The Experts below are selected from a list of 2433 Experts worldwide ranked by ideXlab platform
Ortega Enrique - One of the best experts on this subject based on the ideXlab platform.
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Efficient aeroelastic analysis of Inflatable Structures using enhanced potential flow aerodynamics
2019Co-Authors: Ortega Enrique, Flores Roberto, Cuartero Eric, Oñate EugenioAbstract:An efficient method for the aeroelastic analysis of wind effects on Inflatable Structures is presented. The solution scheme is staggered and uses an explicit finite-element structural solver and potential flow aerodynamics. In order to take into account the essential features of the flow around blunt-shaped Structures, a physics-based correction of the inviscid solution is proposed. The procedure involves automatic prediction of the detached flow areas (using Stratford’s criterion) and an empirical modification of the calculated pressure field intended to match the real viscous behavior. Several validation benchmarks and a realistic application example are presented. The results show the capability of the model to predict the wind loads on the structure with sufficient accuracy and low computational cost, making it possible to use aeroelastic analysis for routine calculation of Inflatable Structures
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Efficient aeroelastic analysis of Inflatable Structures using enhanced potential flow aerodynamics
'Elsevier BV', 2019Co-Authors: Ortega Enrique, Flores Le Roux, Roberto Maurice, Cuartero Zaragoza Eric, Oñate Ibáñez De Navarra, EugenioAbstract:An efficient method for the aeroelastic analysis of wind effects on Inflatable Structures is presented. The solution scheme is staggered and uses an explicit finite-element structural solver and potential flow aerodynamics. In order to take into account the essential features of the flow around blunt-shaped Structures, a physics-based correction of the inviscid solution is proposed. The procedure involves automatic prediction of the detached flow areas (using Stratford’s criterion) and an empirical modification of the calculated pressure field intended to match the real viscous behavior. Several validation benchmarks and a realistic application example are presented. The results show the capability of the model to predict the wind loads on the structure with sufficient accuracy and low computational cost, making it possible to use aeroelastic analysis for routine calculation of Inflatable Structures.Peer ReviewedPostprint (author's final draft
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Efficient aeroelastic analysis of wind loads on Inflatable hangars
International Centre for Numerical Methods in Engineering (CIMNE), 2019Co-Authors: Flores Le Roux, Roberto Maurice, Ortega EnriqueAbstract:Wind loads play a crucial role in Inflatable Structures. Unfortunately, design loads from safety regulations grossly overestimate the real aerodynamic forces. Thus, a more accurate estimation of wind loads is desirable. Conventional CFD approaches (e.g. LES) struggle with the complexities of the flow field (intricate geometry and massive flow separation) and require a very high computational effort. We present a cost-efficient tool for the aeroelastic analysis of Inflatable hangars. It uses a staggered solution scheme with an explicit finite-element structural solver and potential flow aerodynamics. To account for large areas of separated flow typical of blunt shapes, a semi-empirical correction is applied to the inviscid solution. The streamlines of the potential solution are computed and, for each one, the separation point is predicted with Stratford’s criterion. Finally, an empirical correction is applied to the inviscid pressure field. We present validation benchmarks as well as a real life application example. Over the majority of the flow field, the pressure field agrees well with high-fidelity computations, yielding similar global loads for structural sizing. This is achieved with a small fraction of the computational effort required by conventional CFD approaches.Postprint (published version
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Efficient aeroelastic analysis of wind loads on Inflatable hangars
International Centre for Numerical Methods in Engineering (CIMNE), 2019Co-Authors: Flores Le Roux, Roberto Maurice, Ortega EnriqueAbstract:Wind loads play a crucial role in Inflatable Structures. Unfortunately, design loads from safety regulations grossly overestimate the real aerodynamic forces. Thus, a more accurate estimation of wind loads is desirable. Conventional CFD approaches (e.g. LES) struggle with the complexities of the flow field (intricate geometry and massive flow separation) and require a very high computational effort. We present a cost-efficient tool for the aeroelastic analysis of Inflatable hangars. It uses a staggered solution scheme with an explicit finite-element structural solver and potential flow aerodynamics. To account for large areas of separated flow typical of blunt shapes, a semi-empirical correction is applied to the inviscid solution. The streamlines of the potential solution are computed and, for each one, the separation point is predicted with Stratford’s criterion. Finally, an empirical correction is applied to the inviscid pressure field. We present validation benchmarks as well as a real life application example. Over the majority of the flow field, the pressure field agrees well with high-fidelity computations, yielding similar global loads for structural sizing. This is achieved with a small fraction of the computational effort required by conventional CFD approaches
Daniel J. Inman - One of the best experts on this subject based on the ideXlab platform.
