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Prof. Elsayed Fathallah
7Department of Civil Engineering, Military Technical College, Cairo11865, Egypt

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Research Keywords & Expertise

0 ANSYS
0 Optimization
0 underwater explosion
0 composite pressure hul
0 Buoyancy factor

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Optimization
ANSYS
Buoyancy factor
underwater explosion

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Journal article
Published: 03 August 2020 in Applied Sciences
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The most important problems confronted by designers of floating structures are minimizing weight and increasing payload to get proper resistance to the applied loads. In the present study, the structural performance of a ferry is analyzed using both metallic and composite materials as a result of the dynamic load of the Military Load Capacity (MLC) 70 (tank load). The model is composed of sixteen floating pontoons. Finite element simulation and dynamic analysis were performed using ANSYS software (analysis system software), considering a moving MLC70 (tank load). Both concentric and eccentric cases of loading are considered. Draft, deformation, and stresses are obtained and investigated. For the steel ferry, the von-Mises stresses are investigated, while for the composite ferry, the maximum principal stresses are investigated. Furthermore, buckling analysis is performed on the composite ferry and the buckling load factor is determined. The results of the dynamic analysis illustrated that the transverse eccentricity of the moving tank MLC70 must not exceed 0.5 m for a steel ferry while it may reach up to 1.5 m for the composite ferry. This research can also be a useful tool in the design of floating composite and steel ferries.

ACS Style

Mohamed N. Lotfy; Yasser A. Khalifa; Abdelrahim K. Dessouki; Elsayed Fathallah. Dynamic Behavior of Steel and Composite Ferry Subjected to Transverse Eccentric Moving Load Using Finite Element Analysis. Applied Sciences 2020, 10, 5367 .

AMA Style

Mohamed N. Lotfy, Yasser A. Khalifa, Abdelrahim K. Dessouki, Elsayed Fathallah. Dynamic Behavior of Steel and Composite Ferry Subjected to Transverse Eccentric Moving Load Using Finite Element Analysis. Applied Sciences. 2020; 10 (15):5367.

Chicago/Turabian Style

Mohamed N. Lotfy; Yasser A. Khalifa; Abdelrahim K. Dessouki; Elsayed Fathallah. 2020. "Dynamic Behavior of Steel and Composite Ferry Subjected to Transverse Eccentric Moving Load Using Finite Element Analysis." Applied Sciences 10, no. 15: 5367.

Journal article
Published: 20 March 2020 in Applied Sciences
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The need for building protection against blast loads is a crucial issue nowadays due to the escalating threat of terrorist attacks, which affect people’s lives and critical structures. Consequently, design of protective panels to segregate building façades from the effect of a nearby explosion is required. Such design mainly depends on the ability of protective panels to mitigate and diffract the blast wave before reaching building façades. Five protective panel models with different designs, referred to as the Combined Protection System (CPS), are introduced in this paper. The main objective of this research was to achieve a design that could sustain a blast load with minimum plastic deformations. The introduced CPS designs included two steel plates linked by connector plates. The CPS dimensions were 3 m × 3 m × 0.35 m, representing length, width, and height, respectively. After that, the successful panel design was supported by placing these panels onto a masonry wall in different configurations. The protective panels were tested against 50 kg of trinitrotoluene (TNT) with a standoff distance of one meter. The final run of the optimum model was carried out using a blast load equivalent to 500 kg of TNT. The air–structure interactions were simulated using finite element analysis software called “ANSYS AUTODYN”, where the deformation of the panel was the governing parameter to evaluate the behavior of different designs. The analysis showed minimum deformation of the CPS design with vertical and horizontal connecting plates in a masonry wall distanced at 500 mm from the panel. However, the other designs showed promising results, which could make them suitable for critical structural protection on different scales.

ACS Style

Ageel Alogla; Mahmoud Helal; Mohamed Mokbel Elshafey; Elsayed Fathallah. Numerical Analysis for Critical Structures Protection against Blast Loading Using Metallic Panels. Applied Sciences 2020, 10, 2121 .

