Sherif Safar | Cairo University (original) (raw)
Papers by Sherif Safar
Design Engineering, Jul 16, 2021
Scientific Reports
The process of optimizing building designs requires developing several architectural and structur... more The process of optimizing building designs requires developing several architectural and structural layout alternatives. Traditionally, limited number of design iterations can be conducted manually, which is time consuming and results in non-optimum designs in terms of limited functionality or high costs. The goal of this research is to develop an advanced Building Information Modeling (BIM) model for automating and optimizing design of building layouts and structural elements to reach minimum construction cost while abiding by the functionality constraints of the architectural design. The developed model integrates concepts from structural design, BIM modeling, and computer programming into one advanced optimization framework. The model was tested and validated in 11 case studies and is found to reduce the structural materials cost by up to 15% per floor without compromising the defined space requirements.
Lecture notes in civil engineering, Jun 17, 2022
Steel and Composite Structures, 2019
World Academy of Science, Engineering and Technology, International Journal of Civil, Environmental, Structural, Construction and Architectural Engineering, 2017
Plate girders are used as an alternative in construction when hot rolled I-shaped beams show poor... more Plate girders are used as an alternative in construction when hot rolled I-shaped beams show poor strength or do not meet design requirements. Under high bending moments and shear forces, it is more efficient to use tapered plate girders. Current design codes lack specific design rules to estimate shear strength of plate girders with tapered web. The aim of this research is to investigate the elastic buckling and ultimate shear strengths of tapered end web panels in plate girders. More than two hundred detailed finite element models of plate girders with tapered end web panels are constructed and analyzed to cover a wide range of geometric parameters including: aspect ratio of end web panel, depth–to-thickness ratio of end web plate, inertia of intermediate stiffeners, and angle of tapering. Upon validation of the numerical solution, numerical results are used to establish a mathematical expression for the ultimate shear strength of prismatic and tapered end web panels. Design requi...
Cleaner Engineering and Technology
Experimental and analytical research work that was conducted on unstiffened triangular bracket pl... more Experimental and analytical research work that was conducted on unstiffened triangular bracket plates showed that there are many sources of complexities in this type of connections. Unlike analytical analysis that was concerned with elastic buckling, experimental research indicated that yielding along the free edge usually takes place prior to buckling and that the connection possesses a significant amount of post buckling strength. An expression relating the average stress on the loaded edge to the maximum stress along the free edge was based on analytical work and revised by test results to establish the connection carrying load capacity. A limiting value for the bracket plate width-to-thickness ratio was established to prevent plate buckling. In this paper, a finite element model was established for the connection incorporating geometric and material imperfections. Critical and limit load obtained was compared to conventional design method. Stress distribution in welds and contact stresses between bracket and beam were evaluated and compared to theoretical assumptions. Effect of triangular plate thickness and aspect ratio on connection behavior was investigated. It was shown that the design method based on previous analytical research work is conservative. The connection possesses a significant amount of post-buckling strength such that the limit load is almost twice the critical load.