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vibration analysis and control of an Inflatable structure using smart materials
2004Co-Authors: Daniel J. InmanAbstract:Abstract : Lightweight Inflatable Structures, or Gossamer spacecraft, are very attractive in aerospace applications for several reasons. These Structures pose difficult problems, however, in modeling and in control due to their special geometry and material properties. Initially, the proposed work was to examine the nonlinear structural dynamics of an inflated torus with a membrane attached to it for the purpose of providing suitable models for the application of nonlinear control. This work/award commenced in April 2003. In March 2004, after a site visit by the AFOSR Program Manager, the focus of this effort was changed to correspond more closely with AFRL interests. In particular, after conversations with AFRL/DEBS and AFRL/VSSV, both of Kirtland AFB, the focus of the proposed effort was changed to examine the structural dynamics of a pressurized membrane with the goal of providing a sound modeling and theoretical understanding of the coupled structure, fluid, optical and control hardware of AFRL/DEBS's proposed system. The following is a brief report of our activities over 11 months of funding. The section numbers correspond to the categories requested on the AFOSR website for progress reports.
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Dynamic testing of Inflatable Structures using smart materials
Smart Materials and Structures, 2002Co-Authors: Gyu Hae Park, E. Ruggiero, Daniel J. InmanAbstract:In this paper we present experimental investigations of the vibration testing of an inflated, thin-film torus using smart materials. Lightweight, Inflatable Structures are very attractive in satellite applications. However, the lightweight, flexible and highly damped nature of inflated Structures poses difficulties in ground vibration testing. In this study, we show that polyvinylidene fluoride (PVDF) patches and recently developed macro-fiber composite actuators may be used as sensors and actuators in identifying modal parameters. Both smart materials can be integrated unobtrusively into the skin of a torus or space device forming an attractive testing arrangement. The addition of actuators and PVDF sensors to the torus does not significantly interfere with the suspension modes of a free-free boundary condition, and can be considered an integral part of the inflated structure. The results indicate the potential of using smart materials to measure and control the dynamic response of inflated Structures.
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Integration of Smart Materials into Dynamics and Control of Inflatable Space Structures
Journal of Intelligent Material Systems and Structures, 2001Co-Authors: Gyu Hae Park, Myung Hyun Kim, Daniel J. InmanAbstract:An experimental investigation of vibration testing and control of an inflated thin-film torus is presented. Lightweight Inflatable Structures are a viable alternative in aerospace structure design. These Structures, however, pose special problems in testing and in controlling vibrations due to their extremely lightweight, flexible, and high-damping properties. In this study, we show that smart materials, which can be fully integrated into an Inflatable space system, could be used as sensors/actuators in order to find modal parameters and to reduce vibrations. The results indicate the potential smart materials for use in the dynamics and control of inflated Structures.
Flores Le Roux, Roberto Maurice - One of the best experts on this subject based on the ideXlab platform.
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Efficient aeroelastic analysis of Inflatable Structures using enhanced potential flow aerodynamics
'Elsevier BV', 2019Co-Authors: Ortega Enrique, Flores Le Roux, Roberto Maurice, Cuartero Zaragoza Eric, Oñate Ibáñez De Navarra, EugenioAbstract:An efficient method for the aeroelastic analysis of wind effects on Inflatable Structures is presented. The solution scheme is staggered and uses an explicit finite-element structural solver and potential flow aerodynamics. In order to take into account the essential features of the flow around blunt-shaped Structures, a physics-based correction of the inviscid solution is proposed. The procedure involves automatic prediction of the detached flow areas (using Stratford’s criterion) and an empirical modification of the calculated pressure field intended to match the real viscous behavior. Several validation benchmarks and a realistic application example are presented. The results show the capability of the model to predict the wind loads on the structure with sufficient accuracy and low computational cost, making it possible to use aeroelastic analysis for routine calculation of Inflatable Structures.Peer ReviewedPostprint (author's final draft
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Efficient aeroelastic analysis of wind loads on Inflatable hangars
International Centre for Numerical Methods in Engineering (CIMNE), 2019Co-Authors: Flores Le Roux, Roberto Maurice, Ortega EnriqueAbstract:Wind loads play a crucial role in Inflatable Structures. Unfortunately, design loads from safety regulations grossly overestimate the real aerodynamic forces. Thus, a more accurate estimation of wind loads is desirable. Conventional CFD approaches (e.g. LES) struggle with the complexities of the flow field (intricate geometry and massive flow separation) and require a very high computational effort. We present a cost-efficient tool for the aeroelastic analysis of Inflatable hangars. It uses a staggered solution scheme with an explicit finite-element structural solver and potential flow aerodynamics. To account for large areas of separated flow typical of blunt shapes, a semi-empirical correction is applied to the inviscid solution. The streamlines of the potential solution are computed and, for each one, the separation point is predicted with Stratford’s criterion. Finally, an empirical correction is applied to the inviscid pressure field. We present validation benchmarks as well as a real life application example. Over the majority of the flow field, the pressure field agrees well with high-fidelity computations, yielding similar global loads for structural sizing. This is achieved with a small fraction of the computational effort required by conventional CFD approaches.Postprint (published version
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Efficient aeroelastic analysis of wind loads on Inflatable hangars
International Centre for Numerical Methods in Engineering (CIMNE), 2019Co-Authors: Flores Le Roux, Roberto Maurice, Ortega EnriqueAbstract:Wind loads play a crucial role in Inflatable Structures. Unfortunately, design loads from safety regulations grossly overestimate the real aerodynamic forces. Thus, a more accurate estimation of wind loads is desirable. Conventional CFD approaches (e.g. LES) struggle with the complexities of the flow field (intricate geometry and massive flow separation) and require a very high computational effort. We present a cost-efficient tool for the aeroelastic analysis of Inflatable hangars. It uses a staggered solution scheme with an explicit finite-element structural solver and potential flow aerodynamics. To account for large areas of separated flow typical of blunt shapes, a semi-empirical correction is applied to the inviscid solution. The streamlines of the potential solution are computed and, for each one, the separation point is predicted with Stratford’s criterion. Finally, an empirical correction is applied to the inviscid pressure field. We present validation benchmarks as well as a real life application example. Over the majority of the flow field, the pressure field agrees well with high-fidelity computations, yielding similar global loads for structural sizing. This is achieved with a small fraction of the computational effort required by conventional CFD approaches
Gyu Hae Park - One of the best experts on this subject based on the ideXlab platform.