AMA Style

Ageel Alogla, Mahmoud Helal, Mohamed Mokbel Elshafey, Elsayed Fathallah. Numerical Analysis for Critical Structures Protection against Blast Loading Using Metallic Panels. Applied Sciences. 2020; 10 (6):2121.

Chicago/Turabian Style

Ageel Alogla; Mahmoud Helal; Mohamed Mokbel Elshafey; Elsayed Fathallah. 2020. "Numerical Analysis for Critical Structures Protection against Blast Loading Using Metallic Panels." Applied Sciences 10, no. 6: 2121.

Journal article
Published: 02 December 2019 in Materials Testing
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Pressure hulls are one of the keys in the design of submarines. In order to improve the accuracy and efficiency of pressure hull structure, methods of optimizing it were studied. In the present study, an overview of the multi-objective optimization of intersecting cross elliptical pressure hulls (ICEPH) with and without the core layer under hydrostatic pressure was investigated in order to maximize buckling load capacity (λ) and minimize the buoyancy factor (B.F) of the ICEPH according to the design requirements. Five models were built, four composite models constructed from boron/epoxy (B(4)/5505) and carbon/epoxy composite (USN-150) with and without core layer. The fifth is a reference metallic model constructed from HY100. Criteria regarding failure for both composite and metal shells are considered as indications of optimization. Both Tsai-Wu and maximum stress failure criteria were employed to check the composite failure. The modeling and the multi-objective optimization were performed using ANSYS parametric design language (APDL) in order to determine mass, critical buckling load, and failure criteria. The results illustrated that carbon fiber-epoxy composite (USN-150) with a core layer is preferred for obtaining minimum weight, with an improvement ratio (IR) 64.314 % superior to that of a metallic pressure hull. By contrast, (boron/epoxy B(4)/5505) without a core layer is preferred to obtain a maximum buckling load.

ACS Style

Mahmoud Helal; Elsayed Fathallah. Multi-objective optimization of an intersecting elliptical pressure hull as a means of buckling pressure maximizing and weight minimization. Materials Testing 2019, 61, 1179 -1191.

AMA Style

Mahmoud Helal, Elsayed Fathallah. Multi-objective optimization of an intersecting elliptical pressure hull as a means of buckling pressure maximizing and weight minimization. Materials Testing. 2019; 61 (12):1179-1191.

Chicago/Turabian Style

Mahmoud Helal; Elsayed Fathallah. 2019. "Multi-objective optimization of an intersecting elliptical pressure hull as a means of buckling pressure maximizing and weight minimization." Materials Testing 61, no. 12: 1179-1191.

Journal article
Published: 22 October 2019 in Journal of Marine Science and Engineering
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The pressure hull is the primary element of submarine, which withstands diving pressure and provides essential capacity for electronic systems and buoyancy. This study presents a numerical analysis and design optimization of sandwich composite deep submarine pressure hull using finite element modeling technique. This study aims to minimize buoyancy factor and maximize deck area and buckling strength factors. The collapse depth is taken as a base in the pressure hull design. The pressure hull has been analyzed using two composite materials, T700/Epoxy and B(4)5505/Epoxy, to form the upper and lower faces of the sandwich composite deep submarine pressure hull. The laminated control surface is optimized for the first ply failure index (FI) considering both Tsai–Wu and maximum stress failure criteria. The results obtained emphasize an important fact that the presence of core layer in sandwich composite pressure hull is not always more efficient. The use of sandwich in the design of composite deep submarine pressure hull at extreme depths is not a safe option. Additionally, the core thickness plays a minor role in the design of composite deep submarine pressure hull. The outcome of an optimization at extreme depths illustrates that the upper and lower faces become thicker and the core thickness becomes thinner. However, at shallow-to-moderate depths, it is recommended to use sandwich composite with a thick core to resist the shell buckling of composite submarine pressure hull.

ACS Style

Mahmoud Helal; Huinan Huang; Defu Wang; Elsayed Fathallah. Numerical Analysis of Sandwich Composite Deep Submarine Pressure Hull Considering Failure Criteria. Journal of Marine Science and Engineering 2019, 7, 377 .

