Wahba El-Tahan | Cairo University (original) (raw)

Papers by Wahba El-Tahan

Research paper thumbnail of Behavior of Bi-axially loaded short composite and internally RC columns

The aim of this research is to study the theoretical and experimental behavior of the short compo... more The aim of this research is to study the theoretical and experimental behavior of the short composite and that internally reinforced concrete columns subjected to eccentric compression force and biaxial bending. The parameters involved in this research are the eccentricity of the applied force and the ratio between (Mx and My) . Computer model is achieved using Microsoft - Excel spreadsheet based on the ultimate limit state method and strain compatibility according to the Egyptian Code (ECCS 203-2001) to develop interaction diagrams for two types of columns namely, composite columns named (C)-type and internally reinforced concrete columns named (R)-type. The developed interaction diagrams using the Excel spreadsheet were verified by comparison with the (PCA-Column program) results based on American code (ACI 318-99). The experimental program was set to test 8 specimens; 4 columns for each type, to compare the behavior of two previously mentioned types for the same external concrete dimensions and almost same area of steel inside section with nearly similar moments of inertia. Concrete and steel strains were recorded in addition to the lateral displacement and the section capacity for each column at each load increment. Relationships between load and both the compression and tension strains are also presented. The crack patterns, the mode of failure and the mechanical behavior are also illustrated for each column. Finally, the average ratio of the ultimate load level (R) and experimental failure load of internally reinforced columns (R-type) and composite (C-type) is about (85%), in addition to the similarity of the concrete compression strain, lateral deflection and pattern of failure of two column types, which is a good correlation between (R-type) and (C-type) columns.

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Research paper thumbnail of Fracture mechanics investigations of isotropic, jointed and bimodulus continua /

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Research paper thumbnail of A proposed technique of SFEM on solving ordinary random differential equation

Applied Mathematics and Computation, 2005

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Research paper thumbnail of Experimental Details of composite and Internally reinforcement columns

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Research paper thumbnail of Using FEM-RVT technique for solving a randomly excited ordinary differential equation with a random operator

Appl. Math. Comput., 2007

The technique of stochastic finite element (SFEM) which is the finite element technique FEM adapt... more The technique of stochastic finite element (SFEM) which is the finite element technique FEM adapted to stochastic problems can be re-described to use random variable transformation technique RVT. A new FEM-RVT technique was successfully used in solving stochastic problems with random excitation [M. El-Tawil, W. El-Tahhan, A. Hussein, A proposed technique of SFEM on solving ordinary random differential equation, J. Appl. Math. Comput. 161 (2005) 35-47]. In this paper, the technique is adapted to solve a randomly excited differential equation with a random operator. The technique shows high accuracy when solving a case study compared with the exact solution. Finally a problem with unknown exact solution is solved using this technique.

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Research paper thumbnail of A proposed technique of SFEM on solving ordinary random differential equation

Applied Mathematics and Computation, 2005

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Research paper thumbnail of Experimental tests on short composite and internally reinforced concrete columns

International Journal of …, 2011

Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eigh... more Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eight rectangular reinforced concrete columns with different parameters were tested under axial loads and biaxial bending. Four columns were internally reinforced with ...

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Research paper thumbnail of Experimental tests on short composite and internally reinforced concrete columns

International Journal of …, 2011

Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eigh... more Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eight rectangular reinforced concrete columns with different parameters were tested under axial loads and biaxial bending. Four columns were internally reinforced with ...

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Research paper thumbnail of Structural Analysis of Bimodular Materials

Journal of Engineering Mechanics, 1989

ABSTRACT

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Research paper thumbnail of BEHAVIOUR OF BIAXIALLY LOADED SHORT COMPOSITE AND INTERNALLY REINFORCED CONCRETE COLUMNS

The aim of this research is to study the theoretical and experimental behavior of the short compo... more The aim of this research is to study the theoretical and experimental behavior of the short composite and that internally reinforced concrete columns subjected to eccentric compression force and biaxial bending. The parameters involved in this research are the eccentricity of the applied force and the ratio between (Mx and My) .

Computer model is achieved using Microsoft - Excel spreadsheet based on the ultimate limit state method and strain compatibility according to the Egyptian Code (ECCS 203-2001) to develop interaction diagrams for two types of columns namely, composite columns named (C)-type and internally reinforced concrete columns named (R)-type. The developed interaction diagrams using the Excel spreadsheet were verified by comparison with the (PCA-Column program) results based on American code (ACI 318-99).
The experimental program was set to test 8 specimens; 4 columns for each type, to compare the behavior of two previously mentioned types for the same external concrete dimensions and almost same area of steel inside section with nearly similar moments of inertia.

Concrete and steel strains were recorded in addition to the lateral displacement and the section capacity for each column at each load increment.
Relationships between load and both the compression and tension strains are also presented. The crack patterns, the mode of failure and the mechanical behavior are also illustrated for each column.

Finally, the average ratio of the ultimate load level (R) and experimental failure load of internally reinforced columns (R-type) and composite (C-type) is about (85%), in addition to the similarity of the concrete compression strain, lateral deflection and pattern of failure of two column types, which is a good correlation between (R-type) and (C-type) columns.

