scholarly journals Seismic Failure Modes and Deformation Capacity of Reinforced Concrete Columns under Cyclic Loads

2017 ◽  
Vol 62 (1) ◽  
pp. 80-91 ◽  
Author(s):  
Ma Ying ◽  
Gong Jin-xin

This paper investigates the seismic failure modes and horizontal deformation capacity of reinforced concrete square columns based on the pseudo-static test. The controlled variables include shear aspect ratio, axial load ratio and stirrup spacing. The seismic failure modes, the inelastic deformation capacity after yielding and the deformation components due to flexure, shear and anchorage slip of the RC columns were analyzed, especially flexural-shear failure. The results show that decreasing shear aspect ratio, or increasing axial load or stirrup spacing can result in the change of column failure mode from flexural failure to flexural- shear failure or shear failure, the pinching of hysteresis loops, the reductions of hysteresis loop area and deformation capacity. With the increase of total displacement, all three displacement components increased; the contribution of flexure displacement in total displacement reduced, the contribution of shear displacement increased, the contribution of anchorage slip displacement changed in the range of 30%- 40%.

2015 ◽  
Vol 37 ◽  
pp. 247 ◽  
Author(s):  
Hooman Farahmand ◽  
Mohammad Reza Azadi Kakavand ◽  
Shahriar Tavousi Tafreshi ◽  
Pooria Hafiz Hafiz

Experimental research activities and post-earthquake considerations have demonstrated that reinforcedconcrete columns with light or widely spaced transverse reinforcement are vulnerable to shear failure duringearthquakes. According to this point by using failure limit curve, we can assess the effective parameters in shearand axial failure of reinforced concrete columns in framed buildings. In the current study by flexural, shear andaxial springs which are used in series, shear and axial failures and important effective parameters have beenassessed, Besides 5,10 and 15 story models with different amounts of initial axial load ratio have been analyzedby nonlinear push-over analysis. The results of analytical models contain behavior of buildings based on differentinitial axial load ratio and different spacing of transverse reinforcement are compared


2013 ◽  
Vol 351-352 ◽  
pp. 1450-1453
Author(s):  
Xiao Yong Wu ◽  
Yang Zhou Li

The elasto-plastic analysis of reinforced concrete square columns was introduced to study the relationship between lateral force and curvature by using the open source program OpenSees. A pseudo static test on the inverted "T" shape reinforced concrete square column was conducted for the comparative analysis. The results indicated that the lateral force calculated by program agree with experimental data with an axial load ratio of 0.33. The calculated yield lateral force was 29.7 kN, the error was lower than 7% compared with experimental results. In addition, the cross-section curvature were obtained, which were difficult to obtain through the traditional experimental study, the calculated yield curvature was 1.825×10-5. The calculated results with different axial load ratios were presented in this paper, which showed that both the yield lateral force and curvature of reinforced concrete square columns were increased with low axial load ratio, and at the same time it could reduce some experimental work by using computer simulation.


2021 ◽  
pp. 136943322110073
Author(s):  
Yu Cheng ◽  
Yuanlong Yang ◽  
Binyang Li ◽  
Jiepeng Liu

To investigate the seismic behavior of joint between special-shaped concrete-filled steel tubular (CFST) column and H-section steel beam, a pseudo-static test was carried out on five specimens with scale ratio of 1:2. The investigated factors include stiffening types of steel tube (multi-cell and tensile bar) and connection types (exterior diaphragm and vertical rib). The failure modes, hysteresis curves, skeleton curves, stress distribution, and joint shear deformation of specimens were analyzed to investigate the seismic behaviors of joints. The test results showed the connections of exterior diaphragm and vertical rib have good seismic behavior and can be identified as rigid joint in the frames with bracing system according to Eurocode 3. The joint of special-shaped column with tensile bars have better seismic performance by using through vertical rib connection. Furthermore, a finite element model was established and a parametric analysis with the finite element model was conducted to investigate the influences of following parameters on the joint stiffness: width-to-thickness ratio of column steel tube, beam-to-column linear stiffness ratio, vertical rib dimensions, and axial load ratio of column. Lastly, preliminary design suggestions were proposed.


