Ismail Abdelkareem Moustafa, Mohammed
Total activity: 15
Research group
CODALAB - Control, Dynamics and Applications
Department
Department of Applied Mathematics III
E-mail
mohammed.ismailupc.edu
Contact details
UPC directory Open in new window

Graphic summary
  • Show / hide key
  • Information


Scientific and technological production
  •  

1 to 15 of 15 results
  • An isolation device for near-fault ground motions

     Ismail Abdelkareem Moustafa, Mohammed; Rodellar Benede, Jose Julian; Pozo Montero, Francesc
    Structural control & health monitoring
    Date of publication: 2014-03-01
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Seismic isolation is an appreciable control strategy that reduces the vibrations of structural and nonstructural systems induced by strong ground motions. However, under near-fault (NF) ground motion, the seismic isolation devices might perform poorly because of large isolator displacements caused by long-period large velocity and displacement pulses associated with such strong motion. The objective of this paper is to assess the effectiveness of a new seismic isolation device, referred to as roll-in-cage (RNC) isolator, in protecting against NF ground motions. The device is intended to achieve a balance in controlling isolator displacement demands and structural accelerations. The RNC isolator provides in a single unit all the necessary functions of rigid support, horizontal flexibility with enhanced stability, and energy dissipation characteristics. Moreover, it is distinguished from other isolation devices by two unique features: (i) it has a built-in energy-absorbing buffer to limit the design displacement under strong excitation, and (ii) it has a built-in linear recentering mechanism that prevents residual displacement after earthquakes. The seismic response of multistory buildings isolated by the RNC isolator is investigated under three recorded NF earthquakes and three synthetic ground motions. The results show that the RNC isolator is a convenient isolation system in protecting against NF earthquakes. Copyright (c) 2013 John Wiley & Sons, Ltd.

    Seismic isolation is an appreciable control strategy that reduces the vibrations of structural and nonstructural systems induced by strong ground motions. However, under near-fault (NF) ground motion, the seismic isolation devices might perform poorly because of large isolator displacements caused by long-period large velocity and displacement pulses associated with such strong motion. The objective of this paper is to assess the effectiveness of a new seismic isolation device, referred to as roll-in-cage (RNC) isolator, in protecting against NF ground motions. The device is intended to achieve a balance in controlling isolator displacement demands and structural accelerations. The RNC isolator provides in a single unit all the necessary functions of rigid support, horizontal flexibility with enhanced stability, and energy dissipation characteristics. Moreover, it is distinguished from other isolation devices by two unique features: (i) it has a built-in energy-absorbing buffer to limit the design displacement under strong excitation, and (ii) it has a built-in linear recentering mechanism that prevents residual displacement after earthquakes. The seismic response of multistory buildings isolated by the RNC isolator is investigated under three recorded NF earthquakes and three synthetic ground motions. The results show that the RNC isolator is a convenient isolation system in protecting against NF earthquakes.

  • Near-fault isolation of cable-stayed bridges using RNC isolator

     Ismail Abdelkareem Moustafa, Mohammed; Casas Rius, Joan Ramon; Rodellar Benede, Jose Julian
    Engineering structures
    Date of publication: 2013-11
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This paper investigates the near-fault (NF) seismic performance of a recent isolation system, referred to as Roll-N-Cage (RNC) isolator, considering the cable-stayed Bill Emerson Memorial Bridge in Missouri, USA. Under NF ground motion, the seismic isolation devices might perform poorly because of large isolator displacements caused by long-period large velocity and displacement pulses associated with such strong motion. The RNC isolator is designed to achieve a balance in controlling isolator displacement demands and structural accelerations. It provides in a single unit all the necessary functions of rigid support, horizontal flexibility with enhanced stability and energy dissipation characteristics. Moreover, it is distinguished from other isolation devices by two unique features: (1) it has a built-in energy absorbing buffer to limit the isolated deck displacement under severe seismic excitations to a preset value and (2) it has a built-in linear recentering mechanism that prevents residual displacement after earthquakes. The seismic response of the RNC-isolated cable-stayed bridge is investigated using nonlinear time history analysis under three recorded NF earthquakes and three synthetic ground accelerations that capture many of the kinematic characteristics of recorded NF ground motions. The results show that the RNC isolator is a convenient isolation system in protecting cable-stayed bridges against NF earthquakes.

