- New York, New York, United States
- r. Ihssan Tarsha is a professor at the Department of Structural Engineering at Al-Baath University in Syria. He super... morer. Ihssan Tarsha is a professor at the Department of Structural Engineering at Al-Baath University in Syria. He supervised several master's and doctoral dissertations and graduation projects at the Faculty of Civil Engineering. His research interests include nonlinear structural analysis and testing of structural elements under different conditions of exposure to fire or torsion. and confined columns by FRP or steel jacketing and interest in a numerical study using the finite element method.edit
Improvements of reinforced concrete beams against the impact of torsional forces are among the most researched issues in construction studies. In this paper, repairing and strengthening reinforced concrete beams using ferrocement... more
Improvements of reinforced concrete beams against the impact of torsional forces are among the most researched issues in construction studies. In this paper, repairing and strengthening reinforced concrete beams using ferrocement laminates attached onto the surface of the beams and exposed to torsion were reviewed. This study aims to reveal the efficacy of the wrapping sides of ferrocement laminates. Previous experimental studies were conducted by using SBR as a slurry for strengthening beams by ferrocement from two-and three-side wrapping. Alternatively, the influence of using SBR as an ingredient of the mortar on the performance of the strengthened beams under torsion was discussed. The results showed that ferrocement is a practical alternative strengthening component for rehabilitating and repairing reinforced concrete beams. It was demonstrated that three-side wrapping improves the torsional behaviour in comparison with two-side wrapping. Also, the SBR preserved the required joining until failure for all the strengthened beams.
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This study investigates the performance of reinforced concrete (RC) columns following fire exposure. In the first phase of the study, we examined the effect of various high-temperature environments on the residual load-bearing capacity of... more
This study investigates the performance of reinforced concrete (RC) columns following fire exposure. In the first phase of the study, we examined the effect of various high-temperature environments on the residual load-bearing capacity of columns. In the second phase, the strengthening method is intended to increase the concrete strength through confinement to restore or improve the load capacity of fire-damaged columns. The RC columns were damaged after being exposed to fire for different periods of time to the medium and long fire (30 or 90 min) of the ASTM-E119 from the four-sided standard fire curve and then tested under axial loading up to failure. Concrete's compressive strengths are 25, 30, 35, and 40 MPa. The results indicated that the column's bearing capacity decreases proportionally with the length of time it is subjected to fire. In addition, it was discovered that the fortifying procedure employed herein restored up to 180 percent of the capacity of columns exposed to fire for an hour. In terms of strength, the technique involving composite confinement and steel slabs produced superior results.
Research Interests:
This research presents a numerical study of the behavior of reinforced columns with a square cross section subjected to eccentric stress under the influence of fire. As a first step, the study examined the effects of exposing columns to... more
This research presents a numerical study of the behavior of reinforced columns with a square cross section subjected to eccentric stress under the influence of fire. As a first step, the study examined the effects of exposing columns to fire with an increasing temperature up to 600°C for 60 minutes under eccentric loading conditions (e/b = 0, 0.1, 0.15, 0.20). As a second step, the columns were strengthened with a 100-mm concrete jacket and shirts supported by a steel structure consisting of vertical angles and horizontal spreaders to determine the effectiveness of the strengthening in increasing the resistance of these damaged columns. After the fire, this type of reinforcement is considered better than reinforcement with concrete shirts, reinforcement with carbon fiber-reinforced polymers, and others because of its advantages. There are many advantages to the ease and speed of implementation. The results showed that the columns that were repaired and strengthened after the fire with the steel structure casing led to a significant increase in resistance. It was found that the greater the thickness of the steel structure, the greater the resistance, and that the greater the eccentricity ratio, the lower the resistance as well as the collapse load.
Research Interests:
Concrete structures are among the most common types of structural in the World, so studying the behavior and collapse of these structures is one of the most important fields of study. Failures occur in concrete structures because of many... more
Concrete structures are among the most common types of structural in the World, so studying the behavior and collapse of these structures is one of the most important fields of study. Failures occur in concrete structures because of many factors such as earthquakes, explosions, landslides, fire, and other causes. Fires still represent a prime threat to the safety of
Research Interests:
ABSTRACT The effect of torsion moments on reinforced concrete beams have much attention and complicate ,that if these moments are combined with shear and bending moments or act alone (pure torsion). creating opening in these beams... more
ABSTRACT The effect of torsion moments on reinforced concrete beams have much attention and complicate ,that if these moments are combined with shear and bending moments or act alone (pure torsion). creating opening in these beams will reduce their strong a lot. This research study the effect of strengthening these beams , if we create opening in them , with CFRP to improve the ultimate torsion. The research conclude that creating an opening in the beams reduce the strength about 70% , while strengthen with CFRP increase the strength about three times compared with beams with opening.
