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In-Place Analysis for Structural Integrity Assessment of Fixed Steel Offshore Platform

Research Abstract
In-place analysis for offshore platforms is essentially required to make proper design for new structures and true assessment for existing structures. The structural integrity of platform components under the maximum and minimum operating loads of environmental conditions is required for risk assessment and inspection plan development. In-place analyses have been executed to check that the structural member with all appurtenances has robustness and capability to support the applied loads in either storm condition or operating condition. A nonlinear finite element analysis is adopted for the platform structure above the seabed and the soil–pile–jacket interaction to estimate the in-place behavior of a typical fixed offshore platform. The analysis includes an interpretation of the dynamic design parameters based on the available site-specific data, together with foundation design recommendations for in-place loading conditions. The SACS software is utilized to calculate the natural frequencies, dynamic amplification factors, and the stresses at selected members, as well as their nodal displacements. The directions of environmental loads and water depth variations have important effects on the results of the in-place analysis behavior. The incidence angle of seismic waves is an essential parameter, where, for some crucial angles, the internal forces and the maximum deformations can be doubled or more in comparison with the ones corresponding to other, less crucial angles. Therefore, the incidence angle considerably affects the response quantities. The results confirm that the in-place analysis is quite essential for the reliable design of new offshore platforms and the assessment of existing offshore structures.
Research Authors
Shehata E. Abdel Raheem, Elsayed M. Abdel Aal, Aly G. A. Abdel Shafy, Mohamed F. M. Fahmy & Mohamed Omar
Research Department
Research Journal
Arabian Journal for Science and Engineering
Research Member
Research Pages
1-15
Research Publisher
Springer Nature
Research Rank
1
Research Vol
**(**)
Research Website
https://link.springer.com/article/10.1007/s13369-020-05200-3
Research Year
2021

In-Place Analysis for Structural Integrity Assessment of Fixed Steel Offshore Platform

Research Abstract
In-place analysis for offshore platforms is essentially required to make proper design for new structures and true assessment for existing structures. The structural integrity of platform components under the maximum and minimum operating loads of environmental conditions is required for risk assessment and inspection plan development. In-place analyses have been executed to check that the structural member with all appurtenances has robustness and capability to support the applied loads in either storm condition or operating condition. A nonlinear finite element analysis is adopted for the platform structure above the seabed and the soil–pile–jacket interaction to estimate the in-place behavior of a typical fixed offshore platform. The analysis includes an interpretation of the dynamic design parameters based on the available site-specific data, together with foundation design recommendations for in-place loading conditions. The SACS software is utilized to calculate the natural frequencies, dynamic amplification factors, and the stresses at selected members, as well as their nodal displacements. The directions of environmental loads and water depth variations have important effects on the results of the in-place analysis behavior. The incidence angle of seismic waves is an essential parameter, where, for some crucial angles, the internal forces and the maximum deformations can be doubled or more in comparison with the ones corresponding to other, less crucial angles. Therefore, the incidence angle considerably affects the response quantities. The results confirm that the in-place analysis is quite essential for the reliable design of new offshore platforms and the assessment of existing offshore structures.
Research Authors
Shehata E. Abdel Raheem, Elsayed M. Abdel Aal, Aly G. A. Abdel Shafy, Mohamed F. M. Fahmy & Mohamed Omar
Research Department
Research Journal
Arabian Journal for Science and Engineering
Research Member
Research Pages
1-15
Research Publisher
Springer Nature
Research Rank
1
Research Vol
**(**)
Research Website
https://link.springer.com/article/10.1007/s13369-020-05200-3
Research Year
2021

In-Place Analysis for Structural Integrity Assessment of Fixed Steel Offshore Platform

Research Abstract
In-place analysis for offshore platforms is essentially required to make proper design for new structures and true assessment for existing structures. The structural integrity of platform components under the maximum and minimum operating loads of environmental conditions is required for risk assessment and inspection plan development. In-place analyses have been executed to check that the structural member with all appurtenances has robustness and capability to support the applied loads in either storm condition or operating condition. A nonlinear finite element analysis is adopted for the platform structure above the seabed and the soil–pile–jacket interaction to estimate the in-place behavior of a typical fixed offshore platform. The analysis includes an interpretation of the dynamic design parameters based on the available site-specific data, together with foundation design recommendations for in-place loading conditions. The SACS software is utilized to calculate the natural frequencies, dynamic amplification factors, and the stresses at selected members, as well as their nodal displacements. The directions of environmental loads and water depth variations have important effects on the results of the in-place analysis behavior. The incidence angle of seismic waves is an essential parameter, where, for some crucial angles, the internal forces and the maximum deformations can be doubled or more in comparison with the ones corresponding to other, less crucial angles. Therefore, the incidence angle considerably affects the response quantities. The results confirm that the in-place analysis is quite essential for the reliable design of new offshore platforms and the assessment of existing offshore structures.
Research Authors
Shehata E. Abdel Raheem, Elsayed M. Abdel Aal, Aly G. A. Abdel Shafy, Mohamed F. M. Fahmy & Mohamed Omar
Research Department
Research Journal
Arabian Journal for Science and Engineering
Research Pages
1-15
Research Publisher
Springer Nature
Research Rank
1
Research Vol
**(**)
Research Website
https://link.springer.com/article/10.1007/s13369-020-05200-3
Research Year
2021