AMA Style

Mahmoud Helal, Huinan Huang, Defu Wang, Elsayed Fathallah. Numerical Analysis of Sandwich Composite Deep Submarine Pressure Hull Considering Failure Criteria. Journal of Marine Science and Engineering. 2019; 7 (10):377.

Chicago/Turabian Style

Mahmoud Helal; Huinan Huang; Defu Wang; Elsayed Fathallah. 2019. "Numerical Analysis of Sandwich Composite Deep Submarine Pressure Hull Considering Failure Criteria." Journal of Marine Science and Engineering 7, no. 10: 377.

Journal article
Published: 23 August 2019 in Applied Sciences
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Among the most important problems confronted by designers of submarines is to minimize the weight, increase the payload, and enhance the strength of pressure hull in order to sustain the hydrostatic pressure and underwater explosions (UNDEX). In this study, a Multiple Intersecting Cross Elliptical Pressure Hull (MICEPH) subjected to hydrostatic pressure was first optimized to increase the payload according to the design requirements. Thereafter, according to the optimum design results, a numerical analysis for the fluid structure interaction (FSI) phenomena and UNDEX were implemented using nonlinear finite element code ABAQUS/Explicit. The propagation of shock waves through the MICEPH was analyzed and the response modes (breathing, accordion and whipping) were discussed. Furthermore, the acceleration, displacement and failure index time histories at different locations were presented. The results showed that the greatest acceleration occurred in the athwart direction, followed by the vertical and longitudinal directions. Additionally, the first bubble pulse has a major effect on athwart acceleration. Moreover, the analysis can be effectively used to predict and calculate the failure indices of pressure hull. Additionally, it provides an efficient method that reasonably captures the dynamic response of a pressure hull subjected to UNDEX.

ACS Style

Mahmoud Helal; Huinan Huang; Elsayed Fathallah; Defu Wang; Mohamed Mokbel Elshafey; Mohamed Ali. Numerical Analysis and Dynamic Response of Optimized Composite Cross Elliptical Pressure Hull Subject to Non-Contact Underwater Blast Loading. Applied Sciences 2019, 9, 3489 .

AMA Style

Mahmoud Helal, Huinan Huang, Elsayed Fathallah, Defu Wang, Mohamed Mokbel Elshafey, Mohamed Ali. Numerical Analysis and Dynamic Response of Optimized Composite Cross Elliptical Pressure Hull Subject to Non-Contact Underwater Blast Loading. Applied Sciences. 2019; 9 (17):3489.

Chicago/Turabian Style

Mahmoud Helal; Huinan Huang; Elsayed Fathallah; Defu Wang; Mohamed Mokbel Elshafey; Mohamed Ali. 2019. "Numerical Analysis and Dynamic Response of Optimized Composite Cross Elliptical Pressure Hull Subject to Non-Contact Underwater Blast Loading." Applied Sciences 9, no. 17: 3489.

Journal article
Published: 01 May 2019 in Materials Science Forum
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Excellent mechanical behavior and low density of composite materials make them candidates to replace metals for many underwater applications. This paper presents a comprehensive study about the multi-objective optimization of composite pressure hull subjected to hydrostatic pressure to minimize the weight of the pressure hull and maximize the buckling load capacity according to the design requirements. Two models were constructed, one model constructed from Carbon/Epoxy composite (USN-150), the other model is metallic pressure hull constructed from HY100. The analysis and the optimization process were completely performed using ANSYS Parametric Design Language (APDL). Tsai-Wu failure criterion was incorporated in the optimization process. The results obtained emphasize that, the submarine constructed from Carbon/Epoxy composite (USN-150) is better than the submarine constructed from HY100. Finally, an optimized model with an optimum pattern of fiber orientations was presented. Hopefully, the results may provide a valuable insight for the future of designing composite underwater vehicles.

ACS Style

Elsayed Fathallah. Finite Element Modelling and Multi-Objective Optimization of Composite Submarine Pressure Hull Subjected to Hydrostatic Pressure. Materials Science Forum 2019, 953, 53 -58.

