The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
Xinzhong Chen - One of the best experts on this subject based on the ideXlab platform.
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estimation of nonstationary crosswind response of tall buildings with nonlinear Aeroelastic Effect
Journal of Engineering Mechanics-asce, 2018Co-Authors: Changda Feng, Xinzhong ChenAbstract:AbstractThis study addresses analysis of the crosswind response of tall buildings under nonstationary wind excitations. The wind load under nonstationary wind excitation was quantified using the fo...
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extreme value distribution and peak factor of crosswind response of flexible structures with nonlinear Aeroelastic Effect
Journal of Structural Engineering-asce, 2014Co-Authors: Xinzhong ChenAbstract:AbstractThe crosswind response at the vicinity of vortex lock-in wind speed becomes an increasing concern in structural design of super tall buildings and other dynamically sensitive structures. Because of nonlinear Aeroelastic Effect of vortex shedding, the extreme value distribution and peak factor of crosswind response are distinctly different from traditional wind-induced stochastic buffeting response. This study establishes an Effective approach for predicting extreme value distribution and peak factor of crosswind response of flexible structures on the basis of an improved understanding of the underlying mechanism. It is pointed out that the improved extreme theory of Gaussian processes with consideration of narrow-band feature cannot interpret the extreme crosswind response. This study, at the first time, reveals that the unique characteristics of extreme value distribution of crosswind response is primarily attributed to its hardening non-Gaussian distribution. An extensive analysis of simulated c...
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estimation of extreme value distribution of crosswind response of wind excited flexible structures based on extrapolation of crossing rate
Engineering Structures, 2014Co-Authors: Xinzhong ChenAbstract:This paper presents an approach based on response crossing rate analysis for estimating extreme value distribution of crosswind response of wind-excited structures with significant nonlinear Aeroelastic Effect. The crossing rates at various thresholds are calculated from response time histories, and are then curve-fitted by a prescribed parametric model. The influence of narrow band characteristic of response is accounted by using envelope process with two-state description of crossings and a further consideration of mean clump size. The curve-fitting and extrapolation of crossing rate permit estimation of extreme value distribution using Poisson distribution of crossings. The Effectiveness and accuracy of the approach are examined using simulated crosswind responses covering a wide range of non-Gaussian characteristics, and also using full-scale vibration measurement data of a wind-excited traffic-signal-support structure. The results illustrated that the approach can produce robust estimations of extreme value distributions of hardening non-Gaussian crosswind responses. The narrow band characteristic of response process has very limited Effect on the extremes of hardening non-Gaussian responses. The approach presented is especially Effective in practice, where the number of available response time histories is often very limited, and a direct use of extreme samples fails to provide accurate estimation of extreme statistics.
Zhaolin Chen - One of the best experts on this subject based on the ideXlab platform.
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Aeroelastic Effect on modal interaction and dynamic behavior of acoustically excited metallic panels
Nonlinear Dynamics, 2017Co-Authors: Xiaochen Wang, Zhichun Yang, Wei Wang, Zhaolin ChenAbstract:This paper details the study of the Aeroelastic Effect on modal interaction and dynamic behavior of acoustically excited square metallic panels with fully clamped edges using finite element method. The first-order shear deformation plate theory and von Karman nonlinear strain–displacement relationships are employed to consider the structural geometric nonlinearity caused by large vibration deflections. Piston aerodynamic theory and Gaussian white noise are used to simulate the aerodynamic load and the acoustic load, respectively. Motion equations are derived by the principle of virtual work in the physical coordinates and then transformed into the truncated modal coordinates with reduced orders. Runge–Kutta method is employed to obtain the system response, and the modal interaction mechanism is quantitatively valued by the modal participation distribution. Results show that in the pre-/near-flutter regions, in addition to the dominant fundamental resonant mode, the first twin companion antisymmetric modes can be largely excited by the Aeroelastic coupling mechanism; thus, Aeroelastic modal participation distribution and the spectrum response can be altered, while the dynamic behavior still exhibits linear random vibrations. In the post-flutter region, the dominant flutter motion can be enriched by highly ordered odd order super-harmonic motion occurs due to 1:1 internal resonances. Correspondingly, the panel dynamic behavior changes from random vibration to highly ordered motions in the fashion of diffused limit-cycle oscillations (LCOs). However, this LCOs motion can be affected by the intensifying acoustic excitation through changing the Aeroelastic modal interaction mechanism. Accompanied with these changes, the panel can experience various stochastic bifurcations.