Research Interests:
In this research, a strengthening method is suggest to confine reinforced concrete circular columns, exposed to axial force, by using a steel structure, which consists of vertical plates extending all over the height of the column and... more
In this research, a strengthening method is suggest to confine reinforced concrete circular columns, exposed to axial force, by using a steel structure, which consists of vertical plates extending all over the height of the column and transverse plates (ring plates). The research represents an experimental study to show the effect of this strengthening form on the behavior of reinforced concrete circular columns by using different compressive strengths of concrete, and its effect on reinforced concrete circular columns(ultimate load, ductility, and models of failure). The research makes it clear that confining of reinforced concrete circular columns by steel structure results in an increase in the ultimate axial load and ductility. Models of failure change with a strengthening form. The confinement has a clear effect on the low compressive strength of concrete.
Research Interests:
Compressive strength of concrete is the criterion that determines the validity of using concrete mix in engineering projects. Compressive strength of concrete depends on a lot of factors which don't have clear relationship , in... more
Compressive strength of concrete is the criterion that determines the validity of using concrete mix in engineering projects. Compressive strength of concrete depends on a lot of factors which don't have clear relationship , in addition that some of them are unclear and couldn't be measured. Therefore, finding method to estimate compressive strength of concrete specimen before the placement with acceptable accuracy is desirable, even if there is lack of some information like manner of placement or boundary conditions. This study presents first step to benefit of artificial neural network techniques which prove it's effective in a lot of applications in medical , engineering , financial. . .etc. We choose feed forward networks using back-propagation depending on weights and kinds of materials in the mix, and training the network with data of real experiments, and then test it. The results demonstrates that neural networks are effective in estimating the compressive strength of concrete based on the mix properties , and in learning even there is lack of some influenced factors.
Research Interests:
Research Interests:
This paper presents results from an experimental study including testing five reinforced concrete beams in order to investigate the efficiency of external strengthening of such beams when provided with large openings within their shear... more
This paper presents results from an experimental study including testing five reinforced concrete beams in order to investigate the efficiency of external strengthening of such beams when provided with large openings within their shear zones. Firstly tow beams were considered. One of these beams was solid without any openings and was considered as a control beam. The second beam was provided with one opening within the shear zone but without any strengthening and was also considered as a control beam. Secondly, three beams provided with openings at the same location and having the same dimensions like the second. Such three beams were externally strengthened with steel plates along the opening edges. It was found that the steel plates used for strengthening and its configuration scheme significantly affects the efficiency of strengthening in terms of beam deflection, steel strain, cracking, ultimate capacity and failure mode because using steel plates restored the beam shear strength .Finally, theoretical analysis was performed for all tested beams with openings in order to calculate the ultimate shear force carried by such beams. Equations presented by empirical formulas found in the literature were used to perform the theoretical analysis. Good agreement was observed between the theoretical results and the experimental ones.
