• Title/Summary/Keyword: Kelvin model

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ENERGY DECAY RATE FOR THE KELVIN-VOIGT TYPE WAVE EQUATION WITH BALAKRISHNAN-TAYLOR DAMPING AND ACOUSTIC BOUNDARY

  • Kang, Yong Han
    • East Asian mathematical journal
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    • v.32 no.3
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    • pp.355-364
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    • 2016
  • In this paper, we study exponential stabilization of the vibrations of the Kelvin-Voigt type wave equation with Balakrishnan-Taylor damping and acoustic boundary in a bounded domain in $R^n$. To stabilize the systems, we incorporate separately, the internal material damping in the model as like Kang [3]. Energy decay rate are obtained by the exponential stability of solutions by using multiplier technique.

ENERGY DECAY RATES FOR THE KELVIN-VOIGT TYPE WAVE EQUATION WITH ACOUSTIC BOUNDARY

  • Seo, Young-Il;Kang, Yong-Han
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.16 no.2
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    • pp.85-91
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    • 2012
  • In this paper, we study uniform exponential stabilization of the vibrations of the Kelvin-Voigt type wave equation with acoustic boundary in a bounded domain in $R^n$. To stabilize the systems, we incorporate separately, the internal material damping in the model as like Gannesh C. Gorain [1]. Energy decay rates are obtained by the exponential stability of solutions by using multiplier technique.

The Stability Evaluation of Concrete Face Rockfill Dam(CFRD) Using Settlement Measured at the Dam Crest and Kelvin Model (계측자료 및 Kelvin 모델에 의한 콘크리트 표면차수벽형 석괴댐(CFRD)의 안정성 평가)

  • Lee, Heeman;Lim, Heuidae;Cho, Gyechun;Song, Kiil
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.11
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    • pp.33-46
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    • 2013
  • Recently, the projects which are to increase the capacity of the flood control are being actively performed because of the abnormal climate changes throughout the country. In this study, the regression analysis was performed using both Kelvin model and the real settlement measured at the crest of the existing concrete face rockfill dam(CFRD) to estimate the long-term deformation behavior characteristics such as creep which occurs without additional load. In addition, the effects on changes in physical properties (E, G, K) of the dam construction materials by deformation characteristics of the dam were evaluated, and the reasonable stability analysis method of the dam was proposed to obtain the long-term stability considering the changes in physical properties induced by the long-term deformation behavior in case of heightening the existing dams.

Response of orthotropic Kelvin modeling for single-walled carbon nanotubes: Frequency analysis

  • Hussain, Muzamal;Naeem, Muhammad N.;Tounsi, Abdelouahed
    • Advances in nano research
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    • v.8 no.3
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    • pp.229-244
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    • 2020
  • In this paper, modified Kelvin's model has been used to analyze the orthotropic vibration frequencies of single walled carbon nanotubes with clamped-clamped and clamped-free boundary conditions. For this system the governing equation is developed with wave propagation approach. Armchair, zigzag and chiral structures are considered for the vibrational analysis to investigate the effect of different modes, in-plane rigidity and mass density per unit lateral area. Throughout the computations, on decreasing the length-to-diameter ratios, the frequencies of said structure increases. In addition, by increasing three different value of in-plane rigidity resulting frequencies also increase and frequencies decrease on increasing mass density per unit lateral area. The results generated using computer software MATLAB to furnish the evidence regarding applicability of present model and also verified by available published literature.

Continuous relaxation spectrum for the numerical analysis of concrete creep

  • Zi, Goang-Seup
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.466-471
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    • 2004
  • Efficient numerical finite element analysis of creeping concrete structures requires the use Kelvin or Maxwell chain model, which is most conveniently identified from a continuous retardation or relaxation spectrum, the spectrum in turn being determined from the given compliance or relaxation function. The method of doing that within the context of solidification theory for creep with aging was previously worked out by Bazant and Xi, but only for the case of a continuous retardation spectrum based on Kelvin chain. The present paper is motivated by the need to incorporate concrete creep into the recently published microplane model M4 for nonlinear triaxial behavior of concrete, including tensile fracturing and behavior under compression. In that context. the Maxwell chain is more effective than Kelvin chain. because of the kinematic constraint of the microplanes used in M4. Determination of the continuous relaxation spectrum for Maxwell chain. based on the solidification theory, is outlined and numerical examples are presented.