Seismic pounding between adjacent buildings considering soil-structure interaction

Research Abstract
In urban cities, buildings were built in the neighborhood, these buildings influence each other through structure-soil-structure interaction (SSSI) and seismic pounding due to limited separation distance in-between. Generally, the effects of the interaction between soil and structure are disregarded during seismic design and analysis of superstructure. However, the system of soil-base adversely changes structural behavior and response demands. Thus, the vibration characteristics plus the seismic response of a building are not able to be independent of those in adjacent buildings. The interaction between structure, soil, and structure investigates the action of the attendance of adjacent buildings to the others by the interaction effect of the sub-soil under dynamic disturbances. The main purpose of this research is to analyze the effects of SSSI and seismic pounding on the behavior of adjacent buildings. The response of a single structure or two adjacent structures with shallow raft base lying on soft soil are studied. Three dimensions finite element models are developed to investigate the effects of pounding; gap distance; conditions of soil; stories number; a mass of adjacent building and ground excitation frequency on the seismic responses and vibration characteristics of the structures. The variation in the story displacement, story shear, and story moment responses demands are studied to evaluate the presence effect of the adjacent buildings. Numerical results acquired using conditions of soil models are compared with the condition of fixed support and adjacent building models to a single building model. The peak responses of story displacement, story moment, and story shear are studied.
Research Authors

Shehata E Abdel Raheem, Tarek M.A. Alazrak, Aly G.A. AbdelShafy, Mohamed M. Ahmed and Yasser A.S. Gamal
Research Department
Research Journal
Earthquakes and Structures
Research Pages
55-70
Research Publisher
Techno-Press Publishers
Research Rank
1
Research Vol
20(1)
Research Website
http://www.techno-press.org/content/?page=article&journal=eas&volume=20&num=1&ordernum=5
Research Year
2021

Seismic pounding between adjacent buildings considering soil-structure interaction

Research Abstract
In urban cities, buildings were built in the neighborhood, these buildings influence each other through structure-soil-structure interaction (SSSI) and seismic pounding due to limited separation distance in-between. Generally, the effects of the interaction between soil and structure are disregarded during seismic design and analysis of superstructure. However, the system of soil-base adversely changes structural behavior and response demands. Thus, the vibration characteristics plus the seismic response of a building are not able to be independent of those in adjacent buildings. The interaction between structure, soil, and structure investigates the action of the attendance of adjacent buildings to the others by the interaction effect of the sub-soil under dynamic disturbances. The main purpose of this research is to analyze the effects of SSSI and seismic pounding on the behavior of adjacent buildings. The response of a single structure or two adjacent structures with shallow raft base lying on soft soil are studied. Three dimensions finite element models are developed to investigate the effects of pounding; gap distance; conditions of soil; stories number; a mass of adjacent building and ground excitation frequency on the seismic responses and vibration characteristics of the structures. The variation in the story displacement, story shear, and story moment responses demands are studied to evaluate the presence effect of the adjacent buildings. Numerical results acquired using conditions of soil models are compared with the condition of fixed support and adjacent building models to a single building model. The peak responses of story displacement, story moment, and story shear are studied.
Research Authors

Shehata E Abdel Raheem, Tarek M.A. Alazrak, Aly G.A. AbdelShafy, Mohamed M. Ahmed and Yasser A.S. Gamal
Research Department
Research Journal
Earthquakes and Structures
Research Member
Research Pages
55-70
Research Publisher
Techno-Press Publishers
Research Rank
1
Research Vol
20(1)
Research Website
http://www.techno-press.org/content/?page=article&journal=eas&volume=20&num=1&ordernum=5
Research Year
2021

Seismic pounding between adjacent buildings considering soil-structure interaction

Research Abstract
In urban cities, buildings were built in the neighborhood, these buildings influence each other through structure-soil-structure interaction (SSSI) and seismic pounding due to limited separation distance in-between. Generally, the effects of the interaction between soil and structure are disregarded during seismic design and analysis of superstructure. However, the system of soil-base adversely changes structural behavior and response demands. Thus, the vibration characteristics plus the seismic response of a building are not able to be independent of those in adjacent buildings. The interaction between structure, soil, and structure investigates the action of the attendance of adjacent buildings to the others by the interaction effect of the sub-soil under dynamic disturbances. The main purpose of this research is to analyze the effects of SSSI and seismic pounding on the behavior of adjacent buildings. The response of a single structure or two adjacent structures with shallow raft base lying on soft soil are studied. Three dimensions finite element models are developed to investigate the effects of pounding; gap distance; conditions of soil; stories number; a mass of adjacent building and ground excitation frequency on the seismic responses and vibration characteristics of the structures. The variation in the story displacement, story shear, and story moment responses demands are studied to evaluate the presence effect of the adjacent buildings. Numerical results acquired using conditions of soil models are compared with the condition of fixed support and adjacent building models to a single building model. The peak responses of story displacement, story moment, and story shear are studied.
Research Authors