Research Interests:
The purpose of this research is studying the effect of openings on the behavior of reinforced concrete beams under shear action using three dimensions nonlinear model by finite element method. The beams are simply supported with... more
The purpose of this research is studying the effect of openings on the behavior of reinforced concrete beams under shear action using three dimensions nonlinear model by finite element method. The beams are simply supported with rectangular section and without additional reinforcement in opening region. The opening is rectangular in shape with variable dimensions and constant position from the support. Studying the effect of changing depth and length of the opening on the behavior of the reinforced concrete beams was conducted. Modeling of the beams was made using Ansys package which uses finite element technique .The ultimate load , the modes of cracks , (load-deflection) relationship and the mode of failure for every beam were achieved. The study showed that introducing an opening in shear region reduces the strength and alter the mode of failure from flexural failure to shear failure , and any addition in the depth or length of the opening lead to early cracks , more deflections and less ultimate failure load. Also the study showed a large approximate between the analytical and experimental results for solid beam without opening
Research Interests:
The aim of this study is to numerically investigate the feasibility of confinement, the load carrying capacity and the temperature at which the confinement become obsolete for a RC column with dimensions of [200x200x 800 mm] subjected to... more
The aim of this study is to numerically investigate the feasibility of confinement, the load carrying capacity and the temperature at which the confinement become obsolete for a RC column with dimensions of [200x200x 800 mm] subjected to a standard fire loads (ISO834) from four sides. The study was carried out using the research-oriented FE code ANSYS APDL. ANSYS can integrate the nonlinear behavior of concrete by accounting for both crushing under compression stresses and cracking under tensile stresses, and well as the bilinear behavior of the reinforcing steel.The Numerical program was subcategorized into two major groups. The first one consisted of thirteen models. Those models were analyzed under static loading conditions. The second group consisted of 72 models. The models in this group where subjected to both structural and thermal loading conditions. The structural loading was in a form of static service loads, while the thermal loading was in a form of standard fire curve that has been applied to the four faces of the column.The numerical results were compared with experimental results as far as possible, in order to verify the accuracy of the numerical models used. The numerical analysis aimed to study of the effect of many variables, i.e., the diameter of the lateral reinforcement, the diameter of the longitudinal reinforcement.The results revealed the accuracy of the analytical models when compared to the experimental studies. A positive effect was captured in terms of the load carrying capacity and delaying the failure time, i.e., loss in confinement effect, when increasing 1) the diameter of the longitudinal, 2) the diameter of the transverse reinforcement and Additionally, the results indicated an increase in the column loading time under thermal loading conditions when static design loads are applied. And when the percentage of failure load increased, the time of carrying columns of fire decreased. Keywords : Finite Element Theory, Thermal Analysis, Reinforced Concrete Columns
Research Interests:
Solution of a problem of elasticity requires the solution of a system of 15 equations with 15 unknowns. A symmetric elimination of some the unknowns has allowed us to reduce the system of equations, either in terms of displacement or in... more
Solution of a problem of elasticity requires the solution of a system of 15 equations with 15 unknowns. A symmetric elimination of some the unknowns has allowed us to reduce the system of equations, either in terms of displacement or in terms of stresses. This suggests various methods that can be used in solving elasticity problems. Some of these methods depend primarily on intuition, while other are based on a systematic application of techniques of applied mathematics. This paper focuses on the numerical method for solution of two-dimensional elasticity problem.
Research Interests:
FRP reinforced polymers are widely accepted for use in civil engineering applications to strengthen constructions and application of confinement on the concrete columns, thereby increasing their ductility and increasing their carrying... more
FRP reinforced polymers are widely accepted for use in civil engineering applications to strengthen constructions and application of confinement on the concrete columns, thereby increasing their ductility and increasing their carrying capacity as these materials are characterized by high tensile strength. With the development of computer simulation theories to study the behavior of elements and structures under the influence of different loads (static, dynamic, thermal, etc.), it is possible to study the behavior of concrete columns under the influence of axial vertical and non-axial structural loads, and compare the results with previous research, thus saving time, effort and cost instead Of laboratory testing. In this paper, an analytical study was conducted using the ANSYS Workbench method, which follows the finite element method, to determine the effect of confinement using CFRP on carrying capacity of concrete columns and to compare analytical results with experimental results.
Research Interests:
Research Interests:
ABSTRACT The effect of torsion moments on reinforced concrete beams have much attention and complicate ,that if these moments are combined with shear and bending moments or act alone (pure torsion). creating opening in these beams... more
ABSTRACT The effect of torsion moments on reinforced concrete beams have much attention and complicate ,that if these moments are combined with shear and bending moments or act alone (pure torsion). creating opening in these beams will reduce their strong a lot. This research study the effect of strengthening these beams , if we create opening in them , with CFRP to improve the ultimate torsion. The research conclude that creating an opening in the beams reduce the strength about 70% , while strengthen with CFRP increase the strength about three times compared with beams with opening.
