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Abbas Moustafa

Minia University, Civil Engineering Department, Faculty Member

Minia University, Civil Department, Faculty Member

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Dr. Abbas Moustafa go his dictoral degree in 2002 in earthquake engineering and structural reliability of nonlinear structures. He is currently professor of earthquake and structural engineering at Minia University.
Supervisors: CS Manohar, Izuru Takewaki, and Sankaran Mahadevan
Phone: +201000901313
Address: Badrashein, Giza 12018, Egypt

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Papers by Abbas Moustafa

Improving the earthquake resilience of buildings

Engineers are always interested in the worst-case scenario. One of the most important and challen... more Engineers are always interested in the worst-case scenario. One of the most important and challenging missions of structural engineers may be to narrow the range of unexpected incidents in building structural design. Redundancy, robustness and resilience play an important role in such circumstances. Improving the Earthquake Resilience of Buildings: The worst case approach discusses the importance of worst-scenario approach for improved earthquake resilience of buildings and nuclear reactor facilities.

Improving the Earthquake Resilience of Buildings: The worst case approach consists of two parts. The first part deals with the characterization and modeling of worst or critical ground motions on inelastic structures and the related worst-case scenario in the structural design of ordinary simple building structures. The second part of the book focuses on investigating the worst-case scenario for passively controlled and base-isolated buildings. This allows for detailed consideration of a range of topics including:

•A consideration of damage of building structures in the critical excitation method for improved building-earthquake resilience,
•A consideration of uncertainties of structural parameters in structural control and base-isolation for improved building-earthquake resilience, and
•New insights in structural design of super high-rise buildings under long-period ground motions.

Improving the Earthquake Resilience of Buildings: The worst case approach is a valuable resource for researchers and engineers interested in learning and applying the worst-case scenario approach in the seismic-resistant design for more resilient structures.

Natural Science-Special Issue on Earthquakes August 2012

This special issue of Natural Science, entitled Earthquakes, tackles a wide range of research sub... more This special issue of Natural Science, entitled Earthquakes, tackles a wide range of research subjects related to earthquakes, including their nature, measures, causes of occurrence, characteristics, attenuation modeling, soil wave amplification, methods and tools of recording, analysis and prediction, their effect on the built environment and methods of design, analysis, assessment, control and repair of engineering structures against seismic loads resulting from earthquakes. This special issue of Natural Science considers also other related subjects on explosions and volcanic phenomena and hyperbaric-Oxygen treatment due to crush injury resulting from earthquakes. The special issue contains fourteen research papers written by researchers and experts from several countries.

Earthquake-Resistant Structures - Design, Assessment and Rehabilitation

This book deals with earthquake-resistant structures, such as, buildings, bridges and liquid stor... more This book deals with earthquake-resistant structures, such as, buildings, bridges and liquid storage tanks. It contains twenty chapters covering several interesting research topics written by researchers and experts in the field of earthquake engineering. The book covers seismic-resistance design of masonry and reinforced concrete structures to be constructed as well as safety assessment, strengthening and rehabilitation of existing structures against earthquake loads. It also includes three chapters on electromagnetic sensing techniques for health assessment of structures, post earthquake assessment of steel buildings in fire environment and response of underground pipes to blast loads. The book provides the state-of-the-art on recent progress in earthquake-resistant structures. It should be useful to graduate students, researchers and practicing structural engineers.

Geotechnical earthquake engineering - soil liquefaction and seismic safety of dams and monuments

CRITICAL INPUT FOR INELASTIC STRUCTURES UNDER EVOLVING SEISMIC WAVES

Journal of Structural and …, Jan 1, 2011

Characterization and modeling of near-fault pulse-like strong ground motion via damage-based critical excitation method

Structural Engineering and …, Jan 1, 2010

Reliability analysis of uncertain structures using earthquake response spectra

This paper develops a probabilistic methodology for the seismic reliability analysis of structure... more This paper develops a probabilistic methodology for the seismic reliability analysis of structures with random properties. The earthquake loading is assumed to be described in terms of response spectra. The proposed methodology takes advantage of the response spectra and thus does not require explicit dynamic analysis of the actual structure. Uncertainties in the structural properties (e.g. member cross-sections, modulus of elasticity, member strengths, mass and damping) as well as in the seismic load (due to uncertainty associated with the earthquake load specification) are considered. The structural reliability is estimated by determining the failure probability or the reliability index associated with a performance function that defines safe and unsafe domains. The structural failure is estimated using a performance function that evaluates whether the maximum displacement has been exceeded. Numerical illustrations of reliability analysis of elastic and elastic-plastic single-story frame structures are presented first. The extension of the proposed method to elastic multi-degree-of-freedom uncertain structures is also studied and a solved example is provided.

