• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4239-4249
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• 2011

In the country with frequent earthquakes like Japan, resistance to earthquake is assessed on the basis that Dam body's Face slab is destroyed by concentrated stress. In our country this kind of modeling and analysis is not yet definitely established. This paper performed pseudo static analysis and dynamic analysis for CFRD and evaluated reliability with the results of Shaking Table Test. The Seismic coefficient method, modified seismic coefficient method, Newmark method of Pseudo-static analysis and frequency domain response analysis, time domain history analysis of dinamic analysis were used. The analysis results were differ between analysis method, but the trends of acceleration and displacement were good agreement with the results of shaking table test.

• Journal of Korean Society of Disaster and Security
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• v.6 no.3
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• pp.1-8
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• 2013

Based on random vibration theory, a procedure for calculating the dynamic response of the tall building to time-dependent random excitation is developed. In this paper, the fluctuating along- wind load is assumed as time-dependent random process described by the time-independent random process with deterministic function during a short duration of time. By deterministic function A(t)=1-exp($-{\beta}t$), the absolute value square of oscillatory function is represented from author's studies. The time-dependent random response spectral density is represented by using the absolute value square of oscillatory function and equivalent wind load spectrum of Solari. Especially, dynamic mean square response of the tall building subjected to fluctuating wind loads was derived as analysis function by the Cauchy's Integral Formula and Residue Theorem. As analysis examples, there were compared the numerical integral analytic results with the analysis fun. results by dynamic properties of the tall uilding.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.3
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• pp.231-242
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• 2009

In the design of a sky-bridge, repetitive boundary nonlinear time history analyses are required to accurately predict dynamic behaviors of the connected buildings because the connection systems of a sky-bridge usually have high nonlinearity. If a conventional finite element model for entire high-rise buildings is used for repetitive boundary nonlinear time history analyses, computational efforts could be significant. In this study, an equivalent cantilever model considering the belt-wall effect has been proposed for an efficient dynamic analysis and a performance evaluation of vibration control of high-rise buildings connected by a sky-bridge. To verify the accuracy and efficiency of the proposed equivalent model, boundary nonlinear time history analyses of 49- and 42-story example buildings connected by a sky-bridge have been performed for wind excitation. Based on the analytical results, it has been verified that the proposed equivalent model can provide accurate dynamic responses of building structures connected by a sky-bridge with significantly reduced computational efforts.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.331-337
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• 2018

This paper presents dynamic algorithm of the MLS(moving least squares) difference method using first order differential Approximation. The governing equations are only discretized by the first order MLS derivative approximation. The system equation consists of an assembly of the approximate function, so the shape of system equation is similar to FEM(finite element method). The CDM(central difference method) is used for time integration of dynamic equilibrium equation. The natural frequency analyses of the MLS difference method and FEM are performed, and two analysis results are compared. Also, the accuracy of the proposed numerical method is verified by displaying the dynamic analysis results together with the results by the existing second order differential approximation. In the process of assembling the first order MLS derivative approximation, the oscillation error was suppressed and the stress distribution was interpreted as relatively uniform.

• Journal of Korean Society of Steel Construction
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• v.14 no.2
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• pp.329-337
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• 2002

The skid proof pavement is used for safety driving on curved bridges and high level roads. This study analyzed the effect of skid proof pavement on the bridge using actual spot test and computer analysis. In the actual spot test, the natural frequency and dynamic deflection of steel box girder bridges were measured before and after skid proof pavement. Likewise, in the computer analysis, the dynamic response of the finite element model was evaluated. The model was based on real steel box girder bridge according to the skid proof pavement. The analyzed results provide basic data on the effect of skid proof pavement on road structure.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1387-1395
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• 2013

When the center of mass of a railway wheel is not aligned with the geometrical center of the wheel axis, wheel unbalance occurs. If a railway vehicle runs without removing the wheel unbalance, vibrations will be produced. This will also cause wear and damage of the axle bearing. In this study, dynamic analysis of a railway vehicle with wheel unbalance was conducted to examine the reduction in critical speed and the resonance of the car-body and the effect on the magnitude of wheel unbalance was examined. In addition, the calculation of the car-body vibration owing to static and dynamic unbalance in the railway wheel shows that two-plane balancing is necessary.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.3
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• pp.121-128
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• 2021

Piloti-type buildings in Korea are usually composed of lower frames and upper shear wall structures. Piloti-type buildings have been seriously damaged during earthquakes because of the construction of soft and weak stories. Piloti-type buildings with edge cores are two-way unsymmetric planes. This paper analyzed and obtained the dynamic response for structures modeled using a multistory two-way asymmetric system. The numerical results, obtained using the Newmark-β method, show the time-history responses and trends of maximum displacements and shear forces. The purpose of this study is to evaluate the effect of reinforcement on dynamic response when a shear wall or brace is reinforced in the corner opposite the piloti.

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.67-76
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• 2016

The asphalt-concrete trackbed system has many advantages in terms of maintenance and economics. However, methods to investigate practical use corresponding to the development of the trackbed system must be developed. The primary objective of this study was to evaluate the dynamic performance of the asphalt system in accordance with both the elastic and viscoelastic material characteristics and design thickness of the asphalt trackbed. More specifically, in order to reduce the uncertainty error of the Finite Element(FE) model, a three-dimensional full scale FE model was developed and then the infinite foundation model was considered. Finally, to compare the condition of viscoelastic materials, performance evaluation of the asphalt-concrete trackbed system was used to deal with the dynamic amplification factors; numerical results using isotropic-elastic materials in the FE analysis are presented.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3A
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• pp.465-471
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• 2006

To describe hysteretic behavior of steel structures under dynamic loading such as earthquake, the dynamic cyclic plasticity model considering stress-strain relationship and characteristics of used steel materials under static-dynamic deforming is required. In this paper, mechanical characteristics and stress-strain relationship of SM490 was clarified by carrying out static-dynamic monotonic and cyclic loading test. A dynamic cyclic plasticity model of SM490 was proposed based on the test results and applied 3-dimensional finite element analysis using finite deformation theory. An analytical method developed by the authors was verified validity and accuracy by comparing both analysis and test results. The comparison result shows that the analytical method developed by the authors can predict static-dynamic hysteretic behavior of steel structures with accuracy.

• Computational Structural Engineering
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• v.11 no.4
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• pp.321-330
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• 1998

막구조의 초기형상을 결정하기 위하여 막요소의 기하학적 비선형을 고려한 평형방정식을 유도하고, 등장력곡면(equally stressed surface)을 결정하기 위한 알고리즘을 정식화한다. 막구조는 대변형에 의한 기하학적 비선형성을 포함하고, 막구조의 특성상 초기장력에 의한 초기변형을 고려해야 하므로, 본 논문에서는 막구조와 같은 인장구조물의 비선형 수치해석을 수행하기 위한 해석기법으로써, 동적이완법(Dynamic Relaxation Method)에 대한 해석알고리즘을 적용하고, 이 방법에 의해 수행한 해석결과를 검토함으로써 막구조 해석에 적용 가능한 수치해석기법을 제시하고, 수치해석에 대한 예를 통해 본 해석법의 타당성을 검증한다.