Nile Valley University Digital Repository مستودع جامعة وادي النيل الرقميhttp://hdl.handle.net/123456789/12018-06-19T09:00:00Z2018-06-19T09:00:00ZLarge Deformation Finite Element Analysis of Shell StructuresFathelrahman M Adam, فتح الرحمن محمد ادمA/ERAHMAN ELZUBIER MOHAMED, عبد الرحمن الزبير محمدhttp://hdl.handle.net/123456789/20182018-06-14T08:59:56Z2018-06-14T00:00:00ZLarge Deformation Finite Element Analysis of Shell Structures
Fathelrahman M Adam, فتح الرحمن محمد ادم; A/ERAHMAN ELZUBIER MOHAMED, عبد الرحمن الزبير محمد
A finite element formulation is presented for conducting large deformation analysis of
shells. The element adopted herein is a degenerated three-dimensional 8-nodes
isoparametric finite element. Derivations of the nonlinear geometric element stiffness
matrices were made on the basis of total lagrangian formulation by using both
geometric strains (Engineering Strains) and Green’s stains. The formulations were
implemented into a nonlinear finite element program. The nonlinear equilibrium
equations are solved by combined incremental load and Newton-Raphson method.
Examples are presented for the analysis of cylindrical shells. Agreement with existing
solutions is generally good.
2018-06-14T00:00:00ZDESIGN OPTIMIZATION OF REINFORCED CONCRETE BEAMS USING ARTIFICIAL NEURAL NETWORKFathelrahman M Adam, فتح الرحمن محمد ادمAbdelrahman E. Mohamed, عبد الرحمن محمدSara A. Babiker, سارة أ. بابكرhttp://hdl.handle.net/123456789/20172018-06-14T08:52:20Z2012-10-01T00:00:00ZDESIGN OPTIMIZATION OF REINFORCED CONCRETE BEAMS USING ARTIFICIAL NEURAL NETWORK
Fathelrahman M Adam, فتح الرحمن محمد ادم; Abdelrahman E. Mohamed, عبد الرحمن محمد; Sara A. Babiker, سارة أ. بابكر
This paper presents an Artificial Neural Networks (ANN) model for the cost optimization of simply supported beams designed according to the requirements of the ACI 318-08 code. The model formulation includes the cost of concrete, the cost of reinforcement and the cost of formwork. A simply supported beam was designed adopting variable cross sections, in order to demonstrate the model capabilities in optimizing the beam design. Computer models have been developed for the structural design optimization of reinforced concrete simple beams using NEURO SHELL-2 software. The results obtained were compared with the results obtained by using the classical optimization model, developed in the well known Excel software spreadsheet which uses the generalized reduced gradient (GRG). The results obtained using the two modes are in good agreement
International Journal of Engineering Inventions
ISSN: 2278-7461, www.ijeijournal.com
Volume 1, Issue 8 (October2012) PP: 07-13
2012-10-01T00:00:00ZEvaluation of Engineering Stresses as the “Correct” Measure of “Physical” Stresses in Large Strain Geometrically Nonlinear ProblemsFathelrahman M Adam, فتح الرحمن محمد ادمMohmed, A. E.Akasha, N. M.http://hdl.handle.net/123456789/20162018-06-14T08:45:19Z2013-05-01T00:00:00ZEvaluation of Engineering Stresses as the “Correct” Measure of “Physical” Stresses in Large Strain Geometrically Nonlinear Problems
Fathelrahman M Adam, فتح الرحمن محمد ادم; Mohmed, A. E.; Akasha, N. M.
In this paper, Lagrangian formulations for geometric nonlinear plane stress/strain problems based on different stress measures are evaluated. A Total Lagrangian formulation based on the exact Engineering strains is developed. The 2ndPiola-Kirchhoff stresses based on the well known Green strains and the Engineering stresses based on the exact Engineering (geometric or conventional) strains obtained from Total Lagrangian formulations are compared with the true Cauchy stresses. The Engineering stresses based on the assumption of small shear strains are also compared with the above mentioned stresses. Geometric nonlinear Total Lagrangian formulations applied on two-dimensional elasticity using 4-node plane finite elements were used. The formulations were implemented into the finite element program (NUSAP). The solution of nonlinear equations was obtained by the Newton-Raphson method. The program was applied to obtain stresses for the different strain measures. The true Cauchy stresses were obtained by using the Logarithmic strains. The evaluation was based on comparing the results of three numerical examples. For moderate and large strains, the exact Engineering stresses are good measures of the correct physical stresses. Thus, these must be used when the stresses are required from a Total Lagrangian solution.
International Journal of Engineering Inventions
e-ISSN: 2278-7461, p-ISSN: 2319-6491
Volume 2, Issue 8 (May 2013) PP: 16-27
2013-05-01T00:00:00ZDegenerated Four Nodes Shell Element with Drilling Degree of FreedomMohamed, Abdelrahman. E.Adam, Fathelrahman M.Hassaballa, A. E.http://hdl.handle.net/123456789/20152018-06-14T08:37:40Z2013-08-01T00:00:00ZDegenerated Four Nodes Shell Element with Drilling Degree of Freedom
Mohamed, Abdelrahman. E.; Adam, Fathelrahman M.; Hassaballa, A. E.
A four node degenerated shell element with drilling degree of freedom is presented in this paper. The problem of zero stiffness that appears with using the drilling degree of freedom and causes singularity in the structure stiffness matrix is solved by employing, one of the recommended remedies. That is, adding a fictitious rotational stiffness using a penalty parameter (torsional constant) to control the solution to insure good element performance. Examples are presented including comparisons of torsional constant with the maximum displacements by using different mesh sizes, which results on selecting a value equal to one for the torsional constant is suitable value used to insure rapid convergence to true solution.
IOSR Journal of Engineering (IOSRJEN) e-ISSN: 2250-3021, p-ISSN: 2278-8719 Vol. 3, Issue 8 (August. 2013), ||V3 || PP 10-20
2013-08-01T00:00:00Z