Discussion of 'A new approach of selecting real input ground motions for seismic design: The most unfavourable real seismic design ground motions' by C‐H Zhai and …

Earthquake Engineering & Structural Dynamics, Jan 1, 2009

This discussion consists of two parts. The first part raises a few comments and questions on the ... more This discussion consists of two parts. The first part raises a few comments and questions on the method presented in the above paper. The second part proposes a measure for identifying resonant accelerograms in a set of earthquake records without the need for pre-processing of the records or inclusion of the structure dynamic analysis.

Use of probabilistic and deterministic measures to identify unfavorable earthquake records

Journal of Zhejiang University-Science A, Jan 1, 2009

This paper develops measures to identify resonant or unfavorable earthquake ground motions. Proba... more

Structural and sensor damage identification using the bond graph approach

Structural Control and …, Jan 1, 2010

This paper develops a new and efficient hybrid qualitative-quantitative system identification met... more This paper develops a new and efficient hybrid qualitative-quantitative system identification methodology for structures using the bond graph approach. Bond graphs provide a modeling framework that includes parametric models of both the physical system and the sensors. Structural damage is modeled as reductions in the parameter values of the structural components. Sensor faults are modeled as biases or drifts from true responses. The damage detection uses a statistical method to identify significant deviations of measurements from nominal healthy behavior of the structure. Damage isolation is carried out by comparing the predicted signatures of various damage scenarios with the observed behavior of the structure. The damage signatures are derived off-line before sensor data collection. Quantitative identification of the damage amount uses the least-squares method, analyzing only the sub-structure containing the damaged component. Numerical illustrations of damage identification of frame structures driven by time-varying loads are provided, highlighting the advantages with respect to sensor fault identification and computational efficiency.

Critical earthquake load inputs for multi-degree-of-freedom inelastic structures

Journal of Sound and Vibration, Jan 1, 2009

The problem of modeling earthquake ground motions as design inputs for multi-degree-of-freedom 10... more The problem of modeling earthquake ground motions as design inputs for multi-degree-of-freedom 10 inelastic structures is studied. The earthquake acceleration is expressed as a Fourier series 11 modulated by an envelope function. The coefficients of the series representation are calculated such 12 that the structure inelastic deformation is maximized subjected to predefined constraints. These 13 constraints are taken to reflect known characteristics of recorded earthquakes such as upper bounds 14 on the energy and peak values of the ground acceleration, velocity and displacement, and upper and 15 lower limits on the Fourier spectra of the ground acceleration. The material stress-strain behavior is 16 modeled using bilinear and elastic-plastic relations. The resulting nonlinear optimization problem is 17 solved by using the sequential quadratic optimization method. Issues related to various forms of 18 energy dissipated by the inelastic structure are explored. The study also examines the effect of 19

Discussion of Analytical Model of Ground Motion Pulses for the Design and Assessment of Seismic Protective Systems by W.-L. He and AK Agrawal

Journal of Structural Engineering, Jan 1, 2010

Optimal placement of viscoelastic dampers and supporting members under variable critical excitations

Earthquakes and …, Jan 1, 2009

Fault Diagnosis of Civil Engineering Structures using the Bond Graph Approach

… workshop on principles …, Jan 1, 2007

This paper develops a fault diagnosis methodology for civil engineering structures based on the b... more This paper develops a fault diagnosis methodology for civil engineering structures based on the bond graph approach. The bond graph theory provides a modeling framework that includes parametric models of the physical system and the sensors. Structural faults are modeled as abrupt or gradual damage in structural components. Sensor faults are modeled as biases or drifts from true measurements. Fault detection uses a statistical method to identify significant deviations of measurements from nominal behavior of the structure. Fault isolation is carried out by comparing predicted effects of hypothesized faults with observed behavior of the structure. Numerical illustrations of fault diagnosis of a frame structure driven by time-varying loads are provided.