    This paper investigates the near-fault (NF) seismic performance of a recent isolation system, referred to as Roll-N-Cage (RNC) isolator, considering the cable-stayed Bill Emerson Memorial Bridge in Missouri, USA. Under NF ground motion, the seismic isolation devices might perform poorly because of large isolator displacements caused by long-period large velocity and displacement pulses associated with such strong motion. The RNC isolator is designed to achieve a balance in controlling isolator displacement demands and structural accelerations. It provides in a single unit all the necessary functions of rigid support, horizontal flexibility with enhanced stability and energy dissipation characteristics. Moreover, it is distinguished from other isolation devices by two unique features: (1) it has a built-in energy absorbing buffer to limit the isolated deck displacement under severe seismic excitations to a preset value and (2) it has a built-in linear recentering mechanism that prevents residual displacement after earthquakes. The seismic response of the RNC-isolated cable-stayed bridge is investigated using nonlinear time history analysis under three recorded NF earthquakes and three synthetic ground accelerations that capture many of the kinematic characteristics of recorded NF ground motions. The results show that the RNC isolator is a convenient isolation system in protecting cable-stayed bridges against NF earthquakes.

  • Characterization, modeling and assessment of Roll-N-Cage isolator using the cable-stayed bridge benchmark

     Ismail Abdelkareem Moustafa, Mohammed; Rodellar Benede, Jose Julian; Carusone, Gennaro; Domaneschi, Marco; Martinelli, Luca
    Acta mechanica
    Date of publication: 2013-03
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This paper presents the results of an extensive series of simulation tests to identify the mechanical characteristics of an innovative isolation device known as the Roll-N-Cage (RNC) isolator. The seismic performance of an RNC passive control scheme is subsequently investigated on a model of the cable-stayed bridge benchmark. Starting from different configurations studied in the laboratory for a 1/10 reduced-scale prototype, the RNC isolator stiffness and damping properties are investigated in terms of cyclic tests with different parameters. Tests at the ultimate level state consisting of monotonic shear and axial loading have been also carried out as a part of the qualification process. The goal of this study is twofold: first, to examine the main integrated mechanisms of the RNC isolator through sophisticated 3D finite element simulation models using a multi-purpose finite element code...

    This paper presents the results of an extensive series of simulation tests to identify the mechanical characteristics of an innovative isolation device known as the Roll-N-Cage (RNC) isolator. The seismic performance of an RNC passive control scheme is subsequently investigated on a model of the cable-stayed bridge benchmark. Starting from different configurations studied in the laboratory for a 1/10 reduced-scale prototype, the RNC isolator stiffness and damping properties are investigated in terms of cyclic tests with different parameters. Tests at the ultimate level state consisting of monotonic shear and axial loading have been also carried out as a part of the qualification process. The goal of this study is twofold: first, to examine the main integrated mechanisms of the RNC isolator through sophisticated 3D finite element simulation models using a multi-purpose finite element code. The main result of this step is to attempt modeling the force–displacement relationship using the standard Bouc–Wen model of smooth hysteresis. The second aim of this study is the numerical assessment of the device efficiency through its implementation into a bridge model considering several ground motions as external excitations. Based on these extensive studies, it was found that the RNC isolator is promising as a reliable isotropic horizontal isolation device for bridge structures.

  • Hybrid RNC-isolation of structures under near-fault earthquakes

     Ismail Abdelkareem Moustafa, Mohammed; Pozo Montero, Francesc; Rodellar Benede, Jose Julian
    American Control Conference
    Presentation's date: 2012-06-29
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Seismic protection of low- to moderate-mass buildings using RNC isolator

     Ismail Abdelkareem Moustafa, Mohammed; Rodellar Benede, Jose Julian; Ikhouane, Fayçal
    Structural control & health monitoring
    Date of publication: 2012-02
    Journal article

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Discrete-time adaptive control of nonlinear base isolated structures

     Pozo Montero, Francesc; Rodellar Benede, Jose Julian; Ismail Abdelkareem Moustafa, Mohammed
    International journal of innovative computing information and control
    Date of publication: 2012-09
    Journal article

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Access to the full text
    Numerical characterization of RNC isolator experimental prototypes  Open access

     Ismail Abdelkareem Moustafa, Mohammed; Rodellar Benede, Jose Julian
    Experimental Vibration Analysis for Civil Engineering Structures
    Presentation's date: 2011-10-04
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    The results of an extensive series of numerical simulation tests to identify the mechanical characteristics of the recently proposed roll-n-cage (RNC) isolation bearing are presented. Several different configurations of a 1/10 reduced scale prototype are included in a deep parametric study. Cyclic horizontal displacement tests considering varying test parameters of shear displacement amplitude, axial load, and loading frequency were performed. The RNC isolator shear stiffness and damping properties were investigated in terms of the different test parameters. Ultimate level tests consisted of monotonic shear loading up to the maximum displacement limit of the RNC isolator at several different axial loads were performed. The RNC isolator is subjected to a tensile axial load to check its tension capacity. Attempts were done to analytically match the resulting force-displacement relationships using the versatile hysteretic Bouc-Wen model