Research Interests:
FRP-reinforced polymers are widely accepted for use in civil engineering applications to strengthen constructions and apply confinement on concrete columns, thereby increasing their ductility and increasing their carrying capacity, as... more
FRP-reinforced polymers are widely accepted for use in civil engineering applications to strengthen constructions and apply confinement on concrete columns, thereby increasing their ductility and increasing their carrying capacity, as these materials are characterized by high tensile strength, high strength-to-weight ratio and high corrosion resistance,… etc. In addition, the exposure of reinforced concrete structures to fire is one of the most dangerous challenges that lead to great destruction and structural failure in addition to loss of life. With the development of computer simulation theories to study the behavior of elements and structures under the influence of different loads (static, dynamic, thermal,… etc.), it is possible to study the behavior of concrete columns under the influence of axial vertical and non-axial structural loads and compare the results with those of previous research, thus saving time, effort and cost instead of laboratory testing. Strengthening concrete columns with fiber-reinforced polymers (FRPs) has been studied extensively, but the majority of published studies have focused on circular columns. Most concrete columns in the field have square or rectangular cross-sections and resist eccentric loading as well. The objective of this study is to investigate the performance of square reinforced concrete (RC) columns, wrapped with carbon FRP subjected to elevated temperature; so, in this paper, an analytical study was conducted using the ANSYS Workbench program, which follows the finite element method, to determine the effect of layer number of CFRP on carrying capacity of concrete columns and to study the effect of external standard fire on concrete columns confined with CFRP. The numerical results were compared with experimental results as far as possible. The study revealed the accuracy of analytical models when compared to experimental studies. The results have shown that with increasing the layer number of CFRP, the carrying capacity of concrete columns will increase, with no benefit of increasing the number of CFRP layers to be more than 4, where polymer materials are sensitive to fire so that they need insulation.
Research Interests:
This research presents analytical study of a number of Reinforced Concrete Columns models which have square cross section and confined/unconfined by steel Structure of vertical angles and horizontal plates. Columns are subjected to... more
This research presents analytical study of a number of Reinforced Concrete Columns models which have square cross section and confined/unconfined by steel Structure of vertical angles and horizontal plates. Columns are subjected to centric and eccentric compression load. The objective is to know how far the bracing is effective in increasing the strength of these columns. This type of strengthening is considered better than the concrete Structure, Carbon Fiber Reinforced Polymer (CFRP) and other types because it has many features, easy and fast to be constructed. The study demonstrated that the bracing by steel Structure led to increase the strength in large ratios and had been clear that once the thickness of steel Structure is increased, the strength increases. And once the eccentricity is increased, the strength decreases and also the failure load.
Research Interests:
In this research, a strengthening method is suggest to confine reinforced concrete circular columns, exposed to axial force, by using a steel structure, which consists of vertical plates extending all over the height of the column and... more
In this research, a strengthening method is suggest to confine reinforced concrete circular columns, exposed to axial force, by using a steel structure, which consists of vertical plates extending all over the height of the column and transverse plates (ring plates). The research represents an experimental study to show the effect of this strengthening form on the behavior of reinforced concrete circular columns by using different compressive strengths of concrete, and its effect on reinforced concrete circular columns(ultimate load, ductility, and models of failure). The research makes it clear that confining of reinforced concrete circular columns by steel structure results in an increase in the ultimate axial load and ductility. Models of failure change with a strengthening form. The confinement has a clear effect on the low compressive strength of concrete.
Research Interests:
The purpose of this research is studying the effect of openings on the behavior of reinforced concrete beams under shear action using three dimensions nonlinear model by finite element method. The beams are simply supported with... more
The purpose of this research is studying the effect of openings on the behavior of reinforced concrete beams under shear action using three dimensions nonlinear model by finite element method. The beams are simply supported with rectangular section and without additional reinforcement in opening region. The opening is rectangular in shape with variable dimensions and constant position from the support. Studying the effect of changing depth and length of the opening on the behavior of the reinforced concrete beams was conducted. Modeling of the beams was made using Ansys package which uses finite element technique .The ultimate load , the modes of cracks , (load-deflection) relationship and the mode of failure for every beam were achieved. The study showed that introducing an opening in shear region reduces the strength and alter the mode of failure from flexural failure to shear failure , and any addition in the depth or length of the opening lead to early cracks , more deflections and less ultimate failure load. Also the study showed a large approximate between the analytical and experimental results for solid beam without opening
Research Interests:
Experimental studies have shown the importance of confinement in the granting of structural elements additional properties, especially the columns, where the confinement increases their ductility and carrying capacity. The previous... more
Experimental studies have shown the importance of confinement in the granting of structural elements additional properties, especially the columns, where the confinement increases their ductility and carrying capacity. The previous studies dealt with the subject of confinement in terms of addition of polymeric segments with certain timings or winding of columns entirely in carbon fiber. The study will examine the effect of changing the diameter of the longitudinal and lateral reinforcement on the carrying capacity of the concrete columns and compare the value of the compressive strength of concrete, which is associated with the theoretical relations provided by (Mander), (Park et all) by building an analytical model using finite element Program ANSYS.
