• Title/Summary/Keyword: Dynamic response model

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Dynamic Response Characteristics of Embankment Model for Various Slope Angles (다양한 경사를 가지는 제방모형의 지반 증폭 특성)

  • Kim, Hoyeon;Jin, Yong;Lee, Yonghee;Kim, Hak-sung;Kim, Daehyeon
    • Journal of the Korean Geosynthetics Society
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    • v.19 no.2
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    • pp.35-46
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    • 2020
  • In this study, the dynamic response characteristics of the embankment model were analyzed using shaking table experiments. Laminar shear box was used to minimize the boundary effect of the model. The ratio of the vertical length to horizontal length of the slopes were 1:1, 1:1.5, and 1:2. The sensor array which is consist of 12 accelerometers was used to measure acceleration time-histories at each location of the slope model. The dynamic response characteristics of the models were analyzed for sine wave, sinesweep wave, and artificial earthquake wave in this study. The experimental results show that the dynamic response of the embankment model is increased with the slope angle. Furthermore, the experimental setup used in this study was verified with the comparative analysis between experimental results and 1-D analytical simulation on the flat ground model.

Along-wind simplified analysis of wind turbines through a coupled blade-tower model

  • Spagnoli, Andrea;Montanari, Lorenzo
    • Wind and Structures
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    • v.17 no.6
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    • pp.589-608
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    • 2013
  • A model is proposed to analyse the along-wind dynamic response of upwind turbines with horizontal axis under service wind conditions. The model takes into account the dynamic coupling effect between rotor blades and supporting tower. The wind speed field is decomposed into a mean component, accounting for the well-known wind shear effect, and a fluctuating component, treated through a spectral approach. Accordingly, the so-called rotationally sampled spectra are introduced for the blades to account for the effect of their rotating motion. Wind forces acting on the rotor blades are calculated according to the blade element momentum model. The tower shadow effect is also included in the present model. Two examples of a large and medium size wind turbines are modelled, and their dynamic response is analysed and compared with the results of a conventional static analysis.

Computer Simulation of Dynamic Response of Vehicles on Rough Ground (노면가진에 의한 차체의 동적거동에 관한 연구)

  • 조선휘;이건우;박종근;조병관;송성재;한규진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.3
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    • pp.419-425
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    • 1988
  • It would be very useful if the dynamic response of a vehicle over rough ground could be predicted at the early design stage. This became more promising with the recent progress in computer hardware and software technologies. In this study, a model of a passenger car has been developed for the analysis of its dynamic response. This model can be easily used for the other passenger cars with little modification. This passenger car was modeled to be composed of lumped masses, rigid bodies, and the suspension systems with nonlinear properties. Even though a commercial dynamic simulation program, ADAMS, was used in this study, the developed model is valid for any other simulation program. Finally, the validity of the developed model and the analysis result was verified by an experiment.

Dynamic response Analysis of Rockfill Dam (필댐의 지진응답 해석)

  • 이종욱
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.10a
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    • pp.113-120
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    • 1999
  • When we design the large rockfill dams the safety of dams against the quake must be considered. Generally pseudostatic analysis method has been used for slope stability and evaluation of safety but the case of dynamic response analysis of earthquake was not in general in Korea. Therefore we need to perform the dynamic response analysis of rockfill dams from these results we analyze the dynamic behavior of dam body such as response displacement and response acceleration. consequently we analyse the selected model of rockfill dam using the FLAC-2D (FDM) program.

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A Study on Dynamic Matrix Control to Boiler Steam Temperature (관류보일러 스팀 온도의 동역학 행렬 제어에 관한 연구)

  • Kim, Woo-Hun;Moon, Un-Chul
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.323-325
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    • 2009
  • In this paper, we present simulation results of Dynamic Matrix Control(DMC) to a boiler steam temperature. In order to control of steam temperature, we choose the input-output variables and generate the step response model by each input variable's step test. After that, the control structure executes on-line control with optimization using step response model. Proposed controller is applied to the APESS(Doosan company's boiler model simulator) and it is observed that the simulation results show satisfactory performance of proposed control.