AMA Style

Elsayed Fathallah. Finite Element Modelling and Multi-Objective Optimization of Composite Submarine Pressure Hull Subjected to Hydrostatic Pressure. Materials Science Forum. 2019; 953 ():53-58.

Chicago/Turabian Style

Elsayed Fathallah. 2019. "Finite Element Modelling and Multi-Objective Optimization of Composite Submarine Pressure Hull Subjected to Hydrostatic Pressure." Materials Science Forum 953, no. : 53-58.

Original article
Published: 01 April 2017 in Journal of Engineering Science and Military Technologies
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ACS Style

Ageel Alogla; Mahmoud Helal; Abdal Allah Abdal Allah; Elsayed Fathallah. Design Optimization of a Flexible Hinge Compliant Micro-Gripper Mechanism with Parallel Movement Arms Using Pseudo-Rigid-Body Model. Journal of Engineering Science and Military Technologies 2017, 17, 1 -18.

AMA Style

Ageel Alogla, Mahmoud Helal, Abdal Allah Abdal Allah, Elsayed Fathallah. Design Optimization of a Flexible Hinge Compliant Micro-Gripper Mechanism with Parallel Movement Arms Using Pseudo-Rigid-Body Model. Journal of Engineering Science and Military Technologies. 2017; 17 (17):1-18.

Chicago/Turabian Style

Ageel Alogla; Mahmoud Helal; Abdal Allah Abdal Allah; Elsayed Fathallah. 2017. "Design Optimization of a Flexible Hinge Compliant Micro-Gripper Mechanism with Parallel Movement Arms Using Pseudo-Rigid-Body Model." Journal of Engineering Science and Military Technologies 17, no. 17: 1-18.

Original article
Published: 01 April 2017 in International Conference on Aerospace Sciences and Aviation Technology
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ACS Style

Ageel Alogla; Mahmoud Helal; Abdal Allah Abdal Allah; Elsayed Fathallah. Design Optimization of a Flexible Hinge Compliant Micro icro-Gripper ripper Mechanism with Parallel Movement Arms Using Pseudo-Rigid -Body Model. International Conference on Aerospace Sciences and Aviation Technology 2017, 17, 1 -18.

AMA Style

Ageel Alogla, Mahmoud Helal, Abdal Allah Abdal Allah, Elsayed Fathallah. Design Optimization of a Flexible Hinge Compliant Micro icro-Gripper ripper Mechanism with Parallel Movement Arms Using Pseudo-Rigid -Body Model. International Conference on Aerospace Sciences and Aviation Technology. 2017; 17 (AEROSPACE):1-18.

Chicago/Turabian Style

Ageel Alogla; Mahmoud Helal; Abdal Allah Abdal Allah; Elsayed Fathallah. 2017. "Design Optimization of a Flexible Hinge Compliant Micro icro-Gripper ripper Mechanism with Parallel Movement Arms Using Pseudo-Rigid -Body Model." International Conference on Aerospace Sciences and Aviation Technology 17, no. AEROSPACE: 1-18.

Journal article
Published: 01 March 2015 in Composite Structures
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ACS Style

Elsayed Fathallah; Hui Qi; Lili Tong; Mahmoud Helal. Numerical investigation of the dynamic response of optimized composite elliptical submersible pressure hull subjected to non-contact underwater explosion. Composite Structures 2015, 121, 121 -133.

AMA Style

Elsayed Fathallah, Hui Qi, Lili Tong, Mahmoud Helal. Numerical investigation of the dynamic response of optimized composite elliptical submersible pressure hull subjected to non-contact underwater explosion. Composite Structures. 2015; 121 ():121-133.

Chicago/Turabian Style

Elsayed Fathallah; Hui Qi; Lili Tong; Mahmoud Helal. 2015. "Numerical investigation of the dynamic response of optimized composite elliptical submersible pressure hull subjected to non-contact underwater explosion." Composite Structures 121, no. : 121-133.

Journal article
Published: 01 March 2015 in Composite Structures
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ACS Style

Elsayed Fathallah; Hui Qi; Lili Tong; Mahmoud Helal. Design optimization of lay-up and composite material system to achieve minimum buoyancy factor for composite elliptical submersible pressure hull. Composite Structures 2015, 121, 16 -26.

