(s):  
Chien-Kuo Chiu ◽  
Chia-Hsin Wu ◽  
Hsin-Fang Sung ◽  
Wen-I Liao ◽  
Chih-Hsien Lin
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Seismic Loading ◽  
Applied Force ◽  
Seismic Capacity ◽  
Force Detection ◽  
Rc Columns ◽  
Full Size ◽  
Rc Column ◽  
The Relationship

To quantify damage to reinforced concrete (RC) column members after an earthquake, an engineer needs to know the maximum applied force that was generated by the earthquake. Therefore, in this work, piezoceramic transducers are used to detect the applied force on an RC column member under dynamic loading. To investigate the use of post-embedded piezoceramic sensors in detecting the force that is applied to RC columns, eight full-size RC column specimens with various failure modes are tested under specific earthquake loadings. Post-embedded piezoceramic sensors are installed at a range of depths (70-80 mm) beneath the surface of a column specimen to examine the relationship between the signals that are obtained from them and the force applied by the dynamic actuator. The signals that are generated by the post-embedded piezoceramic sensors, which correlate with the applied force, are presented. These results indicate that the post-embedded piezoceramic sensors have great potential as tools for measuring the maximum applied force on an RC column in an earthquake. Restated, signals that are obtained from post-embedded piezoceramic sensors on an RC column in an earthquake can be used to determine the applied force and corresponding damage or residual seismic capacity.

scholarly journals Experimental Research on Reinforced Concrete Columns Strengthened with Steel Jacket and Concrete Infill

2021 ◽  
Vol 11 (9) ◽  
pp. 4043
Author(s):  
Aleksandar Landović ◽  
Miroslav Bešević
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Experimental Research ◽  
Failure Modes ◽  
Steel Tube ◽  
Rc Columns ◽  
Rc Column ◽  
Steel Jacket ◽  
Ductile Behavior

Experimental research on axially compressed columns made from reinforced concrete (RC) and RC columns strengthened with a steel jacket and additional fill concrete is presented in this paper. A premade squared cross-section RC column was placed inside a steel tube, and then the space between the column and the tube was filled with additional concrete. A total of fourteen stub axially compressed columns, including nine strengthened specimens and five plain reinforced concrete specimens, were experimentally tested. The main parameter that was varied in the experiment was the compressive strength of the filler concrete. Three different concrete compression strength classes were used. Test results showed that all three cross-section parts (the core column, the fill, and the steel jacket) worked together in the force-carrying process through all load levels, even if only the basic RC column was loaded. The strengthened columns exhibited pronounced ductile behavior compared to the plain RC columns. The influence of the test parameters on the axial compressive strength was investigated. In addition, the specimen failure modes, strain development, and load vs. deformation relations were registered. The applicability of three different design codes to predict the axial bearing capacity of the strengthened columns was also investigated.

Seismic assessment of reinforced concrete columns with short lap splices

2021 ◽  
pp. 875529302199483
Author(s):  
Eyitayo A Opabola ◽  
Kenneth J Elwood
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Failure Modes ◽  
Concrete Columns ◽  
Seismic Assessment ◽  
Rc Columns ◽  
Lap Splices ◽  
Displacement Response ◽  
Force Displacement ◽  
Probable Failure

Existing reinforced concrete (RC) columns with short splices in older-type frame structures are prone to either a shear or bond mechanism. Experimental results have shown that the force–displacement response of columns exhibiting these failure modes are different from flexure-critical columns and typically have lower deformation capacity. This article presents a failure mode-based approach for seismic assessment of RC columns with short splices. In this approach, first, the probable failure mode of the component is evaluated. Subsequently, based on the failure mode, the force–displacement response of the component can be predicted. In this article, recommendations are proposed for evaluating the probable failure mode, elastic rotation, drift at lateral failure, and drift at axial failure for columns with short splices experiencing shear, flexure, or bond failures.