Journal of Constructional Steel Research
Journal of Al-Azhar University Engineering Sector
There is a lack of study concerning the torsional loading effect on the flexural response of colu... more There is a lack of study concerning the torsional loading effect on the flexural response of column base especially cyclic behavior under combined torsional-flexural loading; many unknowns exist on this topic. A study for the flexural performance of the base connection for C-bent column subjected to seismic in the traffic direction is necessary to address the effect of the complex combination of cyclic flexural-torsional action on such a type of connection; for this purpose an extensive numerical parametric study was conducted to evaluate the flexural performance of the fixed base connection of C-bent bridge pier against combined cyclic bending and torsional loading following SAC phase II protocol. After verifying results with previous experimental works a Finite Element Analysis (FEA) using Strand7 is performed for Finite Element Models (FEM) which simulates force transfer at major contact interfaces in the connection, and a total of six base plate connection sub-assemblages with variable base plate thicknesses (three for stiffened connection and three for un-stiffened connection) anchored by 10 bolts, were configured and analyzed to support double cantilever pier subjected to eleven loading schemes that reflect different pairs of gravity moment and axial loads along with cyclic loading in the traffic direction eccentric from pier center of rigidity to guarantee the application of combined flexural-torsional action on the base connection. The study provided a curves for the following performance terms; strength (yield moment), deformation (yield curvature), curvature ductility, and stiffness (rotational flexural stiffness); the seismic flexural performance of the base connection under the previously mentioned loading package was evaluated by plotting the variation of the mentioned terms against the parametric values of the base plate thickness for different loading condition considered in the analysis. The study revealed that the state of gravity load weather it is concentric or eccentric has a great impact on the connection yield strength and deformation, further the level of eccentricity of the applied gravity loads has a significant impact on the connection stiffness, FLEXURAL BEHAVIOR OF BASE CONNECTION OF C-BENT COLUMN UNDER COMBINED CYCLIC BENDING-TORSIONAL LOADING more over increasing base plate thickness affect deformation capacity, and strength however with less impact on the strength and remarkable impact on the deformation, study also provided the effect of adding stiffeners to the connection, which enhanced the base fixation rigidity, however in turn of that curvature ductility has suffered noticeable reduction, in the same context curvature ductility is strongly deteriorated when the torsional stresses are dominant.
Journal of Al-Azhar University Engineering Sector
There is a lack of study concerning the torsional effect on the torsional response of column base... more There is a lack of study concerning the torsional effect on the torsional response of column base especially cyclic behavior under combined torsional-flexural loading; many unknowns exist on this topic. A study for the torsional performance of the base connection for C-bent column subjected to seismic in the traffic direction is necessary to address the effect of the complex combination of cyclic flexural-torsional action on such a type of connection; for this purpose an extensive numerical parametric study was conducted to evaluate the torsional performance of the fixed base connection of C-bent bridge pier against combined cyclic bending and torsional loading following SAC phase II protocol. After verifying results with previous experimental works a Finite Element Analysis (FEA) using Strand7 is performed for Finite Element Models (FEM) which simulates force transfer at major contact interfaces in the connection, and a total of six base plate connection sub-assemblages with variable base plate thicknesses (three for stiffened connection and three for un-stiffened connection) anchored by 10 bolts, were configured and analyzed to support double cantilever pier subjected to eleven loading schemes that reflect different pairs of gravity moment and axial loads along with cyclic loading in the traffic direction eccentric from pier center of rigidity to guarantee the application of combined flexural-torsional action on the base connection. The study provided a curves for the following performance terms; strength (ultimate torsion), deformation (ultimate twisting angle), and stiffness (torsional stiffness); the seismic torsional performance of the base connection under the previously mentioned loading package was evaluated by plotting the variation of the mentioned terms against the parametric values of the base plate thickness for different loading condition considered in the analysis.
Proceedings of the New Developments in Structural Engineering and Construction, 2013
ABSTRACT In this paper, the behavior of reinforced concrete beam-column connections strengthened ... more ABSTRACT In this paper, the behavior of reinforced concrete beam-column connections strengthened with Carbon Fiber Reinforced Plastic, CFRP, laminates was investigated by the finite element method. Numerical model of strengthened connections was verified by comparison to test results published in literature. A numerical investigation was conducted to assess the effect of CFRP strengthening configuration on the behavior of exterior beam-column connections belonging to a five-storey moment resisting frame. The load-deflection behavior, ultimate load, and ductility ratio of strengthened connections were compared to those of un-strengthened connections. It was shown that using full CFRP wraps on beams increased the ultimate load and stiffness of connections after first yielding of steel re-bars. Although strengthening connections with CFRP laminates altered their ductile failure mode to brittle failure by crushing of concrete, it was noticed that the application of CFRP wraps on beams extended to at least one-fifth of the beam span restored a significant portion of the connection ductility.