Research Interests:
In this paper is presented the solution for an elastic problem for plane stress. The problem refers to a composite (built-up) plate from rectangular and centric circular ring, subjected to uniform external and internal pressure. The used... more
In this paper is presented the solution for an elastic problem for plane stress. The problem refers to a composite (built-up) plate from rectangular and centric circular ring, subjected to uniform external and internal pressure. The used method is the complex variable method and conformal mapping. The complex stress function can be found in the Laurenrt series and can be determined from the boundary conditions by solution a set of linear algebraic equations. The number of equations needed for sufficient accuracy depends upon the boundary shapes and loading conditions of the problem.
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This paper presents the results of analyzing 17 models with nonlinear static analysis. The models are 5, 10 and 15-story frame-wall structures with Re-entrant corners. The participations of frames to resist the shear force range between... more
This paper presents the results of analyzing 17 models with nonlinear static analysis. The models are 5, 10 and 15-story frame-wall structures with Re-entrant corners. The participations of frames to resist the shear force range between 25% and 60%. Moreover, There are 3 frame models used for comparing the performance of dual systems and frame systems. The lateral load pattern is first-mode pattern. The performance points are calculated by Equivalent Linearization and the target displacements are calculated by Displacement Modification. The results are compared with the roof displacements calculated by nonlinear dynamic analysis. The plastic hinges have been studied and numbers of plastic hinges have been compared with the change of frames participations.
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To evaluate the ultimate load of composite columns " steel-concrete " having square or circular steel tubes filled hollow section with concrete and Longitudinal reinforcing steel bars and subjected to centrically load and Exposed to the... more
To evaluate the ultimate load of composite columns " steel-concrete " having square or circular steel tubes filled hollow section with concrete and Longitudinal reinforcing steel bars and subjected to centrically load and Exposed to the standard fire in accordance with ISO 834 curve along and from all sides, The fire duration , the buckling length of the column , geometrical and mechanical properties of each material for structural and reinforcing steels and concrete are in the base of the method given in the French National Annex of EN 1994-1-2. The thermal and mathematical analyses to evaluate the ultimate centrically load according to French National Annex of EN 1994-1-2 and comparing it with Euro code 4 Part 1.2 is the purpose of this research .
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Complex potential method which used in plane elasticity theory problems is considered one of the most important wide used methods after development of electronic computers. This research can be considered a practical application to... more
Complex potential method which used in plane elasticity theory problems is considered one of the most important wide used methods after development of electronic computers. This research can be considered a practical application to complex function approach in order to find tangential stresses of cylindrical bar under torsional moment. The two hall along its length are located on the same diameter and on two different faces. Q.Basic computer program has been used to obtain on the values of the tangential stresses at number of points on the same axis. This program will solved group of algebraic linear equations required. It should be noted that the number of equations depend on the solution accuracy required .
Research Interests:
complex potential method which used in plane elasticity theory problems is considered one of the most important wide used methods after development of electronic computers. this research is a practical application of complex function... more
complex potential method which used in plane elasticity theory problems is considered one of the most important wide used methods after development of electronic computers. this research is a practical application of complex function approach in order to find tangential stresses of cylindrical bar consisting of three different material pipes under torsional moment. Q. Basic computer program has been used to obtain on the values of the tangential stresses at number of points on the same axis. this program will solve a group of algebraic linear equations required. it should be noted that the number of equation depend on the solution accuracy required .
Research Interests:
Calculation of fire resistance for any structural member divided in two independent steps. The first step involves predicting the temperature distribution inside the structural members, referred to as 'thermal analysis'. The second step... more
Calculation of fire resistance for any structural member divided in two independent steps. The first step involves predicting the temperature distribution inside the structural members, referred to as 'thermal analysis'. The second step of the analysis, termed the 'structural analysis', is carried out for the main purpose of determining the response of the structure due to static and thermal loading. The first stages of analysis are discussed in this paper. using finite element method by a structural analysis program " ANSYS "
Research Interests:
The Using of composite columns " steel-concrete " in structural civil engineering constructions has been increased, because its good capacity to bearing loads and on the other hand his advantage to fire resistance when the concrete cased... more
The Using of composite columns " steel-concrete " in structural civil engineering constructions has been increased, because its good capacity to bearing loads and on the other hand his advantage to fire resistance when the concrete cased the steel section which called Concrete Cased Columns. The safely and economically design of these columns under fire is relating to determine fire modeling which produce sever heat at composite column, and so to calculate temperature in composite steel-concrete columns to employ fire modeling for the safely and economically design. temperature distribution in a composite steel-concrete column is studied using ANSYS program which finite element employed.