Identification of resonant earthquake ground motion

Sadhana, Jan 1, 2010

Resonant ground motion has been observed in earthquake records measured at several parts of the w... more Resonant ground motion has been observed in earthquake records measured at several parts of the world. This class of ground motion is characterized by its energy being contained in a narrow frequency band. This paper develops measures to quantify the frequency content of the ground motion using the entropy principle and the dispersion index. These measures are based on the geometric properties of the power spectral density function of the ground acceleration. The application of these measures to quantify the frequency content of random earthquake models is demonstrated first. Subsequently, these measures are used to quantify the frequency content of the ground acceleration for near-field records measured at rock and soil sites, short-duration and long-duration earthquakes.

Deterministic and probabilistic representation of near-field pulse-like ground motion

Soil Dynamics and Earthquake Engineering, Jan 1, 2010

The response and damage assessment of engineering structures under near-field ground motions is c... more The response and damage assessment of engineering structures under near-field ground motions is currently of great interest. Near-field ground motion with directivity focusing or fling effects produces pulse-like ground motion that has characteristics different from those of ordinary records. This paper develops simple deterministic and probabilistic models for near-field pulse-like ground motions. These models belong to the class of engineering models that aim to replicate some of the gross features observed in near-field records. The ground velocity is expressed as a steady-state function or a stationary random process modulated by an envelope function. Both models account for the nonstationarity and the multiple pulses in the ground velocity. While the deterministic model is similar to some of the models developed earlier, the probabilistic model facilitates handling uncertainties in the ground motion and variability in the structure's properties. For instance, this model combined with structural reliability methods can be used for reliability assessment of structures under near-field random ground motion. The reduction of the structural response by adding supplemental dampers is also investigated.

Damage-based design earthquake loads for single-degree-of-freedom Inelastic structures

Journal of Structural Engineering, Jan 1, 2011

This paper develops a new framework for modeling design earthquake loads for inelastic structures... more This paper develops a new framework for modeling design earthquake loads for inelastic structures. Limited information on strong ground motions is assumed to be available only at the given site. The design earthquake acceleration is expressed as a Fourier series, with unknown amplitude and phase angle, modulated by an envelope function. The design ground acceleration is estimated by solving an inverse dynamic problem, using nonlinear programming techniques, so that the structure performance is minimized. At the same time, the design earthquake is constrained to the available information on past recorded ground motions. New measures of the structure performance based on energy concepts and damage indexes are introduced in this paper. Specifically, the structural performance is quantified in terms of Park and Ang damage indexes. Damage indexes imply that the structure is damaged by a combination of repeated stress reversals and high-stress excursions. Furthermore, the use of damage indexes provides a measure on the structure damage level, and making a decision on necessary repair possible. The material stress-strain relationship is modeled as either bilinear or elastic-plastic. The formulation is demonstrated by deriving the design earthquake loads for inelastic frame structures at a firm soil site. The damage spectra for the site are also established, to provide upper bounds of damage under possible future earthquakes.

Erratum: Modeling critical ground-motion sequences for inelastic structures (vol. 13, 665-679, 2010)

Advances in Structural Engineering, Jan 1, 2011

Damage-based design earthquake load inputs for inelastic structures

cuee.titech.ac.jp

This paper develops a new framework for modeling design earthquake loads for inelastic structures... more This paper develops a new framework for modeling design earthquake loads for inelastic structures. Limited information on strong ground motions is assumed to be available only at the given site. The design earthquake acceleration is expressed as a Fourier series, with unknown amplitude and phase angle, modulated by an envelope function. The design ground acceleration is estimated by solving an inverse dynamic problem, using nonlinear programming techniques, so that the structure performance is minimized. At the same time, the design earthquake is constrained to the available information on past recorded ground motions. New measures of the structure performance based on energy concepts and damage indexes are introduced in this paper. Specifically, the structural performance is quantified in terms of Park and Ang damage indexes. Damage indexes imply that the structure is damaged by a combination of repeated stress reversals and high-stress excursions. Furthermore, the use of damage indexes provides a measure on the structure damage level, and making a decision on necessary repair possible. The material stress-strain relationship is modeled as either bilinear or elastic-plastic. The formulation is demonstrated by deriving the design earthquake loads for inelastic frame structures at a firm soil site. The damage spectra for the site are also established, to provide upper bounds of damage under possible future earthquakes.

