scholarly journals A Parameter Ascertainment Method for the Skeleton Curve of Corroded Reinforcement Concrete Members with Flexure[tnq_nbsp] and Compression

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
G. F. Chen ◽  
Y. Z. Zhang ◽  
X. J. Zhu

This paper presents an effective method of parameter ascertainment for the skeleton curve of corroded compression-bending members to establish its restoring force model. An assumption which considers the skeleton curve of damaged and undamaged members has similar shape is introduced into the fitting process of parameters. Meanwhile, two-dimensional plane section assumption is used to simplify the mathematical model and reduce the computational cost. Several sets of experimental data were compared with the prediction by the method developed in this paper, for its verification. The case studies show that the experimental trends can be captured very well.

2018 ◽  
Vol 9 (1) ◽  
pp. 103 ◽  
Author(s):  
Bin Wang ◽  
Weizeng Huang ◽  
Shansuo Zheng

In order to study the restoring force characteristics of corroded steel frame beams in an acidic atmosphere, based on different corrosion damage degrees, tests on the material properties of 48 steel samples and six steel frame beam specimens with a scale ratio of 1/2 under low cyclic repeated loading were conducted. According to the test results, the relationship between the weight loss rate and the mechanical properties of corrosion damage steel was obtained by numerical regression analysis, and the hysteresis curves and skeleton curves of the corroded steel frame beams were also obtained. The simplified trilinear skeleton curve model of the corroded steel frame beams and the expression of the corresponding feature points were determined by analyzing the failure process. The strength and stiffness degradation rule of the steel frame beam was analyzed furtherly. The hysteresis rule was established by introducing the cyclic degradation index which considers the effect of different corrosion degrees, and finally the restoring force model based on the corroded steel frame beams in an acidic atmospheric environment was established. Comparison with the test results show that the skeleton curve and the restoring force model established in this paper can accurately describe the seismic performance of corrosion damaged steel frame beams and can provide a basis for the seismic calculation analysis of corroded steel structures in an acidic atmosphere.


2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Yanhua Wang ◽  
Yan Feng ◽  
Dongsheng Huang ◽  
Zirui Huang ◽  
Zhongfan Chen

In this paper, a restoring force model, composed of a trilinear skeleton curve and hysteretic rules, is proposed based on nine pseudostatic tests of the energy-dissipation joint under horizontal low cyclic loading. The critical points of the simplified skeleton curve are obtained via theoretical derivation and FE simulation. The hysteretic rules for the joints are simplified as a concave hexagon, where the parameters of the critical points are optimized by the genetic algorithm (GA). Using the established trilinear skeleton curve, three different working stages, i.e., elastic, hardening, and softening, were divided by the critical points and the moment stiffness of three stages can be calculated. The proposed hysteretic rules of each stage can reveal and explain the “pinching” in the cyclic loading, which make it easier to understand the mechanism of the energy-dissipation joint. The comparison between the restoring force model and the tests shows that the simplified skeleton curves, the established hysteretic rules, and the ductility and the damping ratio are consistent with the experimental results. Finally, the effectiveness of the established restoring force model is verified.


2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Guifeng Zhao ◽  
Meng Zhang ◽  
Yaoliang Li ◽  
Dawang Li

A numerical simulation of the hysteresis performance of corroded reinforced concrete (RC) frame columns was conducted. Moreover, the results obtained were compared with experimental data. On this basis, a degenerated three-linearity (D-TRI) restoring force model was established which could reflect the hysteresis performance of corroded RC frame columns through theoretical analysis and data fitting. Results indicated that the hysteretic bearing capacity of frame columns decreased significantly due to corrosion of the rebar. In view of the characteristics of the hysteresis curve, the plumpness of the hysteresis loop for frame columns decreased and shrinkage increased with increasing rebar corrosion. All these illustrated that the seismic energy dissipation performance of frame columns reduced but their brittleness increased. As for the features of the skeleton curve, the trends for corroded and noncorroded members were basically consistent and roughly corresponded to the features of a trilinear equivalent model. Thereby, the existing Clough hysteresis rule can be used to establish the restoring force model applicable to corroded RC frame columns based on that of the noncorroded RC members. The calculated skeleton curve and hysteresis curve of corroded RC frame columns using the D-TRI model are closer to the experimental results.