Journal of Engineering and Applied Science
Corner connections are crucial parts for the safety and adequate performance of steel frames. Ext... more Corner connections are crucial parts for the safety and adequate performance of steel frames. Extensive studies were made on the performance of square connections (without haunches) or those equipped with short triangular haunches. However, little was mentioned in literature or codes of practice about the behavior of tapered- haunched connections. This was in spite of their extensive use in medium-to-large span steel frames to develop more economic design and aesthetically pleasing views. In this paper, the behavior of tapered-haunched connections was investigated using the finite element method. The general-purpose finite element program, ANSYS was utilized in the analysis incorporating material nonlinearity and geometric imperfections to capture the interaction of yielding and buckling on the different failure modes of such connections. The magnitude of geometric imperfections was based on the allowable limit stipulated by the Egyptian Code of practice. Flow of stresses, yielding ...
Journal of Engineering and Applied Science
Web crippling of un-stiffened cold-formed channels, CFC, is rather complex due to many factors su... more Web crippling of un-stiffened cold-formed channels, CFC, is rather complex due to many factors such as: high stress gradients at applied loads, web buckling, and local web yielding. The analysis of CFC subjected to concentrated loads was conducted herein by the finite element method incorporating geometric and material non-linearities. Unlike current design rules that underestimated test results by more than 35%, the numerical solution compared well with test results. The analysis conducted herein revealed that web crippling capacity was essentially governed by local web yielding. However, web buckling governed the behavior at some cases when the two flanges were loaded and/or when the inside bend radius was reduced and web slenderness was increased. On the other hand, the web capacity for end loading cases was less than that for interior loading cases by 50% on average, whereas loading two flanges reduced the web capacity by 8% compared to loading one flange. A new set of design ru...
Journal of Engineering and Applied Science
Axial compressive strength of short concrete filled steel tubes, CFT, is at least equal to the su... more Axial compressive strength of short concrete filled steel tubes, CFT, is at least equal to the sum of the strengths of its components. Recent experimental and analytical research work revealed that the compressive strength of CFT could exceed the sum of its components strengths due to confinement effect of the steel tube surrounding the concrete core. In this work, the finite element analysis of short CFT subjected to axial loading was conducted using the general-purpose finite element program, ANSYS. The analysis was verified by comparison to test results published in the literature. An extensive parametric analysis was conducted to investigate the effect of steel tube slenderness ratio, concrete compressive strength, and steel tube yield strength on compressive strength of CFT. The analysis revealed that the compressive strength of concrete core might increase by 68% whereas the overall compressive strength of CFT might exceed the sum of its components strength by 14% due to confi...
Journal of Engineering and Applied Science
The finite element analysis of transversally stiffened web panels presented in previous research ... more The finite element analysis of transversally stiffened web panels presented in previous research works revealed some discrepancies between current design rules adopted by the AISC specifications and the behavior obtained from the numerical solution. Based on the assumption of geometrically perfect web stiffened by adequately rigid stiffeners, it was revealed that the AISC design rules underestimate the elastic buckling strength and overestimate the post-buckling strength of web panels. Unlike current design rules, a new set of design rules were proposed herein for transversally stiffened web panels to account for the rotational restraint provided by flanges to web and to account for the effect of through thickness bending stresses on the post-buckling strength.
Experimental and analytical research work that was conducted on unstiffened triangular bracket pl... more Experimental and analytical research work that was conducted on unstiffened triangular bracket plates showed that there are many sources of complexities in this type of connections. Unlike analytical analysis that was concerned with elastic buckling, experimental research indicated that yielding along the free edge usually takes place prior to buckling and that the connection possesses a significant amount of post buckling strength. An expression relating the average stress on the loaded edge to the maximum stress along the free edge was based on analytical work and revised by test results to establish the connection carrying load capacity. A limiting value for the bracket plate width-to-thickness ratio was established to prevent plate buckling. In this paper, a finite element model was established for the connection incorporating geometric and material imperfections. Critical and limit load obtained was compared to conventional design method. Stress distribution in welds and contac...