Sensor and structural health assessment of structures using bond graphs

cuee.titech.ac.jp

This research develops a new and efficient hybrid qualitativequantitative system identification ... more

Improving the earthquake resilience of buildings

Engineers are always interested in the worst-case scenario. One of the most important and challen... more Engineers are always interested in the worst-case scenario. One of the most important and challenging missions of structural engineers may be to narrow the range of unexpected incidents in building structural design. Redundancy, robustness and resilience play an important role in such circumstances. Improving the Earthquake Resilience of Buildings: The worst case approach discusses the importance of worst-scenario approach for improved earthquake resilience of buildings and nuclear reactor facilities.

Improving the Earthquake Resilience of Buildings: The worst case approach consists of two parts. The first part deals with the characterization and modeling of worst or critical ground motions on inelastic structures and the related worst-case scenario in the structural design of ordinary simple building structures. The second part of the book focuses on investigating the worst-case scenario for passively controlled and base-isolated buildings. This allows for detailed consideration of a range of topics including:

•A consideration of damage of building structures in the critical excitation method for improved building-earthquake resilience,
•A consideration of uncertainties of structural parameters in structural control and base-isolation for improved building-earthquake resilience, and
•New insights in structural design of super high-rise buildings under long-period ground motions.

Improving the Earthquake Resilience of Buildings: The worst case approach is a valuable resource for researchers and engineers interested in learning and applying the worst-case scenario approach in the seismic-resistant design for more resilient structures.

Natural Science-Special Issue on Earthquakes August 2012

This special issue of Natural Science, entitled Earthquakes, tackles a wide range of research sub... more This special issue of Natural Science, entitled Earthquakes, tackles a wide range of research subjects related to earthquakes, including their nature, measures, causes of occurrence, characteristics, attenuation modeling, soil wave amplification, methods and tools of recording, analysis and prediction, their effect on the built environment and methods of design, analysis, assessment, control and repair of engineering structures against seismic loads resulting from earthquakes. This special issue of Natural Science considers also other related subjects on explosions and volcanic phenomena and hyperbaric-Oxygen treatment due to crush injury resulting from earthquakes. The special issue contains fourteen research papers written by researchers and experts from several countries.

Earthquake-Resistant Structures - Design, Assessment and Rehabilitation

This book deals with earthquake-resistant structures, such as, buildings, bridges and liquid stor... more This book deals with earthquake-resistant structures, such as, buildings, bridges and liquid storage tanks. It contains twenty chapters covering several interesting research topics written by researchers and experts in the field of earthquake engineering. The book covers seismic-resistance design of masonry and reinforced concrete structures to be constructed as well as safety assessment, strengthening and rehabilitation of existing structures against earthquake loads. It also includes three chapters on electromagnetic sensing techniques for health assessment of structures, post earthquake assessment of steel buildings in fire environment and response of underground pipes to blast loads. The book provides the state-of-the-art on recent progress in earthquake-resistant structures. It should be useful to graduate students, researchers and practicing structural engineers.

Geotechnical earthquake engineering - soil liquefaction and seismic safety of dams and monuments

CRITICAL INPUT FOR INELASTIC STRUCTURES UNDER EVOLVING SEISMIC WAVES

Journal of Structural and …, Jan 1, 2011

Characterization and modeling of near-fault pulse-like strong ground motion via damage-based critical excitation method

Structural Engineering and …, Jan 1, 2010

Reliability analysis of uncertain structures using earthquake response spectra

This paper develops a probabilistic methodology for the seismic reliability analysis of structure... more This paper develops a probabilistic methodology for the seismic reliability analysis of structures with random properties. The earthquake loading is assumed to be described in terms of response spectra. The proposed methodology takes advantage of the response spectra and thus does not require explicit dynamic analysis of the actual structure. Uncertainties in the structural properties (e.g. member cross-sections, modulus of elasticity, member strengths, mass and damping) as well as in the seismic load (due to uncertainty associated with the earthquake load specification) are considered. The structural reliability is estimated by determining the failure probability or the reliability index associated with a performance function that defines safe and unsafe domains. The structural failure is estimated using a performance function that evaluates whether the maximum displacement has been exceeded. Numerical illustrations of reliability analysis of elastic and elastic-plastic single-story frame structures are presented first. The extension of the proposed method to elastic multi-degree-of-freedom uncertain structures is also studied and a solved example is provided.