  • Near-fault hybrid pounding mitigation of RNC-isolated structures

     Ismail Abdelkareem Moustafa, Mohammed; Pozo Montero, Francesc; Rodellar Benede, Jose Julian
    Seminar for Advanced Industrial Control Applications
    Presentation's date: 2011-11
    Presentation of work at congresses

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Protection of vibration-sensitive equipments in harsh environments

     Ismail Abdelkareem Moustafa, Mohammed; Rodellar Benede, Jose Julian
    European Conference on Earthquake Engineering
    Presentation's date: 2010
    Presentation of work at congresses

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Seismic isolation bearing for earthquake-resistant structures

     Ismail Abdelkareem Moustafa, Mohammed; Rodellar Benede, Jose Julian
    European Conference on Earthquake Engineering
    Presentation's date: 2010
    Presentation of work at congresses

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • An innovative isolation device for aseismic design

     Ismail Abdelkareem Moustafa, Mohammed; Rodellar Benede, Jose Julian; Ikhouane, Fayçal
    Engineering structures
    Date of publication: 2010-04
    Journal article

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Performance of structure-equipment systems with a novel roll-n-cage isolation bearing

     Ismail Abdelkareem Moustafa, Mohammed; Rodellar Benede, Jose Julian; Ikhouane, Fayçal
    Computers & structures
    Date of publication: 2009-12
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    In this the paper, the problem of mitigating the seismic response of sensitive equipments housed in building structures is addressed by isolating the structure with an innovative device referred to as roll-n-cage isolator. The device is described, characterized and represented by a hysteretic semi-physical mathematical model. A numerical performance assessment is performed by implementing the isolator in a building structure housing equipment in upper floors where accelerations are amplified and motions contain strong components at long periods. The numerical results show that the proposed isolator is efficient in substantially attenuating the structure–equipment response under a wide variety of actual earthquakes while exhibiting robust performance for a wide range of structures.

  • An innovative isolation device for aseismic design  Open access  awarded activity

     Ismail Abdelkareem Moustafa, Mohammed
    Defense's date: 2009-11-09
    Department of Geotechnical Engineering and Geo-Sciences, Universitat Politècnica de Catalunya
    Theses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    Basado en la idea de reducir la demanda sísmica en lugar de aumentar la capacidad resistente de las estructuras, el aislamiento sísmico es un método simple para mitigar o reducir los posibles daños producidos por los terremotos. La correcta aplicación de esta tecnología conduce a un mejor comportamiento de las estructuras, que sigue siendo esencialmente elástico durante los terremotos de gran magnitud. El núcleo de esta tecnología es el aislador. La mayoría de los aisladores sísmicos disponibles en la actualidad siguen teniendo limitaciones prácticas que impiden que funcionen según lo previsto e imponen restricciones a su uso efectivo y al nivel de protección proporcionado. En esta Tesis, se presenta un aislador sísmico avanzado llamado "roll-n-cage (RNC)". Se propone investigar su eficiencia a través de simulación numérica, en un intento de crear un sistema de aislamiento sísmico práctico, efectivo y económico, que tiene por objeto resolver los principales inconvenientes de los actuales sistemas de aislamiento sísmico, manteniendo sus principales ventajas. Este aislador incorpora aislamiento, disipación de energía, amortiguamiento y capacidad de fuerza recuperadora en una sola unidad. Además, ofrece una resistencia al viento significativa y una amplia gama de flexibilidad horizontal, por lo que es adecuado para proteger las estructuras de masa ligera, moderada y grande, así como para proteger equipos sensibles, hardware y / o antigüedades alojados en edificios. Por otra parte, las cuestiones relativas a la viabilidad, los costes de construcción y la disponibilidad de materiales, reducción o prevención de las respuestas de torsión y la resistencia a la elevación son abordados a fondo durante el diseño del aislador RNC. El aislador RNC propuesto es descrito en profundidad y sus principios de funcionamiento son presentados en detalle. La caracterización mecánica del dispositivo se ha llevado a cabo por medio de un código computacional sofisticado que simula la respuesta de los dispositivos como si estuvieran sujetos a una máquina de pruebas reales. A través de este esquema, se consigue analizar numéricamente el comportamiento del aislador RNC bajo el efecto simultáneo de cargas horizontales y verticales, como se da típicamente en situaciones prácticas. Además, se presenta una descripción matemática de las principales características asociadas a la rodadura de los aisladores RNC. Asimismo se obtiene un modelo matemático para describir en una forma razonable y manejable la relación fuerza desplazamiento exhibida por el aislador de RNC. Para evaluar la viabilidad del aislador RNC y para comprobar su capacidad para proteger los sistemas estructurales y no estructurales de los riesgos sísmicos, el dispositivo se implementa numéricamente en una variedad de estructuras con masas ligeras y grandes, además de en equipos sensibles alojados en los pisos superiores de dichas estructuras. Para extraer conclusiones de carácter relativamente general sobre el funcionamiento del aislador RNC, se estudia una amplia gama de terremotos y de características y propiedades de los aisladores y de las estructuras.Los resultados numéricos revelan que el aislador RNC propuesto puede reducir la respuesta sísmica frente a un amplio rango de excitaciones sísmicas, mientras que exhibe un rendimiento robusto para una gran variedad de estructuras. La Tesis incluye como apéndice un estudio en profundidad sobre el modelo de histéresis de Bouc-Wen. El estudio contiene una revisión de los primeros y últimos avances y aplicaciones de este modelo, que es ampliamente utilizado en la descripción de fenómenos de histéresis en las estructuras.