Design Engineering, Jul 16, 2021
Scientific Reports
The process of optimizing building designs requires developing several architectural and structur... more The process of optimizing building designs requires developing several architectural and structural layout alternatives. Traditionally, limited number of design iterations can be conducted manually, which is time consuming and results in non-optimum designs in terms of limited functionality or high costs. The goal of this research is to develop an advanced Building Information Modeling (BIM) model for automating and optimizing design of building layouts and structural elements to reach minimum construction cost while abiding by the functionality constraints of the architectural design. The developed model integrates concepts from structural design, BIM modeling, and computer programming into one advanced optimization framework. The model was tested and validated in 11 case studies and is found to reduce the structural materials cost by up to 15% per floor without compromising the defined space requirements.
Lecture notes in civil engineering, Jun 17, 2022
Steel and Composite Structures, 2019
World Academy of Science, Engineering and Technology, International Journal of Civil, Environmental, Structural, Construction and Architectural Engineering, 2017
Plate girders are used as an alternative in construction when hot rolled I-shaped beams show poor... more Plate girders are used as an alternative in construction when hot rolled I-shaped beams show poor strength or do not meet design requirements. Under high bending moments and shear forces, it is more efficient to use tapered plate girders. Current design codes lack specific design rules to estimate shear strength of plate girders with tapered web. The aim of this research is to investigate the elastic buckling and ultimate shear strengths of tapered end web panels in plate girders. More than two hundred detailed finite element models of plate girders with tapered end web panels are constructed and analyzed to cover a wide range of geometric parameters including: aspect ratio of end web panel, depth–to-thickness ratio of end web plate, inertia of intermediate stiffeners, and angle of tapering. Upon validation of the numerical solution, numerical results are used to establish a mathematical expression for the ultimate shear strength of prismatic and tapered end web panels. Design requi...
Cleaner Engineering and Technology
Experimental and analytical research work that was conducted on unstiffened triangular bracket pl... more Experimental and analytical research work that was conducted on unstiffened triangular bracket plates showed that there are many sources of complexities in this type of connections. Unlike analytical analysis that was concerned with elastic buckling, experimental research indicated that yielding along the free edge usually takes place prior to buckling and that the connection possesses a significant amount of post buckling strength. An expression relating the average stress on the loaded edge to the maximum stress along the free edge was based on analytical work and revised by test results to establish the connection carrying load capacity. A limiting value for the bracket plate width-to-thickness ratio was established to prevent plate buckling. In this paper, a finite element model was established for the connection incorporating geometric and material imperfections. Critical and limit load obtained was compared to conventional design method. Stress distribution in welds and contact stresses between bracket and beam were evaluated and compared to theoretical assumptions. Effect of triangular plate thickness and aspect ratio on connection behavior was investigated. It was shown that the design method based on previous analytical research work is conservative. The connection possesses a significant amount of post-buckling strength such that the limit load is almost twice the critical load.
