scholarly journals Determination of stiffness reduction factor for U-shaped reinforced concrete shear walls under bi-axial loading

2016 ◽  
Author(s):  
Sai Krishna Yemmaleni
Keyword(s):  
Reinforced Concrete ◽  
Axial Loading ◽  
Shear Walls ◽  
Reduction Factor ◽  
Stiffness Reduction

scholarly journals Shear walls of limited ductility

1980 ◽  
Vol 13 (2) ◽  
pp. 144-161
Author(s):  
L. M. Robinson
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Design Method ◽  
Shear Walls ◽  
Strength Design ◽  
Earthquake Resistant ◽  
Heavy Damage ◽  
Suggested Classification ◽  
Classification And Treatment

The design and detailing of earthquake resistant reinforced concrete shear walls of limited ductility designed by a modified strength design method are discussed. Suitable methods for the evaluation of actions and the determination of internal actions
are advanced, having regard to energy dissipation and the consequences of heavy damage or of collapse. Discussion is not restricted to uniform walls, but is extended to walls with openings, for which a suggested classification and treatment is presented, thus allowing for suitable design techniques for walls transitional between uniform walls and frames to be determined. Applications 
of the proposals are illustrated in an Appendix.

Cell Network-Based Formulas for Fast Determination of Flexural Stiffness Reduction of U-Shaped Core Shear Walls

2018 ◽  
Vol 34 (2) ◽  
pp. 867-891
Author(s):  
Yicheng Yang ◽  
Sai Yemmaleni ◽  
Ikkyun Song ◽  
In Ho Cho
Keyword(s):  
Shear Walls ◽  
Shear Wall ◽  
Flexural Stiffness ◽  
Finite Element Analyses ◽  
Efficient Tool ◽  
Fast Determination ◽  
Cell Network ◽  
Stiffness Reduction ◽  
Unit Cells

Reinforced concrete (RC) core shear wall is one of the most widely used earthquake-resisting systems. Degradation of a core wall's flexural stiffness is vital for understanding the natural frequency shift of the damaged building. But it is hard to capture, often necessitating complex finite element analyses (FEAs). This study seeks to provide an efficient tool to quickly determine the remaining flexural stiffness of U-shaped core walls. Importantly, the tool is designed to require only the easy-to-collect observational damage information. Of primary novelty is a network of microscopic unit cells, each consisting of nonlinear concrete and steel springs along with a compression-only gap. Validations with three U-shaped walls tested under complex and multidirectional loading paths show that the proposed formulas appear promising in quickly determining the trend of degrading flexural stiffness compared with a high-precision multiscale FEA program. All the formulas written in Matlab codes are made publicly available. Using the portable formulas running on a laptop, practicing engineers and researchers will be able to swiftly diagnose core U-shaped walls after quick on-site or laboratory observations.

Study on Flexural Stiffness Reduction Factor of Reinforced Concrete Column with Equiaxial T Shaped Section

2013 ◽  
Vol 351-352 ◽  
pp. 319-324
Author(s):  
Xiu Ling Feng ◽  
Meng Shen ◽  
Xiang Ya Kong ◽  
Jie Zhang ◽  
Peng Fei Luo
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structure ◽  
Geometrical Nonlinearity ◽  
The United States ◽  
Reduction Factor ◽  
Material Nonlinearity ◽  
Flexural Stiffness ◽  
Stiffness Reduction ◽  
Stiffness Method ◽  
Shaped Section

The reduced stiffness method had been adopted to evaluate the material nonlinearity characteristics of reinforced concrete structures to be in compliance with concrete structure standards of the United States, New Zealand and Canada. Concrete structure design code in China also accepts the reduced stiffness method as a supplementary method of considering the second-order effects problem. However, the concrete structure with specially shaped columns code of China still use amplified coefficients of eccentricity to consider nonlinearity characteristics of reinforced concrete structure with special shaped columns. Based on the numerical integral method, a flexural stiffness reduction factor is proposed to consider characteristics of material nonlinearity and geometrical nonlinearity of reinforced concrete columns with equiaxial T shaped section.

scholarly journals Relationship between Corrosion of Reinforcement and Surface Cracking Width in Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Jian Cao ◽  
Liangfang Liu ◽  
Shangchuan Zhao
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Surface Crack ◽  
Crack Width ◽  
Limit State ◽  
Steel Corrosion ◽  
Reduction Factor ◽  
Surface Cracking ◽  
Stiffness Reduction ◽  
Experimental Values

The durability of structure cannot be guaranteed when a corrosion expansion crack reaches the surface of the reinforced concrete member. In this paper, firstly, based on the existing theoretical model of steel corrosion degree, the calculation process of the model and the determination of the relevant parameters in the model were analyzed and discussed. Secondly, the stiffness reduction factor of concrete in the model was calculated according to the existing experimental data, and the engineering formula of the steel corrosion degree was established, which was related to the surface crack width of reinforced concrete. Moreover, the experiments of steel bar corrosion were carried out with different components of surface crack width, in which the parameters of the bar diameter, concrete protection layer thickness, and water-cement ratio were taken into consideration. The experimental phenomena and results were further analyzed and discussed. Finally, comparing with the experimental data, the engineering formula presented in the paper was validated. The results show that the calculated values by the engineering formula are in better agreement with the experimental values than those by the existing model, which provide a theoretical basis for further study on the durability limit state of the structure.

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