An Experiment on Seismic Shear Capacity for HRB500 Grade R/C Frame Columns within Yield Hinge Regions

2011 ◽  
Vol 105-107 ◽  
pp. 948-952
Author(s):  
Pin Wu Guan ◽  
Meng Chen
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Structural Design ◽  
Failure Modes ◽  
Seismic Loading ◽  
Concrete Columns ◽  
Shear Capacity ◽  
Reinforced Concrete Columns ◽  
Seismic Shear

An experiment on shear capacity for HRB500 grade R/C frame columns within yield hinge regions is studied. The different failure modes for specimens within yield hinge regions are classified, and the hysteretic curves are studied. The shear contributions of stirrups and concrete for columns are analyzed in detail. Based on the experimental study, formulas for the shear capacity of reinforced concrete columns are supposed under seismic loading, and the different formulas are adopted to estimate the shear capacity for columns at different seismic levels, Both security and economy of structural design are all considered.

Experimental Study on Behaviour of RC Column Confined by CFRP and Steel Fibre

2012 ◽  
Vol 446-449 ◽  
pp. 3146-3149 ◽  
Author(s):  
Xiao Xia Li
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Steel Fibre ◽  
Rc Columns ◽  
Steel Fibres ◽  
Rc Column ◽  
The Third

12 RC columns specimens are divided 4 groups which have different eccentricities. Each group has 4 specimens, The first specimen was just made of reinforced concrete. The second was wrapped with 3 lays CFRP. The third had steel fibres added to it. The last was reinforced with steel fibres and wrapped with CFRP.The results showed that the introduction of fibres as well as wrapping the specimens with FRP improve the strength of concrete,especially its ductility.

scholarly journals Experimental Quantification on the Residual Seismic Capacity of Damaged RC Column Members

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Chien-Kuo Chiu ◽  
Hsin-Fang Sung ◽  
Kai-Ning Chi ◽  
Fu-Pei Hsiao
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Failure Modes ◽  
Shear Failure ◽  
Assessment Method ◽  
Seismic Capacity ◽  
Rc Column ◽  
Damage States ◽  
Energy Dissipation Capacity ◽  
Reduction Factors

Abstract To quantify the post-earthquake residual seismic capacity of reinforced concrete (RC) column members, experimental data for 6 column specimens with flexural, flexural–shear and shear failure modes are used to derive residual seismic capacity of damaged RC column members for specified damage states in this work. Besides of the experiment data, some related researches are also investigated to suggest the reduction factors of strength, stiffness and energy dissipation capacity for damaged RC column members, respectively. According to the damage states of RC columns, their corresponding seismic reduction factors are suggested herein. Taking an RC column with the flexural–shear failure for an example, its reductions factors of strength, stiffness and energy dissipation capacity are 0.5, 0.6 and 0.1, respectively. This work also proposes the seismic performance assessment method for the residual seismic performance of earthquake-damaged RC buildings. In the case study, this work selects one actual earthquake-damaged school building to demonstrate the post-earthquake assessment of seismic performance for a damaged RC building.

scholarly journals Confinement Effect of Reinforced Concrete Columns with Rectangular and Octagon-Shaped Spirals

2020 ◽  
Vol 12 (19) ◽  
pp. 7981
Author(s):  
Hyeong-Gook Kim ◽  
Chan-Yu Jeong ◽  
Dong-Hwan Kim ◽  
Kil-Hee Kim
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Transverse Reinforcement ◽  
Longitudinal Reinforcement ◽  
Rc Columns ◽  
Rc Column ◽  
Cyclic Lateral Load ◽  
Ductility Capacity ◽  
Constant Axial Load ◽  
Spiral Type

Conventional spiral-type transverse reinforcement is effective at increasing the ductility and the maximum strength of reinforced concrete (RC) columns because it confines the inner concrete and the longitudinal reinforcement. However, when arranging crossties in a RC column with spirals, problems such as mutual interference with longitudinal reinforcement, overcrowding of reinforcement, and deterioration of constructability occur. Furthermore, the loosening of 90 and 130-degree standard hooks due to the lateral expansion of concrete causes buckling of the longitudinal reinforcement. This paper describes the ability of a newly developed spiral-type transverse reinforcement with various yield strengths to confine RC columns subjected to cyclic lateral load and constant axial load. The ductility capacity, energy dissipation, and effective stiffness of RC columns confined by the developed spiral-type transverse reinforcement were compared with those of RC columns confined by typical rectangular reinforcement. The experimental results showed that RC column specimens with the developed spiral-type transverse reinforcement have better performances in terms of ductility capacity and energy dissipation, even though the amount of reinforcement used for the specimens decreased by about 27% compared with the specimen with typical rectangular reinforcement.