2022 ◽  
pp. 1-24
Author(s):  
Dimitrios K. Zimos ◽  
Panagiotis E. Mergos ◽  
Vassilis K. Papanikolaou ◽  
Andreas J. Kappos

Older existing reinforced concrete (R/C) frame structures often contain shear-dominated vertical structural elements, which can experience loss of axial load-bearing capacity after a shear failure, hence initiating progressive collapse. An experimental investigation previously reported by the authors focused on the effect of increasing compressive axial load on the non-linear post-peak lateral response of shear, and flexure-shear, critical R/C columns. These results and findings are used here to verify key assumptions of a finite element model previously proposed by the authors, which is able to capture the full-range response of shear-dominated R/C columns up to the onset of axial failure. Additionally, numerically predicted responses using the proposed model are compared with the experimental ones of the tested column specimens under increasing axial load. Not only global, but also local response quantities are examined, which are difficult to capture in a phenomenological beam-column model. These comparisons also provide an opportunity for an independent verification of the predictive capabilities of the model, because these specimens were not part of the initial database that was used to develop it.


2011 ◽  
Vol 243-249 ◽  
pp. 149-155 ◽  
Author(s):  
Zhe Li ◽  
Shao Ji Chen ◽  
Ye Ni Wang ◽  
Cui Ping Zhang ◽  
Jing Xu

The neutral axis change along with axial load ratio, load angle, section size etc. For the neutral axis of SRCLSC(steel reinforced concrete L-shaped column) is neither plumb with the plane that the moment work on, nor parallel with borderlines of SRCLSC section, it is difficult to get loading capacity and ductility of SRCLSC on biaxial eccentric loading. Based on the plane-section assumption, a method for the nonlinear analysis of complete response process for ductility of 15 SRCLSC..It include 36 sets for load angle, 6 sets for axial load ratio, 3 sets for concrete strength, 3 sets for the content of steel, 2 sets for steel style, 3 sets for stirrup ratio, 3 sets for steel location, 3 sets for section size, 3 sets for stirrup diameter about SRCLSC. The ductile behavior of L-shaped, with calculating 1068 loading conditions,are investigated. It concluded that axial load ratio, load angle, and ratio of the spacing of stirrups and longitudinal reinforcement’s diameter (s/d) are most important factors.


2015 ◽  
Vol 730 ◽  
pp. 81-84
Author(s):  
Huan Jin

Based on the quasi-static test of single-layer, two-bay RC frame model, using DIANA finite element program, a finite element Macro-model of masonry-infilled frame structure was established, and nonlinear finite element analysis of frame structures filled with different masonry materials was conducted. As a result of the existence of infill walls, the failure modes of frame structure have been changed, and which is easy to cause shear failure at the top of frame columns. If masonry materials of infill walls are different, the effects of infill panels on frame structures will be different. Comparative analysis shows that the influence of clay bricks is the largest, followed by autoclaved bricks’ influence, while aerated concrete blocks’ influence is the smallest. Therefore, to avoid the associated failure mechanism caused by infill walls, lightweight masonry materials are suggested to be used in actual engineering.


2013 ◽  
Vol 357-360 ◽  
pp. 699-704 ◽  
Author(s):  
Guang Yang ◽  
Zuo Zhou Zhao ◽  
Xiao Gang He

To study the biaxial strength and failure characteristics of reinforced concrete in the state of biaxial tension-compression stresses and provide some suggestions for the practical engineering design, 3 one-third scale reinforced concrete (RC) plate specimens are tested. The results indicate that, in biaxial tension-compression stresses, reinforced concrete cracks in the direction normal to the principal tensile stress direction and presents the characteristics of shear failure modes. The test device could simulate the required stress condition. The compression strength of reinforced concrete is obviously lower than the uniaxial strength fc. The reduction factor k is about 0.55~0.75 which varies with different tension-compression force ratio. Concrete material takes part in the tension process of reinforced concrete and shares part of the tension, while the share ratio decreases as concrete cracks gradually.


2010 ◽  
Vol 163-167 ◽  
pp. 1540-1546
Author(s):  
Liang Bai ◽  
Tian Hua Zhou ◽  
Xing Wen Liang

The cyclic loading test of three steel high performance concrete(SHPC) structural walls was conducted and the failure pattern of the structural walls under the combined effect of axial force, bending moment, and shear force was researched. Based on the experimental results, the displacement-based deformation capacity design method was proposed for SHPC structural walls. It is obtained for the interrelated relationships among the ultimate drift ratio, the axial load ratio, the characteristic value of stirrup content and the aspect ratio. It is concluded that the increasing the characteristic value of stirrup content and limiting the axial load ratio were effective means to improve ductility. The characteristic value of stirrup content of SHPC structural walls with different ultimate drift ratio and axial load ratio were proposed and the conclusion can be referred by the design of SHPC structural walls.


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