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This paper aims to Studying the behavior of Wall-Frame Structures with Curtailed Shear Walls using Non-linear Static Analysis. Comparison with the behavior of Wall-Frame Structures with Shear walls at full height, and determine the... more
This paper aims to Studying the behavior of Wall-Frame Structures with Curtailed Shear Walls using Non-linear Static Analysis. Comparison with the behavior of Wall-Frame Structures with Shear walls at full height, and determine the optimum level of curtailment according to the evaluation of the performance of the building when exposed to earthquakes, Several models of buildings of different heights have been studied, The result was that: It is useful to stop the shear walls up to 70% of the entire height, which is reflected positively in reducing the construction cost and developing its seismic performance.
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This paper presents results from an experimental study including testing five reinforced concrete beams in order to investigate the efficiency of external strengthening of such beams when provided with large openings within their shear... more
This paper presents results from an experimental study including testing five reinforced concrete beams in order to investigate the efficiency of external strengthening of such beams when provided with large openings within their shear zones. Firstly tow beams were considered. One of these beams was solid without any openings and was considered as a control beam. The second beam was provided with one opening within the shear zone but without any strengthening and was also considered as a control beam. Secondly, three beams provided with openings at the same location and having the same dimensions like the second. Such three beams were externally strengthened with steel plates along the opening edges. It was found that the steel plates used for strengthening and its configuration scheme significantly affects the efficiency of strengthening in terms of beam deflection, steel strain, cracking, ultimate capacity and failure mode because using steel plates restored the beam shear strength .Finally, theoretical analysis was performed for all tested beams with openings in order to calculate the ultimate shear force carried by such beams. Equations presented by empirical formulas found in the literature were used to perform the theoretical analysis. Good agreement was observed between the theoretical results and the experimental ones.
Research Interests:
This study contains two parts. The first one is a theoretical study to find mathematical model and for determination shear stresses in a thick walled cylinder with two circular holes under torsion moments using plane theory of elasticity... more
This study contains two parts. The first one is a theoretical study to find mathematical model and for determination shear stresses in a thick walled cylinder with two circular holes under torsion moments using plane theory of elasticity and complex potential method which are defined its constant coefficients by jointly solution of three groups of Algebria linearly infinitely equations. The second parts contains general program written by (Q.Basic) language which can be used for the solution of Algebra equations with any limit number of equations taken form each group. And determination shear stresses for number of points located on the same axis .
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This paper presents the using of conformal transformation or mapping to solve some of the third fundamental boundary problems form two-dimensional elasticity for plane stress. The problem consists of composite (built-up) plate bounded by... more
This paper presents the using of conformal transformation or mapping to solve some of the third fundamental boundary problems form two-dimensional elasticity for plane stress. The problem consists of composite (built-up) plate bounded by the simple closed curve that is known as Jordan's curve such as "square, hexagon, octagon, equilateral triangle, and elliptical cross-section ". The plate was interconnected by force a circular ring subjected to uniform internal pressure 3 P at contour 3 L. To determine the stresses) ; (y x in the presented problem we will look for the stress function in each domain or region 1,2 = j j S at complex form using complex variables method and conformal mapping. The complex stress functions can be found in the Laurent series expansions. from the boundary conditions the values of the constant " coefficients of Laurent's series " Can be determined by solution a set of linear algebraic equations.
Research Interests:
Solution of a problem of elasticity requires the solution of a system of 15 equations with 15 unknowns. A symmetric elimination of some the unknowns has allowed us to reduce the system of equations, either in terms of displacement or in... more
Solution of a problem of elasticity requires the solution of a system of 15 equations with 15 unknowns. A symmetric elimination of some the unknowns has allowed us to reduce the system of equations, either in terms of displacement or in terms of stresses. This suggests various methods that can be used in solving elasticity problems. Some of these methods depend primarily on intuition, while other are based on a systematic application of techniques of applied mathematics. This paper focuses on the numerical method for solution of two-dimensional elasticity problem.
