scholarly journals Effect of the connecting beam stiffness on the bracing limit for reinforced concrete slender columns in single and multi-story frames

Author(s):  
Mohamed Gamal Aboelhassan ◽  
Mohie Eldin Shoukry ◽  
Said Mohamed Allam

Abstract The main purpose of this paper is to study analytically the behavior of slender reinforced concrete columns existing in sway and non-sway structures. The studied variables were the stiffness of the beam connected to the slender columns, the stiffness of the bracing columns, and the number of bays and stories in the structure model. The stability of slender columns was studied and the required limits for the lateral bracing were determined using a finite element program to perform buckling analysis, linear analysis, and geometric nonlinear analysis for the different frame structural models. All the results obtained in this study were compared to the available methods included in the different building codes and the methods suggested by other researchers. The results indicated that the minimum value of the bracing limit, required to restrain the slender column against the side-sway, depends on the stiffness of the connecting beams, number of stories, and number of bays. The required bracing limit decreases with increasing the beam stiffness and with increasing the number of bays. However, the required bracing limit increases with the increase of the number of stories in the structure.

1991 ◽  
Vol 18 (5) ◽  
pp. 765-771 ◽  
Author(s):  
Antoine E. Lahoud

High-strength concretes are being increasingly used in the columns of high-rise buildings. Analytical studies of the slenderness effects in these columns have been very limited. The behavior of slender columns with normal- and high-strength concretes is studied using a finite element program. Differences and similarities in long-term and short-term behaviors between high-strength and normal-strength slender concrete columns are noted and discussed. Key words: columns, slenderness, high-strength concrete, creep, finite elements.


Author(s):  
Andrew H. C. Chan ◽  
Jian-Hua Ou

Wave-induced liquefaction is one of the main factors influence the stability of marine structures. However, the investigation on this phenomenon is complicated as the dynamic interaction between soil, pore fluid and the structure is closely coupled. In order to obtain a better understanding of the wave-induced response around the circular caisson founded in the seabed, three dimensional numerical analyses have been performed using the 3D finite element program DYNE3WAC in order to investigate the wave-induced response around the circular caisson.


2018 ◽  
Vol 149 ◽  
pp. 02016 ◽  
Author(s):  
Yehya Temsah ◽  
Ali Jahami ◽  
Jamal Khatib ◽  
M Sonebi

Many engineering facilities are severely damaged by blast loading. Therefore, many manufacturers of sensitive, breakable, and deformed structures (such as facades of glass buildings) carry out studies and set standards for these installations to withstand shock waves caused by explosions. Structural engineers also use these standards in their designs for various structural elements by following the ISO Damage Carve, which links pressure and Impulse. As all the points below this curve means that the structure is safe and will not exceed the degree of damage based on the various assumptions made. This research aims to derive the Iso-Damage curve of a reinforced concrete beam exposed to blast wave. An advanced volumetric finite element program (ABAQUS) will be used to perform the derivation.


2001 ◽  
Vol 7 (6) ◽  
pp. 419-424
Author(s):  
Arvydas Jurkša

The author has created a new technology for concrete beam, column, slab, wall and shell reinforcement computation according to the finite element program COSMOS/M analysis results and code of practice valid in Lithuania. A brief description of the technology is included in the article. Computer programmes COSARM and COSMAX were designed for slab, wall and shell reinforcement computation. Results can be visualized graphically. New computer programmes BEAM, COSBEAM, COLUMN, COSREC and COSCIR were created for beam and column reinforcement computation. The new technology extremely enlarged the possibilities of the powerful finite element program COSMOS/M and enabled to compute very complicated reinforced concrete structures.


Author(s):  
K. Ramesh ◽  
R. G. Kirk

Abstract A PC-based program has been developed which is capable of performing stability analysis and response calculations of rotor-bearing systems. The paper discusses the modeling of rotors supported on active magnetic bearings (AMB) and highlights the advantages in the modeling using the finite element method, over the transfer matrix method. An 8-stage centrifugal compressor supported on AMB was chosen for the case study. The results for the stability analysis, obtained using the finite element program was compared with those obtained by the well established transfer matrix codes. The results of unbalance response, including the effects of sensor non collocation are presented and this demonstrates how an AMB supported rotor can experience a synchronous instability for selected sensor locations and balance distributions.