Journal of Constructional Steel Research
Journal of Al-Azhar University Engineering Sector
There is a lack of study concerning the torsional loading effect on the flexural response of colu... more There is a lack of study concerning the torsional loading effect on the flexural response of column base especially cyclic behavior under combined torsional-flexural loading; many unknowns exist on this topic. A study for the flexural performance of the base connection for C-bent column subjected to seismic in the traffic direction is necessary to address the effect of the complex combination of cyclic flexural-torsional action on such a type of connection; for this purpose an extensive numerical parametric study was conducted to evaluate the flexural performance of the fixed base connection of C-bent bridge pier against combined cyclic bending and torsional loading following SAC phase II protocol. After verifying results with previous experimental works a Finite Element Analysis (FEA) using Strand7 is performed for Finite Element Models (FEM) which simulates force transfer at major contact interfaces in the connection, and a total of six base plate connection sub-assemblages with variable base plate thicknesses (three for stiffened connection and three for un-stiffened connection) anchored by 10 bolts, were configured and analyzed to support double cantilever pier subjected to eleven loading schemes that reflect different pairs of gravity moment and axial loads along with cyclic loading in the traffic direction eccentric from pier center of rigidity to guarantee the application of combined flexural-torsional action on the base connection. The study provided a curves for the following performance terms; strength (yield moment), deformation (yield curvature), curvature ductility, and stiffness (rotational flexural stiffness); the seismic flexural performance of the base connection under the previously mentioned loading package was evaluated by plotting the variation of the mentioned terms against the parametric values of the base plate thickness for different loading condition considered in the analysis. The study revealed that the state of gravity load weather it is concentric or eccentric has a great impact on the connection yield strength and deformation, further the level of eccentricity of the applied gravity loads has a significant impact on the connection stiffness, FLEXURAL BEHAVIOR OF BASE CONNECTION OF C-BENT COLUMN UNDER COMBINED CYCLIC BENDING-TORSIONAL LOADING more over increasing base plate thickness affect deformation capacity, and strength however with less impact on the strength and remarkable impact on the deformation, study also provided the effect of adding stiffeners to the connection, which enhanced the base fixation rigidity, however in turn of that curvature ductility has suffered noticeable reduction, in the same context curvature ductility is strongly deteriorated when the torsional stresses are dominant.
Journal of Al-Azhar University Engineering Sector
There is a lack of study concerning the torsional effect on the torsional response of column base... more There is a lack of study concerning the torsional effect on the torsional response of column base especially cyclic behavior under combined torsional-flexural loading; many unknowns exist on this topic. A study for the torsional performance of the base connection for C-bent column subjected to seismic in the traffic direction is necessary to address the effect of the complex combination of cyclic flexural-torsional action on such a type of connection; for this purpose an extensive numerical parametric study was conducted to evaluate the torsional performance of the fixed base connection of C-bent bridge pier against combined cyclic bending and torsional loading following SAC phase II protocol. After verifying results with previous experimental works a Finite Element Analysis (FEA) using Strand7 is performed for Finite Element Models (FEM) which simulates force transfer at major contact interfaces in the connection, and a total of six base plate connection sub-assemblages with variable base plate thicknesses (three for stiffened connection and three for un-stiffened connection) anchored by 10 bolts, were configured and analyzed to support double cantilever pier subjected to eleven loading schemes that reflect different pairs of gravity moment and axial loads along with cyclic loading in the traffic direction eccentric from pier center of rigidity to guarantee the application of combined flexural-torsional action on the base connection. The study provided a curves for the following performance terms; strength (ultimate torsion), deformation (ultimate twisting angle), and stiffness (torsional stiffness); the seismic torsional performance of the base connection under the previously mentioned loading package was evaluated by plotting the variation of the mentioned terms against the parametric values of the base plate thickness for different loading condition considered in the analysis.
Proceedings of the New Developments in Structural Engineering and Construction, 2013
ABSTRACT In this paper, the behavior of reinforced concrete beam-column connections strengthened ... more ABSTRACT In this paper, the behavior of reinforced concrete beam-column connections strengthened with Carbon Fiber Reinforced Plastic, CFRP, laminates was investigated by the finite element method. Numerical model of strengthened connections was verified by comparison to test results published in literature. A numerical investigation was conducted to assess the effect of CFRP strengthening configuration on the behavior of exterior beam-column connections belonging to a five-storey moment resisting frame. The load-deflection behavior, ultimate load, and ductility ratio of strengthened connections were compared to those of un-strengthened connections. It was shown that using full CFRP wraps on beams increased the ultimate load and stiffness of connections after first yielding of steel re-bars. Although strengthening connections with CFRP laminates altered their ductile failure mode to brittle failure by crushing of concrete, it was noticed that the application of CFRP wraps on beams extended to at least one-fifth of the beam span restored a significant portion of the connection ductility.