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Research paper thumbnail of Behavior of Bi-axially loaded short composite and internally RC columns

The aim of this research is to study the theoretical and experimental behavior of the short compo... more The aim of this research is to study the theoretical and experimental behavior of the short composite and that internally reinforced concrete columns subjected to eccentric compression force and biaxial bending. The parameters involved in this research are the eccentricity of the applied force and the ratio between (Mx and My) . Computer model is achieved using Microsoft - Excel spreadsheet based on the ultimate limit state method and strain compatibility according to the Egyptian Code (ECCS 203-2001) to develop interaction diagrams for two types of columns namely, composite columns named (C)-type and internally reinforced concrete columns named (R)-type. The developed interaction diagrams using the Excel spreadsheet were verified by comparison with the (PCA-Column program) results based on American code (ACI 318-99). The experimental program was set to test 8 specimens; 4 columns for each type, to compare the behavior of two previously mentioned types for the same external concrete dimensions and almost same area of steel inside section with nearly similar moments of inertia. Concrete and steel strains were recorded in addition to the lateral displacement and the section capacity for each column at each load increment. Relationships between load and both the compression and tension strains are also presented. The crack patterns, the mode of failure and the mechanical behavior are also illustrated for each column. Finally, the average ratio of the ultimate load level (R) and experimental failure load of internally reinforced columns (R-type) and composite (C-type) is about (85%), in addition to the similarity of the concrete compression strain, lateral deflection and pattern of failure of two column types, which is a good correlation between (R-type) and (C-type) columns.

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Research paper thumbnail of Fracture mechanics investigations of isotropic, jointed and bimodulus continua /

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A proposed technique of SFEM on solving ordinary random differential equation

Applied Mathematics and Computation, 2005

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Experimental Details of composite and Internally reinforcement columns

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Using FEM-RVT technique for solving a randomly excited ordinary differential equation with a random operator

Appl. Math. Comput., 2007

The technique of stochastic finite element (SFEM) which is the finite element technique FEM adapt... more The technique of stochastic finite element (SFEM) which is the finite element technique FEM adapted to stochastic problems can be re-described to use random variable transformation technique RVT. A new FEM-RVT technique was successfully used in solving stochastic problems with random excitation [M. El-Tawil, W. El-Tahhan, A. Hussein, A proposed technique of SFEM on solving ordinary random differential equation, J. Appl. Math. Comput. 161 (2005) 35-47]. In this paper, the technique is adapted to solve a randomly excited differential equation with a random operator. The technique shows high accuracy when solving a case study compared with the exact solution. Finally a problem with unknown exact solution is solved using this technique.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A proposed technique of SFEM on solving ordinary random differential equation

Applied Mathematics and Computation, 2005

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Experimental tests on short composite and internally reinforced concrete columns

International Journal of …, 2011

Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eigh... more Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eight rectangular reinforced concrete columns with different parameters were tested under axial loads and biaxial bending. Four columns were internally reinforced with ...

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Research paper thumbnail of Experimental tests on short composite and internally reinforced concrete columns

International Journal of …, 2011

Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eigh... more Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eight rectangular reinforced concrete columns with different parameters were tested under axial loads and biaxial bending. Four columns were internally reinforced with ...

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Research paper thumbnail of Structural Analysis of Bimodular Materials

Journal of Engineering Mechanics, 1989

ABSTRACT

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Research paper thumbnail of BEHAVIOUR OF BIAXIALLY LOADED SHORT COMPOSITE AND INTERNALLY REINFORCED CONCRETE COLUMNS

The aim of this research is to study the theoretical and experimental behavior of the short compo... more The aim of this research is to study the theoretical and experimental behavior of the short composite and that internally reinforced concrete columns subjected to eccentric compression force and biaxial bending. The parameters involved in this research are the eccentricity of the applied force and the ratio between (Mx and My) .

Computer model is achieved using Microsoft - Excel spreadsheet based on the ultimate limit state method and strain compatibility according to the Egyptian Code (ECCS 203-2001) to develop interaction diagrams for two types of columns namely, composite columns named (C)-type and internally reinforced concrete columns named (R)-type. The developed interaction diagrams using the Excel spreadsheet were verified by comparison with the (PCA-Column program) results based on American code (ACI 318-99).
The experimental program was set to test 8 specimens; 4 columns for each type, to compare the behavior of two previously mentioned types for the same external concrete dimensions and almost same area of steel inside section with nearly similar moments of inertia.

Concrete and steel strains were recorded in addition to the lateral displacement and the section capacity for each column at each load increment.
Relationships between load and both the compression and tension strains are also presented. The crack patterns, the mode of failure and the mechanical behavior are also illustrated for each column.

Finally, the average ratio of the ultimate load level (R) and experimental failure load of internally reinforced columns (R-type) and composite (C-type) is about (85%), in addition to the similarity of the concrete compression strain, lateral deflection and pattern of failure of two column types, which is a good correlation between (R-type) and (C-type) columns.

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