Author(s):  
Pangil Choi ◽  
Lochana Poudyal ◽  
Fouzieh Rouzmehr ◽  
Moon Won

The performance of continuously reinforced concrete pavement (CRCP) in Texas has been quite satisfactory, primarily thanks to the continuous improvements in design and construction. However, severe spalling has been a major problem, and the Texas Department of Transportation (TxDOT) has sponsored several research projects since 1985 to identify solutions for this serious problem. Even though the research efforts were successful in identifying spalling mechanisms, developing a policy that TxDOT could easily implement has been a challenge. To develop a more practical solution to this problem, TxDOT initiated a research study, and the research efforts consisting of identifying CRCP projects with severe and no spalling, obtaining and conducting materials testing on concrete cores from those projects, analyzing the testing data, and performing theoretical analyses to validate the testing results. Among the material properties evaluated, the coefficient of thermal expansion (CTE) of concrete proved to have the best correlation with spalling. Detailed analyses of mechanistic behavior of concrete conducted with an object-oriented finite element program (OOF2) and commercial finite element program verified the reasonableness of the field-testing results. All concrete cores from CRCP with severe spalling had a CTE larger than 5.5 microstrains/°F, whereas no spalling was observed in concrete with a CTE less than that value. Based on this finding, TxDOT now requires the use of coarse aggregate that will produce concrete with a CTE of less than 5.5 microstrains/°F for CRCP construction. It is expected that this implementation will reduce the spalling in CRCP substantially.


2012 ◽  
Vol 594-597 ◽  
pp. 126-129 ◽  
Author(s):  
Rong Fang Zhou ◽  
Xue Wen Lei ◽  
Qing Shan Meng ◽  
Cong Lin

The principle of effective stress based on unsaturated soil material model and the boundary conditions of rainfall infiltration on the slope are introduced. The numerical model is built according to the example, and then the ABAQUS finite element program, which is combined with fluid-solid coupling, is used to simulate the problem of transient seepage field caused by rainfall infiltration. With the powerful post processing functions ability of ABAQUS program, we can observe the variation law with the time of pore-pressure distribution and displacement field and equivalent plastic strain. Moreover, the effect on the stability of slope under rainfall infiltration is analyzed.


2012 ◽  
Vol 4 (4) ◽  
pp. 320-325
Author(s):  
Aidas Jokūbaitis ◽  
Arnoldas Šneideris

The article discusses principles calculating resistance of a reinforced concrete column to fire. The paper provides column calculation models, the main characteristics of materials and characteristic stress set points applying finite element program SolidWorks. A comparative analysis of stresses in the cross-section of the reinforced concrete column and the reinforced concrete column strengthened with a metallic shell is made. Santrauka Analizuojami gelžbetoninės kolonos atsparumo ugniai skaičiavimo principai. Pateikiami baigtinių elementų programa SolidWorks sudaryti kolonų skaičiuojamieji modeliai, pagrindinės medžiagų charakteristikos ir būdingi įtempių nustatymo taškai. Atliekama gelžbetoninės ir sustiprintos metaliniu apvalkalu gelžbetoninės kolonos įtempių skerspjūvyje lyginamoji analizė.


2019 ◽  
Vol 54 (5) ◽  
Author(s):  
Haider K. Ammash ◽  
Safa S. Kadhim

In the present study, the effect of using reinforced concrete column capital on the punching shear strength of flat slab was investigated. The study was divided into two lines, the first line was the experimental study involves the molding four reinforced concrete flat slab models with dimensions (1600×1600×100 mm) with three different dimensions of column capital (400×400 mm, 600×600 mm, and 800×800 mm) in addition to reference model without columns capital (column dimension 200×200 mm). The second line that numerical modeling through the ABAQUS finite element program was introduced. Effect of column’s capital size and shape of column’s capital (rectangular and circular) were studied experimentally and numerically. A good agreement was obtained between the experimental and theoretical study. The main conclusion that the punching shear strength of reinforced concrete flat slab was affected on the size and shape of a column capital.


2019 ◽  
Vol 3 (1) ◽  
pp. 1-11
Author(s):  
Régis Marciano de Souza ◽  
Ricardo Rodrigues Magalhães ◽  
Ednilton Tavares de Andrade

This paper analyzes the non-linear geometric behavior of reinforced concrete slender columns. This approach is due to the fact that there is a tendency to reinforced concrete slender constructions, which may have significant second order effects. This research aimed at comparing different formulations for the analysis of non-linear behavior of reinforced concrete slender columns by comparing results from simulated problem (slender column with ten load scenarios) between the Finite Element Method (FEM) and the Iterative Process P-DELTA(P-Δ). Numeric results revealed that the Iterative Process P-Δ presented different results from FEM and that the second order effects are significant for reinforced concrete slender column problems.


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