Journal of Engineering and Applied Science
Corner connections are crucial parts for the safety and adequate performance of steel frames. Ext... more Corner connections are crucial parts for the safety and adequate performance of steel frames. Extensive studies were made on the performance of square connections (without haunches) or those equipped with short triangular haunches. However, little was mentioned in literature or codes of practice about the behavior of tapered- haunched connections. This was in spite of their extensive use in medium-to-large span steel frames to develop more economic design and aesthetically pleasing views. In this paper, the behavior of tapered-haunched connections was investigated using the finite element method. The general-purpose finite element program, ANSYS was utilized in the analysis incorporating material nonlinearity and geometric imperfections to capture the interaction of yielding and buckling on the different failure modes of such connections. The magnitude of geometric imperfections was based on the allowable limit stipulated by the Egyptian Code of practice. Flow of stresses, yielding ...
Journal of Engineering and Applied Science
Web crippling of un-stiffened cold-formed channels, CFC, is rather complex due to many factors su... more Web crippling of un-stiffened cold-formed channels, CFC, is rather complex due to many factors such as: high stress gradients at applied loads, web buckling, and local web yielding. The analysis of CFC subjected to concentrated loads was conducted herein by the finite element method incorporating geometric and material non-linearities. Unlike current design rules that underestimated test results by more than 35%, the numerical solution compared well with test results. The analysis conducted herein revealed that web crippling capacity was essentially governed by local web yielding. However, web buckling governed the behavior at some cases when the two flanges were loaded and/or when the inside bend radius was reduced and web slenderness was increased. On the other hand, the web capacity for end loading cases was less than that for interior loading cases by 50% on average, whereas loading two flanges reduced the web capacity by 8% compared to loading one flange. A new set of design ru...
Journal of Engineering and Applied Science
Axial compressive strength of short concrete filled steel tubes, CFT, is at least equal to the su... more Axial compressive strength of short concrete filled steel tubes, CFT, is at least equal to the sum of the strengths of its components. Recent experimental and analytical research work revealed that the compressive strength of CFT could exceed the sum of its components strengths due to confinement effect of the steel tube surrounding the concrete core. In this work, the finite element analysis of short CFT subjected to axial loading was conducted using the general-purpose finite element program, ANSYS. The analysis was verified by comparison to test results published in the literature. An extensive parametric analysis was conducted to investigate the effect of steel tube slenderness ratio, concrete compressive strength, and steel tube yield strength on compressive strength of CFT. The analysis revealed that the compressive strength of concrete core might increase by 68% whereas the overall compressive strength of CFT might exceed the sum of its components strength by 14% due to confi...
Journal of Engineering and Applied Science
The finite element analysis of transversally stiffened web panels presented in previous research ... more The finite element analysis of transversally stiffened web panels presented in previous research works revealed some discrepancies between current design rules adopted by the AISC specifications and the behavior obtained from the numerical solution. Based on the assumption of geometrically perfect web stiffened by adequately rigid stiffeners, it was revealed that the AISC design rules underestimate the elastic buckling strength and overestimate the post-buckling strength of web panels. Unlike current design rules, a new set of design rules were proposed herein for transversally stiffened web panels to account for the rotational restraint provided by flanges to web and to account for the effect of through thickness bending stresses on the post-buckling strength.
Experimental and analytical research work that was conducted on unstiffened triangular bracket pl... more Experimental and analytical research work that was conducted on unstiffened triangular bracket plates showed that there are many sources of complexities in this type of connections. Unlike analytical analysis that was concerned with elastic buckling, experimental research indicated that yielding along the free edge usually takes place prior to buckling and that the connection possesses a significant amount of post buckling strength. An expression relating the average stress on the loaded edge to the maximum stress along the free edge was based on analytical work and revised by test results to establish the connection carrying load capacity. A limiting value for the bracket plate width-to-thickness ratio was established to prevent plate buckling. In this paper, a finite element model was established for the connection incorporating geometric and material imperfections. Critical and limit load obtained was compared to conventional design method. Stress distribution in welds and contac...