Research Interests:
Concrete installations can be strengthened, repaired, restored and developed through the use of fiber-reinforced polymers. The use of these materials has increased in recent years due to the many advantages of these compounds compared to... more
Concrete installations can be strengthened, repaired, restored and developed through the use of fiber-reinforced polymers. The use of these materials has increased in recent years due to the many advantages of these compounds compared to traditional materials such as steel, high strength to weight, high energy absorption Excellent resistance to corrosion, and high tensile strength. In this paper, an analytical study was carried out on a square-shaped and axial-axis model using the ANSYS Workbench method, which uses the finite element method, to determine the impact of confinement using CFRP on the carrying capacity of concrete columns by taking the following variables: 1-Number of carbon fiber layers. 2-Rotating the edges of samples. The analytical results showed a good correlation with the experimental results. The analytical model showed the importance of rotating the edges of the cross section and the number of carbon fiber layers in increasing the carrying capacity of the concrete columns.
Research Interests:
This research presents an analytical study of many reinforced concrete buildings, with ribbed slabs, without openings and with openings in the middle or in the edges, in order to detect the effect of differences resulting from assuming... more
This research presents an analytical study of many reinforced concrete buildings, with ribbed slabs, without openings and with openings in the middle or in the edges, in order to detect the effect of differences resulting from assuming slabs as rigid or semi-rigid diaphragm on seismic performance of building. The study shows that the rigid diaphragm assumption results in large differences in shear forces, maximum story drifts and period. But, the semi-rigid diaphragm assumption results in noticeable difference in shear forces only. These differences are larger with edge openings, and get reduced by increasing number of stories.
Research Interests:
ABSTRUCT The aim of this study is to numerically investigate the feasibility of confinement, the load carrying capacity and the temperature at which the confinement become obsolete for a RC column with dimensions of [200x200x800 mm]... more
ABSTRUCT The aim of this study is to numerically investigate the feasibility of confinement, the load carrying capacity and the temperature at which the confinement become obsolete for a RC column with dimensions of [200x200x800 mm] subjected to a standard fire loads (ISO834) from four sides. The study was carried out using the research-oriented FE code ANSYS APDL. ANSYS can integrate the nonlinear behavior of concrete by accounting for both crushing under compression stresses and cracking under tensile stresses, and well as the bilinear behavior of the reinforcing steel. The Numerical program was subcategorized into two major groups. The first one consisted of thirteen models. Those models were analyzed under static loading conditions. The second group consisted of 72 models. The models in this group where subjected to both structural and thermal loading conditions. The structural loading was in a form of static service loads, while the thermal loading was in a form of standard fire curve that has been applied to the four faces of the column. The numerical results were compared with experimental results as far as possible, in order to verify the accuracy of the numerical models used. The numerical analysis aimed to study of the effect of many variables, i.e., the diameter of the lateral reinforcement, the diameter of the longitudinal reinforcement. The results revealed the accuracy of the analytical models when compared to the experimental studies. A positive effect was captured in terms of the load carrying capacity and delaying the failure time, i.e., loss in confinement effect, when increasing 1) the diameter of the longitudinal, 2) the diameter of the transverse reinforcement and Additionally, the results indicated an increase in the column loading time under thermal loading conditions when static design loads are applied. And when the percentage of failure load increased, the time of carrying columns of fire decreased. 2
Research Interests:
FRP reinforced polymers are widely accepted for use in civil engineering applications to strengthen constructions and application of confinement on the concrete columns, thereby increasing their ductility and increasing their carrying... more
FRP reinforced polymers are widely accepted for use in civil engineering applications to strengthen constructions and application of confinement on the concrete columns, thereby increasing their ductility and increasing their carrying capacity as these materials are characterized by high tensile strength. With the development of computer simulation theories to study the behavior of elements and structures under the influence of different loads (static, dynamic, thermal, etc.), it is possible to study the behavior of concrete columns under the influence of axial vertical and non-axial structural loads, and compare the results with previous research, thus saving time, effort and cost instead Of laboratory testing. In this paper, an analytical study was conducted using the ANSYS Workbench method, which follows the finite element method, to determine the effect of confinement using CFRP on carrying capacity of concrete columns and to compare analytical results with experimental results.