Discussion of 'A new approach of selecting real input ground motions for seismic design: The most unfavourable real seismic design ground motions' by C‐H Zhai and …

Earthquake Engineering & Structural Dynamics, Jan 1, 2009

This discussion consists of two parts. The first part raises a few comments and questions on the ... more This discussion consists of two parts. The first part raises a few comments and questions on the method presented in the above paper. The second part proposes a measure for identifying resonant accelerograms in a set of earthquake records without the need for pre-processing of the records or inclusion of the structure dynamic analysis.

Use of probabilistic and deterministic measures to identify unfavorable earthquake records

Journal of Zhejiang University-Science A, Jan 1, 2009

This paper develops measures to identify resonant or unfavorable earthquake ground motions. Proba... more

Structural and sensor damage identification using the bond graph approach

Structural Control and …, Jan 1, 2010

This paper develops a new and efficient hybrid qualitative-quantitative system identification met... more This paper develops a new and efficient hybrid qualitative-quantitative system identification methodology for structures using the bond graph approach. Bond graphs provide a modeling framework that includes parametric models of both the physical system and the sensors. Structural damage is modeled as reductions in the parameter values of the structural components. Sensor faults are modeled as biases or drifts from true responses. The damage detection uses a statistical method to identify significant deviations of measurements from nominal healthy behavior of the structure. Damage isolation is carried out by comparing the predicted signatures of various damage scenarios with the observed behavior of the structure. The damage signatures are derived off-line before sensor data collection. Quantitative identification of the damage amount uses the least-squares method, analyzing only the sub-structure containing the damaged component. Numerical illustrations of damage identification of frame structures driven by time-varying loads are provided, highlighting the advantages with respect to sensor fault identification and computational efficiency.

Critical earthquake load inputs for multi-degree-of-freedom inelastic structures

Journal of Sound and Vibration, Jan 1, 2009

The problem of modeling earthquake ground motions as design inputs for multi-degree-of-freedom 10... more The problem of modeling earthquake ground motions as design inputs for multi-degree-of-freedom 10 inelastic structures is studied. The earthquake acceleration is expressed as a Fourier series 11 modulated by an envelope function. The coefficients of the series representation are calculated such 12 that the structure inelastic deformation is maximized subjected to predefined constraints. These 13 constraints are taken to reflect known characteristics of recorded earthquakes such as upper bounds 14 on the energy and peak values of the ground acceleration, velocity and displacement, and upper and 15 lower limits on the Fourier spectra of the ground acceleration. The material stress-strain behavior is 16 modeled using bilinear and elastic-plastic relations. The resulting nonlinear optimization problem is 17 solved by using the sequential quadratic optimization method. Issues related to various forms of 18 energy dissipated by the inelastic structure are explored. The study also examines the effect of 19

Discussion of Analytical Model of Ground Motion Pulses for the Design and Assessment of Seismic Protective Systems by W.-L. He and AK Agrawal

Journal of Structural Engineering, Jan 1, 2010

Optimal placement of viscoelastic dampers and supporting members under variable critical excitations

Earthquakes and …, Jan 1, 2009

Fault Diagnosis of Civil Engineering Structures using the Bond Graph Approach

… workshop on principles …, Jan 1, 2007

This paper develops a fault diagnosis methodology for civil engineering structures based on the b... more This paper develops a fault diagnosis methodology for civil engineering structures based on the bond graph approach. The bond graph theory provides a modeling framework that includes parametric models of the physical system and the sensors. Structural faults are modeled as abrupt or gradual damage in structural components. Sensor faults are modeled as biases or drifts from true measurements. Fault detection uses a statistical method to identify significant deviations of measurements from nominal behavior of the structure. Fault isolation is carried out by comparing predicted effects of hypothesized faults with observed behavior of the structure. Numerical illustrations of fault diagnosis of a frame structure driven by time-varying loads are provided.