Shehata E Abdel Raheem, Tarek M.A. Alazrak, Aly G.A. AbdelShafy, Mohamed M. Ahmed and Yasser A.S. Gamal
Research Department
Research Journal
Earthquakes and Structures
Research Pages
55-70
Research Publisher
Techno-Press Publishers
Research Rank
1
Research Vol
20(1)
Research Website
http://www.techno-press.org/content/?page=article&journal=eas&volume=20&num=1&ordernum=5
Research Year
2021

Impact of Layered Heterogeneity on Transient Saltwater Upconing in Coastal Aquifers

Research Abstract
NULL
Research Authors
Abdoulhalik, Antoifi, Abdelgawad, A.M. and Ahmed, A.A.
Research Department
Research Journal
Journal of Hydrology
Research Pages
pp. 124393
Research Publisher
Elsevier
Research Rank
1
Research Vol
Vol.581
Research Website
https://doi.org/10.1016/j.jhydrol.2019.124393
Research Year
2020

Transient Investigation of the Critical Abstraction Rates in Coastal Aquifers: Numerical and Experimental Study

Research Abstract
NULL
Research Authors
Abdelgawad, Abdelrahman M.; Abdoulhalik, Antoifi; Ahmed, Ashraf A.; Moutari, Salissou; Hamill, G.
Research Department
Research Journal
Water Resources Management
Research Pages
p 3563-3577
Research Publisher
NULL
Research Rank
1
Research Vol
v 32, n 11
Research Website
https://doi.org/10.1007/s11269-018-1988-3
Research Year
2018

An Adaptive Model-Based MPPT Technique with Drift-Avoidance for Grid-Connected PV Systems

Research Abstract
In this article, a modified control structure for a single-stage three phase grid-connected photovoltaic (PV) system is presented. In the proposed system, the maximum power point tracking (MPPT) function is developed using a new adaptive model-based technique, in which the maximum power point (MPP) voltage can be precisely located based on the characteristics of the PV source. By doing so, the drift problem associated with the traditional perturb and observe (P&O) technique can be easily solved. Moreover, the inverter control is accomplished using a predictive dead-beat function, which directly estimates the required reference voltages from the commanded reference currents. Then, the reference voltages are applied to a space vector pulse width modulator (SVPWM) for switching state generation. Furthermore, the proposed inverter control avoids the conventional and known cascaded loop structure of the voltage oriented control (VOC) method by elimination of the outer PI controller, and hence the overall control strategy is simplified. The proposed system is compared with different MPPT techniques, including the conventional P&O method and other techniques intended for drift avoidance. The evaluation of the suggested control methodology depends on various radiation profiles created in MATLAB. The proposed technique succeeds at capturing the maximum available power from the PV source with no drift in comparison with other methods.
Research Authors
Mostafa Ahmed, Mohamed Abdelrahem, Ibrahim Harbi, and Ralph Kennel
Research Department
Research Journal
Energies
Research Pages
25
Research Publisher
MDPI
Research Rank
1
Research Vol
Vol. 13
Research Website
https://www.mdpi.com/journal/energies
Research Year
2020

An Adaptive Model-Based MPPT Technique with Drift-Avoidance for Grid-Connected PV Systems

Research Abstract
In this article, a modified control structure for a single-stage three phase grid-connected photovoltaic (PV) system is presented. In the proposed system, the maximum power point tracking (MPPT) function is developed using a new adaptive model-based technique, in which the maximum power point (MPP) voltage can be precisely located based on the characteristics of the PV source. By doing so, the drift problem associated with the traditional perturb and observe (P&O) technique can be easily solved. Moreover, the inverter control is accomplished using a predictive dead-beat function, which directly estimates the required reference voltages from the commanded reference currents. Then, the reference voltages are applied to a space vector pulse width modulator (SVPWM) for switching state generation. Furthermore, the proposed inverter control avoids the conventional and known cascaded loop structure of the voltage oriented control (VOC) method by elimination of the outer PI controller, and hence the overall control strategy is simplified. The proposed system is compared with different MPPT techniques, including the conventional P&O method and other techniques intended for drift avoidance. The evaluation of the suggested control methodology depends on various radiation profiles created in MATLAB. The proposed technique succeeds at capturing the maximum available power from the PV source with no drift in comparison with other methods.
Research Authors
Mostafa Ahmed, Mohamed Abdelrahem, Ibrahim Harbi, and Ralph Kennel
Research Department
Research Journal
Energies
Research Member
Research Pages
25
Research Publisher
MDPI
Research Rank
1
Research Vol
Vol. 13
Research Website
https://www.mdpi.com/journal/energies
Research Year
2020
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