Browsing by Author "Mahmoud, Ashraf Mohamed"

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Finite element modeling for RC hollow columns wrapped with FRP laminates
(TRANS TECH PUBLICATIONS LTD, 2011) Mahmoud, Ashraf Mohamed
A finite element reinforced concrete model has been analyzed by the author with Ansys v.9 finite element program for both unstrengthened and CFRP-strengthened hollow columns using solid65 concrete element, its size 24x26x24 mm and Link8 discrete steel distribution element. The CFRP has been modeled using Solid46 element, which has orthotropic properties. The deflection results have been compared with an experimental and other finite element model which are performed by Lignola [6], in which using Tno Diana v. 9.1 finite element program for modeling concrete using three-dimensional solid brick element type Chx60, steel using embedded reinforcement truss element and CFRP using three-node plane bonded element. These results show that the author's model is much better than the Lignola's [6] model comparing with the experimental one. A parametric study has been done on the proposed model for obtaining the effect of using the GFRP instead of the CFRP in column strengthening by comparing the failure loads and the concrete and steel properties at failure. This study show a reduction in the failure load values by an amount 0.6 to 2.8% when using GFRP, indicating that the CFRP is more preferable in strengthening of the hollow column than the GFR
Finite element modeling of steel concrete beam considering double composite action
(ELSEVIER SCIENCE BV, 2016) Mahmoud, Ashraf Mohamed
Steel concrete composite construction has gained wide acceptance as an alternative to pure steel or concrete construction. Ansys 11 computer program has been used to develop a three-dimensional nonlinear finite element model in order to investigate the fracture behaviors of continuous double steel-concrete composite beams, with emphasis on the beam slab interface. Three beam models with varying number of the head studs have been addressed. The associated constitutive results such as the ultimate loads, the maximum deflections, the interface slip and slip strain values are presented. A parametric study has been carried out in order to investigate the effect of some parameters on their fracture capabilities, such as steel beam height, lower slab thickness and length, studs diameter and arrangement method. By comparing these results with the available experimental data, the proposed model is found to be capable of analyzing steel-concrete composite beams to an acceptable accuracy. (C) 2015 Faculty of Engineering, Ain Shams University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
`Nonlinear analysis of green house systems
(ELSEVIER SCIENCE BV, 2012-12) Mahmoud, Ashraf Mohamed
A numerical procedure based on energy minimization has been extended herein to analyze a system of two dimensional cable trusses called green houses. The joint displacements and member forces results are obtained and compared with a finite element computer program and previously published thesis. This study was done on three cases of span lengths. It was found that the effect of increasing the pylon height (H) on the displacements and member forces is less than the case when reducing the value of (H). It was found also that the choice of the span length L = 16 m is more preferable than the others, because the rate of change of displacements and end forces was minimal compared with the others. It was also observed that when the number of spans is increased, the effect of the variation of the pylon height on the cable truss total weight will be vanished. (C) 2012 Ain Shams University. Production and hosting by Elsevier B.V. All rights reserved.