Research on Skeleton Curve of CFST Frame Structure

2012 ◽  
Vol 204-208 ◽  
pp. 813-816
Author(s):  
Xiu Li Sun

Concrete filled steel tubular (CFST) structure is a new type of structure. According to unified theory, hysteretic model of steel beam, reinforced concrete beam and CFST column have been chosen respectively, then nonlinear structural analysis program called IDARC is employed to determine skeleton curve of the CFST frame structure. Results obtained from program are consistent well with those obtained from experiments. Furthermore, some parameters that affect the restoring force model of CFST structure have been studied, including axial compression ratio, steel ratio, material strength and so on. The results not only provide necessary theory basis for popularizing the CFST structure but play a valuable role to seismic design of CFST structure. The contribution described herein outlines a possibility for simulating the seismic behavior of CFST using the nonlinear program called IDARC. The present work offers a simplified approach for establishing the skeleton curves of CFST frames.

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yan Dai ◽  
Shaofeng Nie ◽  
Tianhua Zhou ◽  
Yichun Xu ◽  
Jingrong Peng

In this paper, two joints of circular tubed steel-reinforced concrete (CTSRC) column were designed. The load-displacement hysteretic curve and skeleton curve of this new type of joint are obtained by the pseudostatic test under low cycle cyclic load on the top of the column. The results show that this new type of joint has good seismic energy dissipation performance. On the basis of the test, a three-fold skeleton curve model considering three characteristic points of yield, limit, and failure is proposed, and the expression of skeleton curve model is given. The load and unload stiffness degradation law of specimens under reciprocating load is studied, and the expression of stiffness degradation law is given. The hysteresis law of the new type joint specimens is described in detail. The validity of the model is verified by comparing the experimental curve with the model curve. The model can be used in the elastic-plastic seismic time-history analysis on the joint of circular tubed steel-reinforced concrete (CTSRC) column.


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 594-597 ◽  
pp. 886-890 ◽  
Author(s):  
Gan Hong ◽  
Mei Li ◽  
Yi Zhen Yang

Abstract. In the paper, take full account of energy dissipation operating characteristics. Interlayer shear-frame structure for the analysis of the Wilson-Θmethod ELASTOPLASTIC schedule, the design of a nonlinear dynamic time history analysis procedure. On this basis, taking into account the restoring force characteristics of the energy dissipation system, the inflection point in the restoring force model treatment, to avoid a result of the calculation results of distortion due to the iterative error. A frame structure seismic response time history analysis results show that: the framework of the energy dissipation significantly lower than the seismic response of the common framework, and its role in the earthquake when more significant.


2014 ◽  
Vol 578-579 ◽  
pp. 252-255
Author(s):  
Ya Feng Xu ◽  
Qian Chen ◽  
Pi Yuan Xu ◽  
Riyad S. Aboutaha

Composite concrete filled steel tubular (CFST) column is a new type of column having high ductility and high load-bearing capacity. In this paper, the finite element analysis software ABAQUS is used to study the seismic performance of 3D joint of composite CFST column and steel beam. The hysteretic curve and skeleton curve are obtained by changing the strength grade of the steel beam; calculate the energy dissipation ratio of the joint. The results show that the higher the beam’s steel strength the higher ultimate capacity of the joint in the constant axial load. But the full degree of hysteresis curve, energy dissipation and displacement ductility of the space joint decrease.


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.


2005 ◽  
Vol 11 (9) ◽  
pp. 1147-1158 ◽  
Author(s):  
G. Michon ◽  
L. Manin ◽  
R. Dufour

In this paper we describe the modeling of the hysteretic behavior of belt tensioners. An initial experimental device is composed only of the tensioner by using forcing frequencies, preloads and deflection amplitudes. It permits the identification of the parameters of the restoring force model used. Comparison of the measured and predicted force-deflection loops of the tensioner subjected to large deflections permits preliminary validation of the model. The second experimental device consists of a belt-tensioner system. Its non-linear modeling includes the above hysteretic model and the belt’s longitudinal characteristics. Validation of the belt-tensioner model is completed by comparing the measured and predicted belt tension. Finally, it is shown by using a parametric investigation and phase-plane portrait that the response of the belt-tensioner system increases with the frequency and the amplitude of the excitation.


2011 ◽  
Vol 250-253 ◽  
pp. 2749-2753
Author(s):  
Ling Xin Zhang ◽  
Ping Chuan Wu ◽  
Gui Hong Ni

The study on the hysteretic characteristics of steel reinforced concrete (SRC) members is the basis of nonlinear seismic analysis of such structures. So in this paper, by summarizing the hysteretic features of SRC members, a quadrant-linear restoring-force model is suggested. Then the model is verified with available experimental results and proved to be effective and reliable.


2014 ◽  
Vol 638-640 ◽  
pp. 224-227
Author(s):  
Hua Ma ◽  
Fang Liang Zhang ◽  
Zhen Bao Li ◽  
Diane Amba Mfinda ◽  
Han Jie Li

A new type buckling restrained brace ensuring to work under different levels of earthquakes is analyzed in this paper. The brace is simplified by LINK elements of SAP2000. The skeleton curve of the mode is clarified. Three specimens with different slot widths are designed to evaluate the simplified model used in the software SAP2000. The evaluation work is accomplished through the software ABAQUS. The force mechanism, the hysteretic model and proposed reasonable scopes of slot widths are grasped. The numerical simulation work proves that the new type buckling restrained brace performs excellently.


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.


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