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Dynamic testing of Inflatable Structures using smart materials
Smart Materials and Structures, 2002Co-Authors: Gyu Hae Park, E. Ruggiero, Daniel J. InmanAbstract:In this paper we present experimental investigations of the vibration testing of an inflated, thin-film torus using smart materials. Lightweight, Inflatable Structures are very attractive in satellite applications. However, the lightweight, flexible and highly damped nature of inflated Structures poses difficulties in ground vibration testing. In this study, we show that polyvinylidene fluoride (PVDF) patches and recently developed macro-fiber composite actuators may be used as sensors and actuators in identifying modal parameters. Both smart materials can be integrated unobtrusively into the skin of a torus or space device forming an attractive testing arrangement. The addition of actuators and PVDF sensors to the torus does not significantly interfere with the suspension modes of a free-free boundary condition, and can be considered an integral part of the inflated structure. The results indicate the potential of using smart materials to measure and control the dynamic response of inflated Structures.
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Integration of Smart Materials into Dynamics and Control of Inflatable Space Structures
Journal of Intelligent Material Systems and Structures, 2001Co-Authors: Gyu Hae Park, Myung Hyun Kim, Daniel J. InmanAbstract:An experimental investigation of vibration testing and control of an inflated thin-film torus is presented. Lightweight Inflatable Structures are a viable alternative in aerospace structure design. These Structures, however, pose special problems in testing and in controlling vibrations due to their extremely lightweight, flexible, and high-damping properties. In this study, we show that smart materials, which can be fully integrated into an Inflatable space system, could be used as sensors/actuators in order to find modal parameters and to reduce vibrations. The results indicate the potential smart materials for use in the dynamics and control of inflated Structures.
Cezary Graczykowski - One of the best experts on this subject based on the ideXlab platform.
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mathematical models and numerical methods for the simulation of adaptive Inflatable Structures for impact absorption
Computers & Structures, 2016Co-Authors: Cezary GraczykowskiAbstract:The paper describes various approaches for the mathematical modelling of Adaptive Inflatable Structures (AIS) along with the corresponding numerical methods. The introductory part presents a general idea of adaptive impact absorption (AIA) and the concept of Inflatable Structures equipped with controllable valves serving for internal pressure control. Application of AIS for adaptive absorption of the impact loading is briefly explained. The paper focuses on diverse methods of modelling of Inflatable Structures, which are based on interaction between solid walls and fluid enclosed inside. Modelling of the solid walls is based on rigid body dynamics or initial-boundary value problem of solid mechanics. In turn, modelling of the fluid utilizes either classical equilibrium thermodynamics or Navier-Stokes equations. Consequently, four possible combinations of the above approaches are distinguished, precisely analyzed and applied for the modelling of different types of Inflatable Structures. Each model takes into account controllable valves, which requires introducing additional coupling between parameters defining the valves and selected results of the analysis. Corresponding numerical methods include classical methods of solving ordinary differential equations, finite volume method (FVM) applied for problems with mobile boundaries, finite element method (FEM) applied for problems involving additional ODEs and, finally, FEM coupled with FVM. Proposed numerical methods and software tools are utilized for the simulation of adaptive pneumatic cylinders, adaptive pneumatic fenders and membrane valves.
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protecting offshore wind turbines against ship impacts by means of adaptive Inflatable Structures
Shock and Vibration, 2009Co-Authors: Cezary Graczykowski, Jan HolnickiszulcAbstract:Collisions with small service ships are serious danger for offshore wind turbines. Installing torus-shaped adaptive Inflatable structure that surrounds a wind turbine tower at water level is one method of effective protection. Proposed pneumatic structure contains several separate air chambers equipped with devices for fast inflation and pressure release. The system can be adapted to various impact scenarios by adjusting the level of initial pressure in each chamber and by controlling the release of compressed air during collision. The paper presents finite element simulation of ship collision with wind turbine tower protected by pneumatic structure, conducted using ABAQUS software. Introduced methods of pressure adjustment are aimed at mitigating tower and ship response. The performed feasibility study proves that Inflatable structure can effectively protect the wind turbine tower and the ship against serious damage.