Research Interests:
Compressive strength of concrete is the criterion that determines the validity of using concrete mix in engineering projects. Compressive strength of concrete depends on a lot of factors which don't have clear relationship , in addition... more
Compressive strength of concrete is the criterion that determines the validity of using concrete mix in engineering projects. Compressive strength of concrete depends on a lot of factors which don't have clear relationship , in addition that some of them are unclear and couldn't be measured. Therefore, finding method to estimate compressive strength of concrete specimen before the placement with acceptable accuracy is desirable, even if there is lack of some information like manner of placement or boundary conditions. This study presents first step to benefit of artificial neural network techniques which prove it's effective in a lot of applications in medical , engineering , financial. . .etc. We choose feed forward networks using back-propagation depending on weights and kinds of materials in the mix, and training the network with data of real experiments, and then test it. The results demonstrates that neural networks are effective in estimating the compressive strength of concrete based on the mix properties , and in learning even there is lack of some influenced factors.
Research Interests:
The exposure of concrete structures to fire is one of the most dangers challenges that lead to great destruction and failure the structural in addition to loss of life. Great efforts have been made in many previous studies to study the... more
The exposure of concrete structures to fire is one of the most dangers challenges that lead to great destruction and failure the structural in addition to loss of life. Great efforts have been made in many previous studies to study the behavior of elements exposure to fire. Since columns are an important structural component, studying the impact of fire on them is an important subject. The study is performed on columns, under axial loading with cross-section (200 × 200 × 800) mm, and exposed to a standard fire (External Fire) from the four sides, at different time using the Finite Element program ANSYS Workbench, to determine the carrying capacity of columns when exposed to standard fire, and to determine the thermal distribution, in the cross section for the model. In addition, determination of the design load according to the isotherm500 method by taking advantage of the thermal analysis of the analytical model and the conclusion of a safety factor for the collapse load of the model studied.The results showed the effectiveness of the analytical model when compared with the experimental results, where the difference between the value of the analytical and experimental failure load (0.68%), ie, The analytical model is capable of characterizing any experimental model and this saves time, effort and cost. After the
Research Interests:
This paper is presented the solution for concentration and distribution stress in an web beam section opening with hexagonal shape, the top flange beam is subjected to external uniform load. And knowing the size effect circular conflation... more
This paper is presented the solution for concentration and distribution stress in an web beam section opening with hexagonal shape, the top flange beam is subjected to external uniform load. And knowing the size effect circular conflation edge of the hexagonal shape on the concentration stresses. Solution of this elasticity stress problem can be obtained by numerical model by finite elements method by a structural analysis program " ANSYS ". Then comparing the resultant and finding the right finite element for researched problem .
Research Interests:
Over the centuries, the world has witnessed many disasters that humans have not been able to control. Fire is one of the most devastating disasters that have caused human damage, prompting researchers to conduct numerous studies on the... more
Over the centuries, the world has witnessed many disasters that humans have not been able to control. Fire is one of the most devastating disasters that have caused human damage, prompting researchers to conduct numerous studies on the behavior of fire-prone elements and take action to minimize damage. With the development of computer simulation theories, it is possible to study the behavior of structures under the influence of different loads. Using the theory of finite elements, we can model the behavior of concrete in a nonlinear manner, taking into account the causes of the various failures. The study was carried out using the research-oriented FE code ANSYS APDL for concrete column under axial loading dimensions and subject to ASTM-E119 standard fire from the four sides to determine its capacity load when exposed to fire.
This paper is presented three methods for calculation of deflection in the simple beam with web Cellular or hexagonal opening web section , using finite element method by a structural analysis program " ANSYS " and complementary method... more
This paper is presented three methods for calculation of deflection
in the simple beam with web Cellular or hexagonal opening web section ,
using finite element method by a structural analysis program " ANSYS "
and complementary method and by elementary bending theory we have
differential equation of curvature axis and solving it with program
MATHLAB. And comparing between them.
in the simple beam with web Cellular or hexagonal opening web section ,
using finite element method by a structural analysis program " ANSYS "
and complementary method and by elementary bending theory we have
differential equation of curvature axis and solving it with program
MATHLAB. And comparing between them.
Research Interests:
This paper is presented the solution for concentration and distribution stress in an square plate containing a concentric circular hole, the plate is subjected to external uniform tensile stress of intensity P in the x and y directions.... more
This paper is presented the solution for concentration and distribution stress in an square plate containing a concentric circular hole, the plate is subjected to external uniform tensile stress of intensity P in the x and y directions. Solution of this elasticity stress problem can be obtained by three different methods : 1-Complex variable method and conformal mapping. 2-Airy's stress function assumed as polynomials in polar coordinates method. 3-Numerical methods by finite elements method by a structural analysis program " ANSYS ". Then comparing the resultant and finding suitable finite element for researched problem .