    Based on the concept of reducing seismic demand rather than increasing the earthquake resistant capacity of structures, seismic isolation is a surprisingly simple approach to mitigate or reduce earthquake damage potential. Proper application of this complex technology leads to better performing structures that will remain essentially elastic during large earthquakes. The core of this technology is the isolator. Most currently available seismic isolators still have practical limitations causing them not to function as anticipated and impose restrictions to their proper use and to the provided protection level. In this dissertation, an advanced rolling-based seismic isolator, named roll-n-cage (RNC) isolator, is proposed and investigated via numerical simulation as an attempt to create a practical, effective, and economic seismic isolation system that aims to fix the main drawbacks of the current seismic isolation systems while keeping their main advantages. This isolator incorporates isolation, energy dissipation, buffer and restoring force mechanisms in a single unit. Further, it offers a significant wind resistance and a great range of horizontal flexibility making it ideal to protect light, moderate and heavy mass structures as well as precious housed motion-sensitive equipment, hardware and/or antiquities. Moreover, issues related to practicality, construction costs and material availability, reducing or preventing torsional responses and uplift resistance are thoroughly addressed during the RNC bearing design.The proposed RNC isolator is deeply described and its principles of operation are extensively highlighted. The mechanical characterization of the device has been carried out by means of a sophisticated computer code in a machine-like environment, which accurately simulates the response of the device subjected to a real testing machine. Through this machine-like environment, a general scheme is followed to numerically examine the behavior of the RNC isolator under simultaneous horizontal and vertical loads as in typical practical situations. Further, a mathematical description of the main features associated to rolling of the RNC isolator is presented. An input-output mathematical model is obtained to describe in a reasonable and manageable form the force-displacement relationship exhibited by the RNC isolator.To assess the feasibility of the RNC isolator and to check its ability to protect structural and nonstructural systems from seismic hazards, it is numerically implemented to a variety of structures having light to heavy masses, in addition to motion-sensitive equipment housed in upper building floors. Further, and to draw relatively general conclusions about the performance of the RNC isolator, a wide range of ground motions, isolator characteristics and structural properties is considered. The numerical results reveal that the proposed RNC isolation bearing can mitigate the seismic responses under a variety of ground motion excitations while exhibiting robust performance for a wide range of structures. The dissertation is appended with an in-depth survey, that contains a review of the past, recent developments and implementations of the versatile Bouc-Wen model of smooth hysteresis, which is used extensively in modeling the hysteresis phenomenon in the dynamically excited nonlinear structures. This survey is the first of its kind about the model since its origination more than 30 years ago. The objective is to present some of the popular approaches that have utilized and/or developed that model to capture the hysteretic behavior offered by a variety of nonlinear systems. Then, the evaluation of their results and contributions (if any) is carried out to highlight their assets and limitations and to identify future directions in this research area.

  • Control, dinàmica i aplicacions (CODALAB)

     Mantecon Baena, Juan Antonio; Galvis Restrepo, Eduard; Ikhouane, Fayçal; Rubió Massegú, Josep; Vidal Segui, Yolanda; Rossell Garriga, Josep Maria; Palacios Quiñonero, Francisco; Pujol Vazquez, Gisela; Pozo Montero, Francesc; Mañosa Fernández, Víctor; Tibaduiza Burgos, Diego Alexander; Mujica Delgado, Luis Eduardo; Acho Zuppa, Leonardo; Gharibnezhad, Fahit; Ismail Abdelkareem Moustafa, Mohammed; Rodellar Benede, Jose Julian
    Participation in a competitive project

     Share

  • AÏLLAMENT SÍSMIC

     Barbat Barbat, Horia Alejandro; Ismail Abdelkareem Moustafa, Mohammed; Rodellar Benede, Jose Julian
    Participation in a competitive project

     Share