Anil Agrawal - Academia.edu (original) (raw)
Uploads
Papers by Anil Agrawal
The Journal of Infection in Developing Countries, 2010
Bookmarks Related papers MentionsView impact
IEEE Transactions on Nuclear Science, 2006
Bookmarks Related papers MentionsView impact
Structural Control & Health Monitoring, 2009
This paper presents the fully base-isolated highway bridge benchmark problem. The highway bridge ... more This paper presents the fully base-isolated highway bridge benchmark problem. The highway bridge benchmark problem consists of two phases: (1) Phase I—the bridge deck being base isolated only at the abutments and the center bent being integral with the pier (without isolation), and (2) Phase II—the bridge deck being fully base isolated at both the bent/pier and abutment locations. In both phases of the highway bridge benchmark, the objective is to augment the performance of the isolation system using supplemental control strategies. The problem definition (Part I) as well as a sample controller (Part II) for Phase I of the study has been presented in the companion papers. The focus of this paper is to present the fully base-isolated highway bridge and sample Lyapunov semiactive controller (Part III). As-built structural designs of the 91/5 overcrossing in Orange county in Southern California are used to develop the finite-element model for this benchmark based on Phase I. The nonlinear analysis tool and the controller interface have been developed in MATLAB. The bridge is isolated using nonlinear elastomeric bearings with a lead core. Magneto-rheological (MR) dampers are used to control the seismic response of the bridge. The MR dampers are installed at the isolation level at 10 locations over the abutments and bent/pier locations, each location consisting of an orthogonal pair of dampers to control the responses in both directions. The outputs allowed in the benchmark problem definition are used to design the controller and the velocity and displacement measurements if required are obtained by integrating accelerations using a filter, which simulates integration. Detailed comparisons of benchmark performance indices for the fully base-isolated bridge with sample semiactive controllers and passive strategies are performed in comparison with the uncontrolled case, for a set of strong near-field earthquakes. The sample Lyapunov semiactive controller is shown to reduce the isolator and mid-span displacements. The modeling and sample control designs demonstrated in this paper can be used to form the basis for studying a wider variety of active and semiactive control strategies—to be developed by the participants in the benchmark study—for fully base-isolated highway bridges. Copyright © 2009 John Wiley & Sons, Ltd.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Structural Control & Health Monitoring, 2009
This paper presents the problem definition of the benchmark structural control problem for the se... more This paper presents the problem definition of the benchmark structural control problem for the seismically excited highway bridge. The benchmark problem is based on the newly constructed 91/5 highway over-crossing in southern California. The goal of this benchmark effort is to develop a standardized model of a highway bridge using which competing control strategies, including devices, algorithms and sensors, can be evaluated comparatively. To achieve this goal, a 3D finite-element model is developed in MATLAB to represent the complex behavior of the full-scale highway over-crossing. The nonlinear behavior of center columns and isolation bearings is considered in formulating the bilinear force–deformation relationship. The effect of soil–structure interaction is considered by modeling the interaction by equivalent spring and dashpot. The ground motions are considered to be applied simultaneously in two directions. A MATLAB-based nonlinear structural analysis tool has been developed and made available for nonlinear dynamic analysis. Control devices are assumed to be installed between the deck and the end abutments of the bridge. Evaluation criteria and control constraints are specified for the design of controllers. Passive, semi-active and active devices and algorithms can be used to study the benchmark model. The participants in this benchmark study are required to define their control devices, sensors and control algorithms, evaluate and report the results of their proposed control strategies. Copyright © 2009 John Wiley & Sons, Ltd.
Bookmarks Related papers MentionsView impact
The Journal of Infection in Developing Countries, 2010
Bookmarks Related papers MentionsView impact
IEEE Transactions on Nuclear Science, 2006
Bookmarks Related papers MentionsView impact
Structural Control & Health Monitoring, 2009
This paper presents the fully base-isolated highway bridge benchmark problem. The highway bridge ... more This paper presents the fully base-isolated highway bridge benchmark problem. The highway bridge benchmark problem consists of two phases: (1) Phase I—the bridge deck being base isolated only at the abutments and the center bent being integral with the pier (without isolation), and (2) Phase II—the bridge deck being fully base isolated at both the bent/pier and abutment locations. In both phases of the highway bridge benchmark, the objective is to augment the performance of the isolation system using supplemental control strategies. The problem definition (Part I) as well as a sample controller (Part II) for Phase I of the study has been presented in the companion papers. The focus of this paper is to present the fully base-isolated highway bridge and sample Lyapunov semiactive controller (Part III). As-built structural designs of the 91/5 overcrossing in Orange county in Southern California are used to develop the finite-element model for this benchmark based on Phase I. The nonlinear analysis tool and the controller interface have been developed in MATLAB. The bridge is isolated using nonlinear elastomeric bearings with a lead core. Magneto-rheological (MR) dampers are used to control the seismic response of the bridge. The MR dampers are installed at the isolation level at 10 locations over the abutments and bent/pier locations, each location consisting of an orthogonal pair of dampers to control the responses in both directions. The outputs allowed in the benchmark problem definition are used to design the controller and the velocity and displacement measurements if required are obtained by integrating accelerations using a filter, which simulates integration. Detailed comparisons of benchmark performance indices for the fully base-isolated bridge with sample semiactive controllers and passive strategies are performed in comparison with the uncontrolled case, for a set of strong near-field earthquakes. The sample Lyapunov semiactive controller is shown to reduce the isolator and mid-span displacements. The modeling and sample control designs demonstrated in this paper can be used to form the basis for studying a wider variety of active and semiactive control strategies—to be developed by the participants in the benchmark study—for fully base-isolated highway bridges. Copyright © 2009 John Wiley & Sons, Ltd.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Structural Control & Health Monitoring, 2009
This paper presents the problem definition of the benchmark structural control problem for the se... more This paper presents the problem definition of the benchmark structural control problem for the seismically excited highway bridge. The benchmark problem is based on the newly constructed 91/5 highway over-crossing in southern California. The goal of this benchmark effort is to develop a standardized model of a highway bridge using which competing control strategies, including devices, algorithms and sensors, can be evaluated comparatively. To achieve this goal, a 3D finite-element model is developed in MATLAB to represent the complex behavior of the full-scale highway over-crossing. The nonlinear behavior of center columns and isolation bearings is considered in formulating the bilinear force–deformation relationship. The effect of soil–structure interaction is considered by modeling the interaction by equivalent spring and dashpot. The ground motions are considered to be applied simultaneously in two directions. A MATLAB-based nonlinear structural analysis tool has been developed and made available for nonlinear dynamic analysis. Control devices are assumed to be installed between the deck and the end abutments of the bridge. Evaluation criteria and control constraints are specified for the design of controllers. Passive, semi-active and active devices and algorithms can be used to study the benchmark model. The participants in this benchmark study are required to define their control devices, sensors and control algorithms, evaluate and report the results of their proposed control strategies. Copyright © 2009 John Wiley & Sons, Ltd.
Bookmarks Related papers MentionsView impact