AMA Style

Elsayed Fathallah, Hui Qi, Lili Tong, Mahmoud Helal. Design optimization of lay-up and composite material system to achieve minimum buoyancy factor for composite elliptical submersible pressure hull. Composite Structures. 2015; 121 ():16-26.

Chicago/Turabian Style

Elsayed Fathallah; Hui Qi; Lili Tong; Mahmoud Helal. 2015. "Design optimization of lay-up and composite material system to achieve minimum buoyancy factor for composite elliptical submersible pressure hull." Composite Structures 121, no. : 16-26.

Research article
Published: 28 August 2014 in Advances in Materials Science and Engineering
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A numerical simulation has been carried out to examine the response of steel plates with different arrangement of stiffeners and subjected to noncontact underwater explosion (UNDEX) with different shock loads. Numerical analysis of the underwater explosion phenomena is implemented in the nonlinear finite element code ABAQUS/Explicit. The aim of this work is to enhance the dynamic response to resist UNDEX. Special emphasis is focused on the evolution of mid-point displacements. Further investigations have been performed to study the effects of including material damping and the rate-dependant material properties at different shock loads. The results indicate that stiffeners configurations and shock loads affect greatly the overall performance of steel plates and sensitive to the materials data. Also, the numerical results can be used to obtain design guidelines of floating structures to enhance resistance of underwater shock damage, since explosive tests are costly and dangerous.

ACS Style

Elsayed Fathallah; Hui Qi; Lili Tong; Mahmoud Helal. Numerical Simulation and Response of Stiffened Plates Subjected to Noncontact Underwater Explosion. Advances in Materials Science and Engineering 2014, 2014, 1 -17.

AMA Style

Elsayed Fathallah, Hui Qi, Lili Tong, Mahmoud Helal. Numerical Simulation and Response of Stiffened Plates Subjected to Noncontact Underwater Explosion. Advances in Materials Science and Engineering. 2014; 2014 ():1-17.

Chicago/Turabian Style

Elsayed Fathallah; Hui Qi; Lili Tong; Mahmoud Helal. 2014. "Numerical Simulation and Response of Stiffened Plates Subjected to Noncontact Underwater Explosion." Advances in Materials Science and Engineering 2014, no. : 1-17.

Journal article
Published: 01 January 2014 in Advances in Mechanical Engineering
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The design of deep submersible pressure hull's structural is one of the core technologies of submersible development of human history. Submersible pressure hulls with fiber-reinforced multilayer constructions have been developed in the recent years as substitutes for classical metallic ring-stiffened pressure hulls; strength and stability are its top priority. This paper investigates the optimum design of a composite elliptical deep-submerged pressure hull under hydrostatic pressure to minimize the buoyancy factor of the submersible pressure hull under constraints on the failure criteria and the buckling strength of the hulls to reach the maximum operating depth. The thickness and the fiber orientation angles in each layer, the radii of the ellipse, and stringers dimensions were taken as design variables and determined in the design process. The optimization procedures are performed using commercial finite element analysis software ANSYS. Additionally, a sensitivity analysis is performed to study the influence of the design variables on the structural optimum design. Results of this study provide a valuable reference for designers of underwater vehicles.

ACS Style

Elsayed Fathallah; Hui Qi; Lili Tong; Mahmoud Helal. Design Optimization of Composite Elliptical Deep-Submersible Pressure Hull for Minimizing the Buoyancy Factor. Advances in Mechanical Engineering 2014, 6, 1 .

AMA Style

Elsayed Fathallah, Hui Qi, Lili Tong, Mahmoud Helal. Design Optimization of Composite Elliptical Deep-Submersible Pressure Hull for Minimizing the Buoyancy Factor. Advances in Mechanical Engineering. 2014; 6 ():1.

Chicago/Turabian Style

Elsayed Fathallah; Hui Qi; Lili Tong; Mahmoud Helal. 2014. "Design Optimization of Composite Elliptical Deep-Submersible Pressure Hull for Minimizing the Buoyancy Factor." Advances in Mechanical Engineering 6, no. : 1.