scholarly journals Damage control of a twin-column pier with a replaceable steel shear link in a cap beam under transverse seismic motion

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Weiting Chen ◽  
Xuemeng Bai ◽  
Tengfei Xu ◽  
Shanshan Ke ◽  
Kailai Deng ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Damage Control ◽  
Damping Ratio ◽  
Compressive Strain ◽  
Nonlinear Dynamic Analysis ◽  
Compressive Load ◽  
Reinforced Concrete Column ◽  
Structural Dynamic ◽  
Shear Link

AbstractThis paper proposes a novel twin-column pier with a steel shear link (SSL) installed in the cap beam to reduce seismic damage in the transverse direction. The SSL interrupts the rigid cap beam and relieves the coupled deformation of the two columns. Benefits of the yieldable SSL in the event of a strong earthquake are the longer effective deformation of a column and limited axial compressive load. A benchmark reinforced-concrete bridge is employed in a seismic performance evaluation to verify the damage reduction performance of the novel twin-column pier with an SSL. Five numerical models, calibrated in a physical component test, are built in ABAQUS; that is, one original bridge and four novel bridges with different SSLs and accompanying configurations. Modal analysis shows that introducing the SSL does not change the overall structural dynamic characteristics. The nonlinear dynamic analysis results indicate that adopting the SSL effectively reduces the peak compressive strain of the reinforced-concrete column, but energy dissipation from the SSL is negligible compared with the total inputted seismic energy. There is no evident change in the macro seismic response of the twin-column pier when using the SSL, such as overall drift and structural damping ratio. Moreover, a transverse continuous main girder is suggested for realizing an additional restoring moment at the column top, which further reduces compressive strain.

Research on Damage Status of the Reinforced Concrete Ground Floor Columns

2012 ◽  
Vol 226-228 ◽  
pp. 1436-1440
Author(s):  
Li Jun Gao ◽  
Yong Sheng Zhang ◽  
Qin Li
Keyword(s):  
Reinforced Concrete ◽  
Measurement Method ◽  
Damping Ratio ◽  
Simple Calculation ◽  
Dynamic Measurement ◽  
Concrete Column ◽  
Destructive Testing ◽  
Reinforced Concrete Column ◽  
First Order ◽  
Vibration Model

In this paper, dynamic measurement method is applied to test the damage of the bottom reinforced concrete column. The comparison between the calculated first order frequency of the bottom reinforced concrete column and the measured first order frequency shows that the result is consistent. This indicates that this approach is feasible. However, in recent years, dynamic measurement method is widely used in non-destructive testing of bridges and floors. The principle of the dynamic measurement method for the detection of reinforced concrete column utilizes the measured natural frequency, vibration model and damping ratio of reinforced concrete column and such inherent dynamic characteristics of indicators to reflect the damage of reinforced concrete column. And there is no secondary injury for the column. The simplified method of structure dynamics is applied to calculate the frequency of the bottom reinforced concrete column. And the simple calculation method is verified by experiment and practice.

scholarly journals Applications of a LITS semi-empirical model in plain and reinforced concrete members subjected to a uniaxial compressive load

2017 ◽  
Vol 10 (2) ◽  
pp. 317-332
Author(s):  
T. E. T. BUTTIGNOL
Keyword(s):  
Reinforced Concrete ◽  
Empirical Model ◽  
High Performance ◽  
Thermal Strain ◽  
Compressive Load ◽  
High Strength ◽  
Reinforced Concrete Column ◽  
Practical Applications ◽  
Concrete Members ◽  
Semi Empirical

Abstract This paper describes a LITS (Load Induced Thermal Strain) semi empirical model and two practical applications in simple and reinforced concrete members. The model allows a preliminary and straightforward quantification of the total strain of concrete structures submitted to heating and a sustained compressive load, without the need to use complex numerical analyses. The model takes into account the effect of the thermal expansion restraint due to the boundary conditions (temperature and compressive load) and can be adopted for several types of concretes (conventional, high strength and ultra high performance). In the first example, the total deformations of simple concrete specimens from KHOURY (2006) are determined. In the second example, the total displacement of a reinforced concrete column from SCHNEIDER et al (1994) is calculated. A comparison between the results of the model and the experimental values demonstrated the reliability of the semi-empirical model to obtain a preliminary quantification of the total deformations of concrete.

scholarly journals Analysis of damping ratio on the optimization of geometrically nonlinear truss structures subjected to dynamic loading

2020 ◽  
Vol 19 (3) ◽  
pp. 321-334
Author(s):  
Élcio Cassimiro Alves ◽  
◽  
Larissa Bastos Martinelli ◽  
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Loading ◽  
Geometric Nonlinearity ◽  
Numerical Models ◽  
Damping Ratio ◽  
Nonlinear Dynamic Analysis ◽  
Truss Structures ◽  
Geometrically Nonlinear ◽  
Cross Sectional ◽  
Updated Lagrangian

The objective of this paper is to present the formulation for optimizing truss structures with geometric nonlinearity under dynamic loads, provide pertinent case studies and investigate the influence of damping on the final result. The type of optimization studied herein aims to determine the cross-sectional areas that will minimize the weight of a given structural system, by imposing constraints on nodal displacements and axial stresses. The analyses are carried out using Sequential Quadratic Programming (SQP), available in MATLAB’s Optimization Toolbox™. The nonlinear finite space truss element is defined with an updated Lagrangian formulation, and the geometrically nonlinear dynamic analysis performed herein combines the Newmark method with Newton-Raphson iterations. The dynamic analysis approach was validated by comparing the results obtained with solutions available in the literature as well as with numerical models developed with ANSYS® 18.2. A number of optimization examples of planar and space trusses under dynamic loading with geometric nonlinearity are presented. Results indicate that the consideration of damping effects may lead to a significant reduction in structural weight and that such weight reduction is proportional to increases in damping ratio.

