scholarly journals NUMERICAL EVALUATION OF LOAD-CARRYING MECHANISMS OF RC COLUMNS BASED ON DAMAGE OF CONSTITUTIVE MATERIALS

Author(s):  
Takeshi MAKI ◽  
Satoshi TSUCHIYA ◽  
Shigehiko SAITO ◽  
Tadatomo WATANABE
2013 ◽  
Vol 671-674 ◽  
pp. 1319-1323
Author(s):  
Zi Xue Lei ◽  
Yu Hang Han ◽  
San Sheng Dong ◽  
Jun Qing Guo

A centrally reinforced column is a new type of RC columns, formed by providing a reinforcement skeleton at the central part of the cross section of an ordinary RC column. Tests have shown that as compared with an ordinary RC column, this type of columns has a higher load carrying capacity and ductility. From the pushover analysis of a frame composed of ordinary RC columns and one consisting of centrally reinforced columns, their seismic performance under seismic load of 9-degree intensity was studied according to Chinese code, including target displacements, story-level displacements, interstory drifts, appearance and development of plastic hinges. The results indicate that although the dimensions of cross sections of columns in the frame with centrally reinforced columns are smaller than those of the ordinary frame, the former still has a higher overall load carrying capacity and seismic performance than the latter.


2018 ◽  
Vol 22 (7) ◽  
pp. 1554-1565 ◽  
Author(s):  
Jianwei Tu ◽  
Kui Gao ◽  
Lang He ◽  
Xinping Li

At present, extensive studies have been conducted relative to the topic of fiber-reinforced polymer(FRP)- reinforced concrete (RC) flexural members, and many design methods have also been introduced. There have, however, been few studies conducted on the topic of FRP-RC compression members. In light of this, eight glass-fiber-reinforced polymer (GFRP)-RC square columns (200×200×600 mm) were tested in order to investigate their axial compression performance. These columns were reinforced with GFRP longitudinal reinforcement and confined GFRP stirrup. These experiments investigated the effects of the longitudinal reinforcement ratio, stirrup configuration (spirals versus hoops) and spacing on the load-carrying capacity and failure modes of GFRP-RC rectangular columns. The test results indicate that the load-carrying capacity of longitudinal GFRP bars accounted for 3%-7% of the ultimate load-carrying capacity of the columns. The ultimate load-carrying capacity of RC columns confined with GFRP spirals increased by 0.8%-1.6% with higher ductility, compared to GFRP hoops. Reducing the stirrup spacing may prevent the buckling failure of the longitudinal bars and increase the ductility and load-carrying capacity of the GFRP-RC columns. It has been found that setting the GFRP compressive strength to 35% of the GFRP maximum tensile strength yields a reasonable estimate of ultimate load-carrying capacity of GFRP-RC columns.


2017 ◽  
Vol 153 ◽  
pp. 264-278 ◽  
Author(s):  
Fabio Di Carlo ◽  
Alberto Meda ◽  
Zila Rinaldi

2021 ◽  
Vol 245 ◽  
pp. 112836
Author(s):  
Abdoulaye Sanni Bakouregui ◽  
Hamdy M. Mohamed ◽  
Ammar Yahia ◽  
Brahim Benmokrane

In this paper, 1 group of plain concrete square columns 150×150×600 mm and 11 groups of concrete columns reinforced with glass fiber reinforced polymer (GFRP) were cast and tested, each group contains of 3 specimens. These experiments investigated effect of the main reinforcement ratio, stirrup spacing and contribution of longitudinal GFRP bars on the load carrying capacity of GFRP reinforced concrete (RC) columns. Based on the experiment results, the relationship between load-capacity and reinforcement ratio and the plot of contribution of longitudinal GFRP bars to load-capacity versus the reinforcement ratio were built and analyzed. By increasing the reinforcement ratio from 0.36% to 3.24%, the average ultimate strain in columns at maximum load increases from 2.64% to 75.6% and the load-carrying capacity of GFRP RC columns increases from 3.4% to 25.7% in comparison with the average values of plain concrete columns. Within the investigated range of reinforcement ratio, the longitudinal GFRP bars contributed about 0.72%-6.71% of the ultimate load-carrying capacity of the GFRP RC columns. Meanwhile, with the same configuration of reinforcement, contribution of GFRP bars to load-carrying capacity of GFRP RC columns decreases when increasing the concrete strength. The influence of tie spacing on load-carrying capacity of reinforced columns was also taken into consideration. Additionally, experimental results allow us to propose some modifications on the existing formulas to determine the bearing capacity of the GFRP RC column according to the compressive strength of concrete and GFRP bars.


2006 ◽  
Vol 128 (3) ◽  
pp. 486-492 ◽  
Author(s):  
Marilena Glovnea ◽  
Emanuel Diaconescu

Machine design and electrical contacts involve frequently elastic circular contacts subjected to normal loads. Depending on geometry, these may be Hertzian or surface contacts. Both possess highly nonuniform pressure distributions which diminish contact load carrying capacity. The achievement of a uniform pressure distribution would be ideal to improve the situation, but this violates stress continuity. Instead, the generation of a uniform pressure over most of contact area can be sought. Generally, equivalent punch profile which generates this pressure is found by numerical evaluation of double integrals. This paper simplifies the derivation of punch profile by using an existing correspondence between a polynomial punch surface and elastically generated pressure. First, an improved pressure profile is proposed seeking to avoid high Huber-Mises-Hencky stresses near contact surface. Then, this is approximated by the product between typical Hertz square root and an even polynomial, which yields directly the punch profile. Formulas for normal approach and central pressure are derived.


2013 ◽  
Vol 8-9 ◽  
pp. 343-352
Author(s):  
Ionut Ovidiu Toma ◽  
Daniel Covatariu ◽  
Irina Lungu ◽  
Mihai Budescu

Numerical simulations based on the Finite Element Method (FEM) have become an important tool in studying various phenomena of interest to both researchers and practitioners alike. The recent advances in computational power coupled with accurate mathematical models have made FEM an indispensable tool for investigating complex loading states and material behavior that are frequently met in civil engineering. Strengthening of existing RC columns is becoming a pressing issue in the field of civil engineering due to the necessity of meeting new safety requirements for the buildings located in active seismic areas. Jacketing is a widely used method for strengthening of reinforced concrete columns showing good results in terms of increased strength and stiffness but with the addition of some unwanted effects amongst which the added dead weight is of primary importance in case of an earthquake. The paper presents the results obtained by means of Finite Element Analysis (FEA) on the load carrying capacity of short RC columns strengthened with a novel Cementitious material that may be the solution to lighter structures and lower added costs compared to other existing methods.


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