Xiaochen Wang - One of the best experts on this subject based on the ideXlab platform.
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Aeroelastic Effect on modal interaction and dynamic behavior of acoustically excited metallic panels
Nonlinear Dynamics, 2017Co-Authors: Xiaochen Wang, Zhichun Yang, Wei Wang, Zhaolin ChenAbstract:This paper details the study of the Aeroelastic Effect on modal interaction and dynamic behavior of acoustically excited square metallic panels with fully clamped edges using finite element method. The first-order shear deformation plate theory and von Karman nonlinear strain–displacement relationships are employed to consider the structural geometric nonlinearity caused by large vibration deflections. Piston aerodynamic theory and Gaussian white noise are used to simulate the aerodynamic load and the acoustic load, respectively. Motion equations are derived by the principle of virtual work in the physical coordinates and then transformed into the truncated modal coordinates with reduced orders. Runge–Kutta method is employed to obtain the system response, and the modal interaction mechanism is quantitatively valued by the modal participation distribution. Results show that in the pre-/near-flutter regions, in addition to the dominant fundamental resonant mode, the first twin companion antisymmetric modes can be largely excited by the Aeroelastic coupling mechanism; thus, Aeroelastic modal participation distribution and the spectrum response can be altered, while the dynamic behavior still exhibits linear random vibrations. In the post-flutter region, the dominant flutter motion can be enriched by highly ordered odd order super-harmonic motion occurs due to 1:1 internal resonances. Correspondingly, the panel dynamic behavior changes from random vibration to highly ordered motions in the fashion of diffused limit-cycle oscillations (LCOs). However, this LCOs motion can be affected by the intensifying acoustic excitation through changing the Aeroelastic modal interaction mechanism. Accompanied with these changes, the panel can experience various stochastic bifurcations.
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Aeroelastic Effect on aerothermoacoustic response of metallic panels in supersonic flow
Chinese Journal of Aeronautics, 2016Co-Authors: Xiaochen Wang, Zhichun Yang, Jian ZhouAbstract:Abstract A finite element formulation is presented for the analysis of the Aeroelastic Effect on the aerothermoacoustic response of metallic panels in supersonic flow. The first-order shear deformation theory (FSDT) and the von Karman nonlinear strain-displacement relationships are employed to consider the geometric nonlinearity induced by large deflections. The piston theory and the Gaussian white noise are used to simulate the mean flow aerodynamics and the turbulence from the boundary layer. The thermal loading is assumed to be steady and uniformly distributed, and the material properties are assumed to be temperature independent. The governing equations of motion are firstly formulated in structural node degrees of freedom by using the principle of virtual work, and then transformed and reduced to a set of coupled nonlinear Duffing oscillators in modal coordinates. The dynamic response of a panel is obtained by the Runge-Kutta integration method. The results indicate that the increasing Aeroelastic Effect can lead the panel vibration from a random motion to a highly ordered motion in the fashion of diffused limit cycle oscillations (LCOs), and remarkably alter the stochastic bifurcation and the spectrum of the aerothermoacoustic response. On the other hand there exists a counterbalance mechanism between the external random loading and the Aeroelastic Effect, which mainly functions through the nonlinear frequency-amplitude response. It is surmised that the Aeroelastic Effect must be considered in sonic fatigue analysis for panel structures in supersonic flow.
Zhichun Yang - One of the best experts on this subject based on the ideXlab platform.
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Aeroelastic Effect on modal interaction and dynamic behavior of acoustically excited metallic panels
Nonlinear Dynamics, 2017Co-Authors: Xiaochen Wang, Zhichun Yang, Wei Wang, Zhaolin ChenAbstract:This paper details the study of the Aeroelastic Effect on modal interaction and dynamic behavior of acoustically excited square metallic panels with fully clamped edges using finite element method. The first-order shear deformation plate theory and von Karman nonlinear strain–displacement relationships are employed to consider the structural geometric nonlinearity caused by large vibration deflections. Piston aerodynamic theory and Gaussian white noise are used to simulate the aerodynamic load and the acoustic load, respectively. Motion equations are derived by the principle of virtual work in the physical coordinates and then transformed into the truncated modal coordinates with reduced orders. Runge–Kutta method is employed to obtain the system response, and the modal interaction mechanism is quantitatively valued by the modal participation distribution. Results show that in the pre-/near-flutter regions, in addition to the dominant fundamental resonant mode, the first twin companion antisymmetric modes can be largely excited by the Aeroelastic coupling mechanism; thus, Aeroelastic modal participation distribution and the spectrum response can be altered, while the dynamic behavior still exhibits linear random vibrations. In the post-flutter region, the dominant flutter motion can be enriched by highly ordered odd order super-harmonic motion occurs due to 1:1 internal resonances. Correspondingly, the panel dynamic behavior changes from random vibration to highly ordered motions in the fashion of diffused limit-cycle oscillations (LCOs). However, this LCOs motion can be affected by the intensifying acoustic excitation through changing the Aeroelastic modal interaction mechanism. Accompanied with these changes, the panel can experience various stochastic bifurcations.