Experimental Research on Eccentric Compressive Performance of Steel Tube-Reinforced Concrete Column

2010 ◽  
Vol 163-167 ◽  
pp. 184-190
Author(s):  
Quan Quan Guo ◽  
Yu Xi Zhao ◽  
Kun Shang
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Compressive Load ◽  
Concrete Columns ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Displacement Curve ◽  
Concrete Column ◽  
Reinforced Concrete Column ◽  
Reinforced Concrete Columns

Eccentric loading experiment of 13 steel tube-reinforced concrete columns and a reinforced concrete column is implemented. The whole process from the start load on the steel tube-reinforced concrete column until damage has been researched. Change of ultimate bearing capacity with eccentricity, longitudinal reinforcement ratio, position coefficient has been studied, and deflection curve and load-vertical displacement curve under eccentric compressive load were obtained. Failure characteristics of steel tube-reinforced concrete were divided into two different type, small eccentric damage and big eccentric damage. With the same conditions, when steel tube ratio of steel tube-reinforced concrete was 2%, its ultimate bearing capacity was nearly double of reinforced concrete columns.

Experimental Study on the Effect of Moisture Content on Hysteretic Behavior of Reinforced Concrete Columns

2018 ◽  
Vol 12 (1) ◽  
pp. 47-61
Author(s):  
Wenjuan Lv ◽  
Baodong Liu ◽  
Ming Li ◽  
Lin Li ◽  
Pengyuan Zhang
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Moisture Content ◽  
Early Stage ◽  
Damping Ratio ◽  
Concrete Columns ◽  
Hysteretic Behavior ◽  
Cyclic Test ◽  
Experimental Result ◽  
Reinforced Concrete Columns

Background: For reinforced concrete structures under different humid conditions, the mechanical properties of concrete are significantly affected by the moisture content, which may result in a great change of the functional performance and bearing capacity. Objective: This paper presents an experiment to investigate the influence of the moisture content on the dynamic characteristics and hysteretic behavior of reinforced concrete column. Results: The results show that the natural frequency of reinforced concrete columns increases quickly at an early stage of immersion, but there is little change when the columns are close to saturation; the difference between the natural frequencies before and after cyclic test grows as the moisture content rises. The damping ratio slightly decreases first and then increases with the increase of moisture content; the damping ratio after the cyclic test is larger than before the test due to the development of the micro-cracks. Conclusion: The trend of energy dissipation is on the rise with increasing moisture content, although at an early stage, it decreases slightly. According to the experimental result, a formula for the moisture content on the average energy dissipation of reinforced concrete columns is proposed.

scholarly journals Calibrating a New Constitutive Tension Model to Extract a Simplified Nonlinear Sectional Analysis of Reinforced Concrete Beams

2021 ◽  
Vol 11 (5) ◽  
pp. 2292
Author(s):  
Alaaeldin Abouelleil ◽  
Hayder A. Rasheed
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Compressive Strain ◽  
Design Criterion ◽  
Reinforced Concrete Beams ◽  
Secondary Outcome ◽  
Shear Stresses ◽  
Structural Members ◽  
Flexural Member ◽  
Smeared Crack

Nonlinear analysis of structural members is vital to understand the behavior and the response of reinforced concrete members. Even though most design procedures concentrate on the ultimate stage of response towards the end of the post-yielding zone as the decisive design criterion, the structural members usually function at the service load levels within the post-cracking zone. Therefore, cracking is a critical aspect of concrete behavior that affects the overall response of reinforced concrete beams. The initiation and the propagation of the cracks are affected directly by the tension and shear stresses in the beam. In flexural beams, the tensile stresses dominate the crack onset and its growth. Cracks in reinforced concrete flexural beams leave non-cracked regions in between the cracked sections. In order to apply a consistent analysis strategy, the smeared crack approach averages the behavior of these different cracked sections and uncracked in between regions to generate an accurate global response of the entire beam. This study presents a numerical constitutive tensile model that captures the complete tensile response of the reinforced concrete flexural member, in terms of averaged/smeared crack response. As a second step, this model was examined against a large pool of experimental data to validate its accuracy. Overall, the main objective of this study is to develop a representative constitutive tensile model for reinforced concrete flexural members and validate its accuracy against experimental results. The full nonlinear sectional response is analytically realized, based on the assumed trilinear moment–curvature response and the assumed trilinear moment–extreme fiber compressive strain response. This is considered as the secondary outcome of the present study.

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