scholarly journals Seismic behavior of textile-reinforced concrete–strengthened RC columns under different axial compression ratios

2019 ◽  
Vol 14 ◽  
pp. 155892501986570
Author(s):  
Liu Ming ◽  
Yin Shi-Ping ◽  
Cong Xi
Keyword(s):  
Reinforced Concrete ◽  
Axial Compression ◽  
Compression Ratio ◽  
Seismic Behavior ◽  
Peak Load ◽  
Textile Reinforced Concrete ◽  
Element Analysis ◽  
Rc Columns ◽  
Rc Column ◽  
Axial Compression Ratio

To study the effect of various axial compression ratios on the seismic behavior of reinforced concrete (RC) columns strengthened with textile-reinforced concrete, in this study, an RC column model is established using the finite element analysis software, ABAQUS. This model’s seismic performance under earthquakes is investigated, and the numerical analysis results of the two test pieces are compared with the test results to verify the correctness of the model. The results show that the initial stage of RC loading is under the three-way restraint of the axial force and textile-reinforced concrete material. The yield load and peak load of the textile-reinforced concrete–strengthened RC column increase with the increase in the axial compression ratio. However, the increase in the axial pressure during the loading process accelerates the crack development. The displacement ductility coefficient and the energy dissipation capacity of the specimen are reduced as the axial compression ratio increases. The numerical calculation results of the textile-reinforced concrete–strengthened RC column are in good agreement with the experimental results, indicating that the numerical model based on ABAQUS is reasonable.

A multi-objective optimization algorithm for Bouc–Wen–Baber–Noori model to identify reinforced concrete columns failing in different modes

2021 ◽  
pp. 146442072110200
Author(s):  
Zele Li ◽  
Mohammad Noori ◽  
Ying Zhao ◽  
Chunfeng Wan ◽  
Decheng Feng ◽  
...  
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Optimization Algorithm ◽  
Failure Modes ◽  
Concrete Columns ◽  
Multi Objective Optimization ◽  
Hysteresis Model ◽  
Restoring Force ◽  
Rc Columns ◽  
Multi Objective

Concrete columns are the most important load-bearing components in civil structures. The potential damage in reinforced concrete (RC) columns could be categorized into three different failure modes: flexural shear (FS) failure, flexural-failure (FF), and shear failure (SF). The corresponding hysteresis loops for each mode differ significantly. Therefore, a multi-parameter hysteretic restoring force model is needed to describe the hysteretic energy dissipation phenomenon and behavior. Identification of the optimal parameter values of a multi-parameter hysteresis model of RC columns under different failure modes is essential in the evaluation of structural inelastic seismic performance. In this paper, a multi-objective optimization algorithm called NSGA-II is employed to identify the parameters of Bouc–Wen–Baber–Noori model (BWBN) hysteresis model, this model has been used for describing the response and modelling restoring force behavior in several structural and mechanical engineering systems, that can fully describe the hysteretic restoring force characteristics of RC columns. An objective function for the restoring force is proposed to identify the parameters of BWBN model. In order to ensure the accuracy of identification, based on the sensitivity analysis, the parameters distribution law of RC columns in different failure modes is obtained. Furthermore, the reference values under different failure modes are proposed. The results presented in this paper will significantly reduce the calculation of subsequent identification. Twelve groups of experimental data are randomly selected to verify the feasibility of the above algorithm. It is demonstrated that using the multi-objective optimization algorithm leads to better identification accuracy with minimum prior experience. Performance of the algorithm is verified using simulated and experimental data. The experimental data of the RC columns were collected from the database of the Pacific Earthquake Engineering Research Center.

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