Identification of resonant earthquake ground motion

Sadhana, Jan 1, 2010

Resonant ground motion has been observed in earthquake records measured at several parts of the w... more Resonant ground motion has been observed in earthquake records measured at several parts of the world. This class of ground motion is characterized by its energy being contained in a narrow frequency band. This paper develops measures to quantify the frequency content of the ground motion using the entropy principle and the dispersion index. These measures are based on the geometric properties of the power spectral density function of the ground acceleration. The application of these measures to quantify the frequency content of random earthquake models is demonstrated first. Subsequently, these measures are used to quantify the frequency content of the ground acceleration for near-field records measured at rock and soil sites, short-duration and long-duration earthquakes.

Deterministic and probabilistic representation of near-field pulse-like ground motion

Soil Dynamics and Earthquake Engineering, Jan 1, 2010

The response and damage assessment of engineering structures under near-field ground motions is c... more The response and damage assessment of engineering structures under near-field ground motions is currently of great interest. Near-field ground motion with directivity focusing or fling effects produces pulse-like ground motion that has characteristics different from those of ordinary records. This paper develops simple deterministic and probabilistic models for near-field pulse-like ground motions. These models belong to the class of engineering models that aim to replicate some of the gross features observed in near-field records. The ground velocity is expressed as a steady-state function or a stationary random process modulated by an envelope function. Both models account for the nonstationarity and the multiple pulses in the ground velocity. While the deterministic model is similar to some of the models developed earlier, the probabilistic model facilitates handling uncertainties in the ground motion and variability in the structure's properties. For instance, this model combined with structural reliability methods can be used for reliability assessment of structures under near-field random ground motion. The reduction of the structural response by adding supplemental dampers is also investigated.

Damage-based design earthquake loads for single-degree-of-freedom Inelastic structures

Journal of Structural Engineering, Jan 1, 2011

This paper develops a new framework for modeling design earthquake loads for inelastic structures... more This paper develops a new framework for modeling design earthquake loads for inelastic structures. Limited information on strong ground motions is assumed to be available only at the given site. The design earthquake acceleration is expressed as a Fourier series, with unknown amplitude and phase angle, modulated by an envelope function. The design ground acceleration is estimated by solving an inverse dynamic problem, using nonlinear programming techniques, so that the structure performance is minimized. At the same time, the design earthquake is constrained to the available information on past recorded ground motions. New measures of the structure performance based on energy concepts and damage indexes are introduced in this paper. Specifically, the structural performance is quantified in terms of Park and Ang damage indexes. Damage indexes imply that the structure is damaged by a combination of repeated stress reversals and high-stress excursions. Furthermore, the use of damage indexes provides a measure on the structure damage level, and making a decision on necessary repair possible. The material stress-strain relationship is modeled as either bilinear or elastic-plastic. The formulation is demonstrated by deriving the design earthquake loads for inelastic frame structures at a firm soil site. The damage spectra for the site are also established, to provide upper bounds of damage under possible future earthquakes.

Erratum: Modeling critical ground-motion sequences for inelastic structures (vol. 13, 665-679, 2010)

Advances in Structural Engineering, Jan 1, 2011

Damage-based design earthquake load inputs for inelastic structures

cuee.titech.ac.jp

This paper develops a new framework for modeling design earthquake loads for inelastic structures... more This paper develops a new framework for modeling design earthquake loads for inelastic structures. Limited information on strong ground motions is assumed to be available only at the given site. The design earthquake acceleration is expressed as a Fourier series, with unknown amplitude and phase angle, modulated by an envelope function. The design ground acceleration is estimated by solving an inverse dynamic problem, using nonlinear programming techniques, so that the structure performance is minimized. At the same time, the design earthquake is constrained to the available information on past recorded ground motions. New measures of the structure performance based on energy concepts and damage indexes are introduced in this paper. Specifically, the structural performance is quantified in terms of Park and Ang damage indexes. Damage indexes imply that the structure is damaged by a combination of repeated stress reversals and high-stress excursions. Furthermore, the use of damage indexes provides a measure on the structure damage level, and making a decision on necessary repair possible. The material stress-strain relationship is modeled as either bilinear or elastic-plastic. The formulation is demonstrated by deriving the design earthquake loads for inelastic frame structures at a firm soil site. The damage spectra for the site are also established, to provide upper bounds of damage under possible future earthquakes.

Sensor and structural health assessment of structures using bond graphs

cuee.titech.ac.jp

This research develops a new and efficient hybrid qualitativequantitative system identification ... more