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Aeroelastic Effect on aerothermoacoustic response of metallic panels in supersonic flow
Chinese Journal of Aeronautics, 2016Co-Authors: Xiaochen Wang, Zhichun Yang, Jian ZhouAbstract:Abstract A finite element formulation is presented for the analysis of the Aeroelastic Effect on the aerothermoacoustic response of metallic panels in supersonic flow. The first-order shear deformation theory (FSDT) and the von Karman nonlinear strain-displacement relationships are employed to consider the geometric nonlinearity induced by large deflections. The piston theory and the Gaussian white noise are used to simulate the mean flow aerodynamics and the turbulence from the boundary layer. The thermal loading is assumed to be steady and uniformly distributed, and the material properties are assumed to be temperature independent. The governing equations of motion are firstly formulated in structural node degrees of freedom by using the principle of virtual work, and then transformed and reduced to a set of coupled nonlinear Duffing oscillators in modal coordinates. The dynamic response of a panel is obtained by the Runge-Kutta integration method. The results indicate that the increasing Aeroelastic Effect can lead the panel vibration from a random motion to a highly ordered motion in the fashion of diffused limit cycle oscillations (LCOs), and remarkably alter the stochastic bifurcation and the spectrum of the aerothermoacoustic response. On the other hand there exists a counterbalance mechanism between the external random loading and the Aeroelastic Effect, which mainly functions through the nonlinear frequency-amplitude response. It is surmised that the Aeroelastic Effect must be considered in sonic fatigue analysis for panel structures in supersonic flow.
Wu Yue - One of the best experts on this subject based on the ideXlab platform.
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wind tunnel tests on Aeroelastic Effect of wind induced vibration of tension structures
Engineering mechanics, 2008Co-Authors: Wu YueAbstract:Tension structures, such as cable net and textile structures, are characterized by their lightweight and flexibility, which make them rather sensitive to wind-induced dynamic excitation. In some cases, the interaction between structure and wind maybe play an important role to the wind induced response, which can not be accounted by conventional analytical methods. To solve this problem, a simplified Aeroelastic model, based on theoretical analysis and wind tunnel test, was put forward firstly. Some important parameters, such as aerodynamic damping and added mass, were introduced to describe the additional aerodynamic feedback terms involved in this Aeroelastic model. Then, a series of wind tunnel test of saddle-shaped membrane structures with rhombic plans were carried out to study the couple Effects of wind and tension structures. Random decrement technique was adopted to identify these parameters. The variation of aerodynamic damping and added mass with wind speed, exposure, structural stiffness and vibration mode shape were analyzed especially, and the mechanics of wind-structure interaction were discussed. It can be observed from these researches that the wind-induced vibration of membrane structures are characterized by broadband and forced vibrations; the Effect of aerodynamic damping is more significant than added mass, especially for lower vibration modes of structures, in which case the damping ratio can reach 15%; the magnitude of added mass is only about 1 time of structural mass; Aeroelastic instability of entire structure have not occurred in all experiments, but in some cases local Aeroelastic instability appeared in individual measurement points.
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study on wind induced vibration of membrane cable structures with the consideration of Aeroelastic Effect
Progress in Steel Building Structures, 2006Co-Authors: Wu YueAbstract:Tension structures,such as cable and membrane structures,are sensitive to wind-induced dynamic excitation; the analysis of wind-induced dynamic responses is an important procedure in the design of these structures.At present,there are few studies on wind-induced vibration analysis for tension structures,especially with the consideration of Aeroelastic interaction.At the first part,this paper discusses some characters and mainly research methods on wind-induced vibration analysis of tension structures.Then,the state-of- the-art studies on Aeroelastic Effect on large-span tent roofs is introduced.At the last part,some prospects on the further studies of this topic are put forward.