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Model test method for dynamic responses of bridge towers subjected to waves

  • Chengxun Wei;Songze Yu;Jiang Du;Wenjing Wang
    • Structural Engineering and Mechanics
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    • v.86 no.6
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    • pp.705-714
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    • 2023
  • In order to establish a dynamic model test method of bridge pylons subjected to ocean waves, the similarity method of hydroelastic model test for bridge pylons were analyzed systematically, and a model design and production method was proposed. Using this method, a dynamic test model of a bridge pylon was made, and then a free vibration test on the model structure and a dynamic response test of the model structure under wave actions were conducted in a wave flume. The results of the free vibration test show that the primary natural frequencies of the structure by the model test are close to the design frequencies of the prototype structure, indicating that the dynamic characteristics of the bridge pylon are well simulated by the model structure. The results of the dynamic response test show that wave induced base shear forces and motion responses on the model structure are consistent with the numerical results of the prototype structure. The model test results confirm that the proposed model test design method is feasible and applicable. It has application and reference significances for model testing studies of such marine bridge structures.

Chaotic Response of a Nonlinear Vehicle Model and Elimination of the Chaos

  • Lai, Edmund;Park, Chan-Gook
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.106.6-106
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    • 2001
  • In this paper, a four-degree-of-freedom non-linear model is developed to study the dynamic response of vehicle that is caused by the disturbance from the road. The chaotic vibration of the model is investigated with numerical simulation. The model displays complicated dynamic responses including harmonic motions and chaos. It is found that changing of the damping coefficients of the system can eliminate the chaotic response.

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Dynamic Model to Predict Effect of Race Waviness on Vibrations Associated with Deep-Groove Ball Bearing

  • Hwang, Pyung;Nguyen, Van Trang
    • Tribology and Lubricants
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    • v.30 no.1
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    • pp.64-70
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    • 2014
  • This paper presents a numerical model for investigating the structural dynamics response of a rigid rotor supported on deep-groove ball bearings. The numerical model was used to investigate the influence of race waviness on the dynamic characteristics of a rotor ball bearing system, which is very important from a design viewpoint. The forth-order Runge-Kutta numerical integration technique was applied to determine the time displacement response, Poincare map, and frequency spectra. The analysis demonstrated that the model can be used as a tool for predicting the nonlinear dynamic behavior of a rotor ball bearing system under different operating conditions. The results of this study may help further understanding of the nonlinear dynamics of a rotor bearing system.

Dynamic response analysis of floating offshore wind turbine with different types of heave plates and mooring systems by using a fully nonlinear model

  • Waris, Muhammad Bilal;Ishihara, Takeshi
    • Coupled systems mechanics
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    • v.1 no.3
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    • pp.247-268
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    • 2012
  • A finite element model is developed for dynamic response prediction of floating offshore wind turbine systems considering coupling of wind turbine, floater and mooring system. The model employs Morison's equation with Srinivasan's model for hydrodynamic force and a non-hydrostatic model for restoring force. It is observed that for estimation of restoring force of a small floater, simple hydrostatic model underestimates the heave response after the resonance peak, while non-hydrostatic model shows good agreement with experiment. The developed model is used to discuss influence of heave plates and modeling of mooring system on floater response. Heave plates are found to influence heave response by shifting the resonance peak to longer period, while response after resonance is unaffected. The applicability of simplified linear modeling of mooring system is investigated using nonlinear model for Catenary and Tension Legged mooring. The linear model is found to provide good agreement with nonlinear model for Tension Leg mooring while it overestimates the surge response for Catenary mooring system. Floater response characteristics under different wave directions for the two types of mooring system are similar in all six modes but heave, pitch and roll amplitudes is negligible in tension leg due to high restraint. The reduced amplitude shall lead to reduction in wind turbine loads.

Seismic analysis of AL2O3 nanoparticles-reinforced concrete plates based on sinusoidal shear deformation theory

  • Amoli, Abolfazl;Kolahchi, Reza;Bidgoli, Mahmood Rabani
    • Earthquakes and Structures
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    • v.15 no.3
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    • pp.285-294
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    • 2018
  • In this study, nonlinear dynamic response of a concrete plate retrofit with Aluminium oxide ($Al_2O_3$) under seismic load and magnetic field is investigated. The plate is a composite reinforced by Aluminium oxide with characteristics of the equivalent composite being determined using Mori-Tanka model considering agglomeration effect. The plate is simulated with higher order shear deformation plate model. Employing nonlinear strains-displacements, stress-strain, the energy equations of column was obtained and using Hamilton's principal, the governing equations were derived. Differential quadrature method (DQM) in conjunction with Newark method is applied for obtaining the dynamic response of structure. The influences of magnetic field, volume percent of nanoparticles, geometrical parameters of column, agglomeration and boundary conditions on the dynamic response were investigated. Results showed that with increasing volume percent of nanoparticles, the dynamic deflection decreases.