• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.226-233
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• 1999

When we numerically model the bridge under seismic condition, the full model combining the super-structure and the sub-structure is considered for the more accurate results than the separate model. In this case, the super-structure is connected with the sub-structure by the elastic pad shoe that is difficult to model, because it has the three translational elastic stiffness and the three rotational elastic stiffness. The two-node General Link element is derived in finite element equation representing such a pad shoe, and it is verified by comparing the one General Link element model with the corresponding three legacy spring element model. It is easy to model the pad shoe, if the General Link finite element is used. And the seismic analysis result of the bridge full model structure, which is modeled with the General Link element, has been compared with the one of the separate model structure. The present study gives. more conservative result than that of the separate model, which does not consider the dynamic behaviour of the sub-structure.

• International Journal of High-Rise Buildings
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• v.4 no.1
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• pp.75-83
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• 2015

In the present study, the preliminary results of a large-scale seismic response analysis of a super-high-rise steel frame considering soil-structure interaction are presented. A seismic response analysis under the excitation of the JR Takatori record of the 1995 Hyogoken-Nanbu earthquake is conducted. Precise meshes of a 31-story super-high-rise steel frame and a soil region, which are constructed completely of hexahedral elements, are generated and combined. The parallel large-scale simulation is performed using K computer, which is one of the fastest supercomputers in the world. The results are visualized using an offline rendering code implemented on K computer, and the feasibility of using a very fine mesh of solid elements is investigated. The computation performance of the analysis code on K computer is also presented.

• Transactions of Materials Processing
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• v.17 no.8
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• pp.600-606
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• 2008

In closed-die hot forging, a billet is formed in dies such that the flow of metal from the die cavity is restricted. Some parts can be forged in a single set of dies, whilst others, due to shape complexity and material flow limitations, must be shaped in multi sets of dies. The purpose of a performing operation is to distribute the volume of the parts such that material flow in the finisher dies will be sound. This study focused on the design of preforms, flash thickness and land width by theoretical calculation and finite element analysis, to manufacture the super hot forging product, 70MC type piston crown used in marine engine. The optimal design of preforms by the finite element analysis and the design experiment achieves adequate metal distribution without any defects and guarantees the minimum forming load and fully filling of the cavity of the die for producing the large piston crown. The maximum loads obtained by finite element analysis are compared with the results of experiments. The loads of the analysis have good agreements with those of the experiment. Results obtained using DEFORM-2D enable the designer and manufacturer of super hot forging dies to be more efficient in this field.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.78-83
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• 2009

In this study, computer applied engineering (CAE) techniques are fully used to conduct structural and dynamic analyses of a whole huge wind turbine system including composite blades, tower and nacelle. For this study, computational fluid dynamics (CFD) is used to predict aerodynamic loads of the rotating wind-turbine blade model. Multi-body dynamic structural analyses are conducted based on the non-linear finite element method (FEM) by using super-element method for composite laminates blade. Three-dimensional finite element model of a wind turbine system is constructed including power train(main shaft, gear box, coupling, generator), bedplate and tower. The results for multi-body dynamic simulations on the wind turbine's critical operating conditions are presented in detail.

• Structural Engineering and Mechanics
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• v.69 no.5
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• pp.557-566
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• 2019

The reservoir basin bedrock produced significant impact on the long-term service safety of super-high arch dams. It was important for accurately identifying geomechanical parameters and its evolution process of reservoir basin bedrock. The deformation modulus mechanism research methods of reservoir basin bedrock deformation modulus for super-high arch dams was carried out by finite element numerical calculation of the reservoir basin bedrock deformation and in-situ monitoring data analysis. The deformation modulus inversion principle of reservoir basin bedrock in a wide range was studied. The convergence criteria for determining the calculation range of reservoir basin of super-high arch dams was put forward. The implementation method was proposed for different layers and zones of reservoir basin bedrock. A practical engineering of a super-high arch dam was taken as the example.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.151-162
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• 2000

This study is concerned with computerized multi-level substructuring methods and stress analysis of coil springs. The purpose of substructuring methods is to reduce computing time and capacity of computer memory by multiple level reduction of the degrees of freedom in large size problems that are modeled by three dimensional continuum finite elements. In this paper, the spring super element developed is investigated with tension, torsion, and bending of a cylindrical bar in order to verify its accuracy and efficiency for the multi-level substructuring method. And then the algorithm is applied to finite element analysis of coil springs. The result demonstrates the validity of the multi-level substructuring method and the efficiency in computing time and memory by providing good computational results in coil spring analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.271-274
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• 2007

The finite element linear buckling analysis of folded plate structures using adaptive h-refinement methods is presented in this paper. The variable-node flat shell element used in this study possesses the drilling D.O.F. which, in addition to improvement of the element behavior, permits an easy connection to other elements with six degrees of freedom per node. The Box-typed structures can be analyzed using these developed flat shell elements. By introducing the variable node elements some difficulties associated with connecting the different layer patterns, which are common in the adaptive h-refinement on quadrilateral mesh, can be overcome. To obtain better stress field for the error estimation, the super-convergent patch recovery is used. The convergent buckling modes and the critical loads associated with these modes can be obtained.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.1
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• pp.67-74
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• 1999

본 문에서는 선체 중앙부의 유한요소 모델링과 진동해석이 수행되었다. 횡부재와 종통부재가 만나 3차원적으로 연결되어 있는 선체구조는 복잡한 구조적 특성 때문에 모델링에 많은 노력이 필요하다. 선수, 선미부에 비해 비교적 부재간의 접속이 간단한 중앙평행부의 진동해석과 같은 경우에는 모델링 기법을 개발해 사용할 수도 있다. 중앙부 횡부재와 종통부재가 만나는 부분의 접속성과 형상표현을 위해 keypoint, super element(SE) 개념을 도입하였고 형성된 SE 들을 isoparametric mapping 기법을 접속된 3차원 부재용으로 개선하여 유한요소로 분할하였다. 진동해석용으로 형성된 선체중앙부 요소망을 ANSYS로 가시화하였고 자유진동해석을 수행하였다.

• Structural Engineering and Mechanics
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• v.24 no.2
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• pp.269-273
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• 2006

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.1
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• pp.1-10
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• 2004

Adaptive finite element analysis, in which its solution error meets with the user defined allowable error, is recently used to improve the reliability of finite element analysis results. This adaptive analysis is composed of two procedures; one is the error estimation of an analysis result and the other is the reconstruction of finite elements. In the (p-method, an element size is controlled by relocating of nodal positions (r-method) and the order of an element shape function is determined by the hierarchical polynomial (p-method) corresponding to the clement solution error by the enhanced SPR. In order to show the effectiveness and the accuracy of the suggested rp-method, various numerical examples were analyzed and these analysis results were examined by comparing with those obtained by the existed methods.