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Characteristics of the plume formed by the buoyant discharges from the river

  • Kim, Ki-Cheol;Kim, Sung-Bo
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.8
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    • pp.981-994
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    • 2014
  • Density currents formed by buoyancy discharges from rivers are numerically studied using non-dimensional two layer model including Coriolis acceleration, bottom stress, interfacial friction. Some typical numbers such as Froude number, densimetric Froude number and Kelvin number are obtained and some characteristic scales are defined as a result of non-dimensionalization of the governing equations. Besides the Coriolis effect, the configurations of bottom topography, bottom friction coefficient and interfacial friction are found to significantly affect the propagation of the warm water plume. Frontal position can fastly propagate in the case of large density difference between the two layers and small interfacial friction. Left side boundary current is easily formed under the small interfacial friction. With large Kelvin number, both right and left side boundary currents are formed. Wave-like disturbances and eddies are easily formed under the high Froude number.

Material model for load rate sensitivity

  • Kozar, Ivica;Ibrahimbegovic, Adnan;Rukavina, Tea
    • Coupled systems mechanics
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    • v.7 no.2
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    • pp.141-162
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    • 2018
  • This work presents a novel model for analysis of the loading rate influence onto structure response. The model is based on the principles of nonlinear system dynamics, i.e., consists of a system of nonlinear differential equations. In contrast to classical linearized models, this one comprises mass and loading as integral parts of the model. Application of the Kelvin and the Maxwell material models relates the novel formulation to the existing material formulations. All the analysis is performed on a proprietary computer program based on Wolfram Mathematica. This work can be considered as an extended proof of concept for the application of the nonlinear solid model in material response to dynamic loading.

Restitution Behaviors and Mechanical Characteristics of Strings (스트링의 반발거동과 역학적 특성)

  • 김태용;박진무
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.543-546
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    • 2000
  • Static and dynamic experiments were done to study on the restitution behaviors of strings. The elastic and viscoelastic model were compared. To apply a linear viscoelastic model (Kelvin model) to longitudinal behaviors of strings, static and dynamic tensile tests were done. Using their results, it should be intended to acquire damped stress (Stress related to velocity), and to calculate the viscoelastic coefficient. Fixing both ends, string was pushed by the loadcell attached to the tensile tester. The experimental results were in accordance with the calculated results using the Kelvin model acquired from the results of longitudinal tensile test. But the results of falling mass experiments, the behaviors of strings were near to elastic model. The clamping condition of strings in both sides has an effected on the value of COR. The smaller contact area, the grower the value of COR.

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Linear Modeling of Viscoelastic Dampers Considering Nonlinear Dynamic Behavior (점탄성 감쇠기의 비선형거동을 고려한 선형모델 해석)

  • Kim, Jin-Koo;Kwon, Young-Jip;Min, Kyung-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.1
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    • pp.171-177
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    • 2002
  • The viscoelastic dampers are considered to be one of the most efficient means of upgrading existing structures against seismic loads. Generally in the dynamic analysis of a structure with added viscoelastic dampers the internal forces of the dampers are represented by constants that are linearly proportional to displacement and velocity. The purpose of this study is to verify the validity of the linear Kelvin model by comparing the results from the linear analysis with those obtained from the more rigorous nonlinear model such as fractional derivative model. According to the results the structural responses of 1-DOF structure obtained using the linear model are very close to those obtained from nonlinear model. However for multi-D0F structure the difference between the results from both models is enlarged as a results of the assumptions associated with the linear modeling of the viscoelastic dampers.

Development of Contact Module in AutoDyn7 Program (AutoDyn7 프로그램의 접촉모듈 개발)

  • 임성현;손정현;김광석;유완석
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.6
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    • pp.152-159
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    • 2001
  • In multibody dynamic analysis including contact and impact, there are two major analysis methods, i.e., piecewise analysis and continuous analysis. Modeling of contact phenomena is mainly classified with a Kelvin-Voigt model or a model of Hertz contact model. In this paper, a contact module fur AutoDyn7 program was developed and implemented. Both the Kelvin-Voigt model and a model of Hertz contact law were developed. The process of this module is composed of contact distinction and the contact force calculation. Two examples were verified and compared to the commercial program DADS.

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