2014 ◽  
Vol 17 (10) ◽  
pp. 1443-1457 ◽  
Author(s):  
Changqing Wang ◽  
Jianzhuang Xiao ◽  
Loan Pham ◽  
Tao Ding

The hysteresis behavior of a cast-in-situ recycled aggregate concrete (RAC) frame was analyzed based on shaking table tests on a one-fourth scaled model of a two-bay, two-span and 6-storey RAC frame. Then feature points and the stiffness degradation were defined and the deteriorating four-line-typed restoring force model was put forward. In the hysteresis model, the monotonic behavior is described by a four-line-typed skeleton curve which accounts for concrete cracking, yielding of reinforcing bars, maximum and ultimate point of the RAC frame model. The hysteresis behavior is described through a number of rules for unloading and reloading. Therefore, the restoring force model proposed in this study can capture the hysteresis response of the frame under seismic actions. Moreover, the displacement ductility of the RAC frame structure is evaluated based on the proposed restoring force model. It can be concluded from this investigation that the RAC frame structure with proper design and construction has favorable load-carrying capacity, deformation capacity, energy dissipation ability and seismic performance, and can be applied and popularized in the area with the requirement of aseismic fortification intensity.


2012 ◽  
Vol 517 ◽  
pp. 323-330
Author(s):  
Liang Bai ◽  
Tian Hua Zhou ◽  
Xing Wen Liang

Steel high performance concrete (SHPC) structural wall was a combination of steel and high performance concrete. They can give full play to the advantages of steel and high performance concrete and have better dynamic behavior. Several specimens of SHPC structural walls with different parameters were tested under constant axial loading and horizontal cyclic loading. The testing phenomena and failure mechanics of those walls were compared and analyzed. On the basis of theoretic formulas and testing data, the main characteristic points and the law of stiffness degradation were presented, then, the tri-linear and four linear restoring models were built and provided. At last, the calculation formulas of stiffness parameter in restoring force model at different stages of deformation were presented. The results show that the declined strength stage of skeleton curve of specimens is related to the yielding strain of boundary steel, axial load ratio and stirrup content. The restoring force model of SHPC structural wall is thus formed for the application of nonlinear dynamics analysis as well as static structural calculations.


2021 ◽  
Vol 11 (24) ◽  
pp. 12131
Author(s):  
Tan Wang ◽  
Ruinian Jiang ◽  
Shuaifeng Yuan ◽  
Kuo Yuan ◽  
Liwei Li ◽  
...  

Prefabricated shear walls have been widely used in engineering structures. Vertical connection joints of the walls are the key to ensure the safety of the structures. Steel–concrete composite structures have been proved to have a good bearing capacity and ductility. In this paper, a new type of prefabricated structure is proposed, in which vertical wall members are connected together through built-in steel sections and cast-in-place concrete. This paper studies the seismic performance of the proposed prefabricated concrete shear wall structure. Hysteretic curves and skeleton curves of the shear wall are obtained based on experimental analyses. A dimensionless skeleton curve model is developed using the theory of material mechanics and the method of regression analysis. A stiffness calculation method for different loading stages is obtained and a restoring force model is proposed. The proposed innovative prefabricated shear wall structure provides good resistance to seismic performance and the related analysis provides a fundamental reference for studies of prefabricated shear wall structures.


2018 ◽  
Vol 21 (13) ◽  
pp. 2018-2029
Author(s):  
Xide Zhang ◽  
Zhiheng Deng ◽  
Xiaofang Deng ◽  
Jingwei Ying ◽  
Tao Yang ◽  
...  

To evaluate the ductility and energy dissipation capacity of the beam with concrete-encased steel truss, eight specimens with different types of steel truss, reinforcement ratios, and shear span ratios were tested by low-cyclic loading regime. The results indicated that beams with concrete-encased steel truss performed plumped load–displacement hysteretic loops as well as high strength and stiffness. Moreover, cross-web members improved their seismic behavior more effectively than non-cross-web members. Finally, the restoring force model of concrete-encased steel truss beam is proposed in accordance with the experimental results, which can be used to predict the load–displacement behavior of concrete-encased steel truss beam. The results could also provide a reference for the design and application of concrete-encased steel truss beam in practice.


2012 ◽  
Vol 271-272 ◽  
pp. 186-189 ◽  
Author(s):  
Feng Li Cao ◽  
Hong Bai Bai ◽  
Zhong Bo He ◽  
Guo Quan Ren

Dynamic load experiments of the disc-shaped metal rubber isolation component are performed. Through analyzing variation law of the parameters with amplitude and frequency, which are stiffness coefficient, damping coefficient and damping component factor, the hysteresis restoring force model which is able to fully reveal the dynamic characteristics of the component is established. The experimental verification results show that the theoretic calculations are consistent with the experimental data, which verifies the practicability and effectiveness of mathematical model and parameter identification. It has important practical significance for design of vibration isolation component with different requirements.


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