• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.252-255
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• 2004

Design modification of the stamping die for the upper member of a front end module carrier is carried out in order to improve the feeling qualify of the final product. The small inferiority induced by wrinkling near the wall of the FEM upper member has been inspected after the draw-forming process. The finite element simulation shows that the excess metal is developed by the irregular contact of the blank the tool and it remains after the final stroke. This paper proposes two guidelines for the modification: one is to add the draw-bead; and the other is to modify the tool shape such as the forming shape at the wall. Simulation results show that the proposed guidelines both guarantee the improved feeling quality.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.421-428
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• 1999

The elastic critical load of a slender compression member plays an important role when the proper design of that member is required. For the tapered compression members, however, there are cases when the conventional neutral equililbrium or energy method can't be applied to the determination of critical loads of those members. In this paper, finite element method is applied to the approximate determination of the symmetrically tapered bars. Here in this paper, the bars are assumed to take sinusoidally changing shapes along their axes. The parameters considered in this study are taper parameter, $\alpha$ and the sectional property parameter, m. The computed results by finite element method are represented in the forms of algebraic equations. Regression technique is employed to determine the coefficients of algebraic equations. The critical loads estimated by the proposed algebraic equations coincide fairly well with those of finite element method.

• 한국전산구조공학회논문집
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• 제23권5호
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• pp.455-463
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• 2010

본 연구는 다양한 건설 구조물 중 휨 응력을 받는 부재인 슬래브, 거더 등에 FRP 박스 부재를 적용하기 위한 기초 실험적 연구이다. FRP 부재를 제작하여 FRP 박스 부재의 대형단면으로서의 연결성능 특징을 분석하기 위하여 다양한 조건으로 실험을 수행하였다. FRP 박스 부재의 연결방법에는 화학적 연결, 기계적 연결, 혼합적 연결방법을 이용하여 가로방향과 세로방향에 대해 각각 연결실험을 실시하였다. 실험결과 우레탄+볼트 2개+쉬트를 이용한 방법이 FRP 박스 부재의 가장 이상적인 연결방법이었으며, 유한요소해석을 실시하여 거동을 검토하였다.

• Steel and Composite Structures
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• 제10권1호
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• pp.45-67
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• 2010

Composite steel-concrete structures are employed extensively in modern high rise buildings and bridges. This concept has achieved wide spread acceptance because it guarantees economic benefits attributable to reduced construction time and large improvements in stiffness. Even though the combination of steel and concrete enhances the strength and stiffness of composite beams, the time-dependent behaviour of concrete may weaken the strength of the shear connection. When the concrete loses its strength, it will transfer its stresses to the structural steel through the shear studs. This behaviour will reduce the strength of the composite member. This paper presents the development of an accurate finite element model using ABAQUS to study the behaviour of shear connectors in push tests incorporating the time-dependent behaviour of concrete. The structure is modelled using three-dimensional solid elements for the structural steel beam, shear connectors, concrete slab and profiled steel sheeting. Adequate care is taken in the modelling of the concrete behaviour when creep is taken into account owing to the change in the elastic modulus with respect to time. The finite element analyses indicated that the slip ductility, the strength and the stiffness of the composite member were all reduced with respect to time. The results of this paper will prove useful in the modelling of the overall composite beam behaviour. Further experiments to validate the models presented herein will be conducted and reported at a later stage.

• 전산구조공학
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• 제6권4호
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• pp.99-105
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• 1993

본 연구에서는 보울트-너트 체결기구의 체결장력 설계(Pre-Load Design)시 중요한 인자의 하나인 체결체의 강성(Stiffness)을 유한요소법을 이용하여 해석하였다. 비선형 간극요소(Non-linear Gap Element)와 최적화 기법(Optimization Technique)을 도입하여 유한요소해석 과정에서 요구되는 경계조건(Boundary Condition)의 설정과정을 일반화하였으며, 체결체간의 기밀성 상실 현상을 입증하였다. 변형량과 응력분포로부터 체결체의 강성을 해석하고, 기존의 경험식의 적용범위를 검토하였다.

• 한국전산구조공학회논문집
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• 제12권4호
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• pp.525-535
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• 1999

본 연구는 거더 상면에 연장 형성된 수직돌출부의 양측에 상부 플랜지를 가지는 주형과 바닥 면에 모서리보다 형성되어 있는 바닥 판이 현장에서 그라우팅에 의한 전단 키로 연결되어 교량구조물을 형성하는 새로운 형태의 바닥 판 조립식 교량구조를 제안하고 그에 따른 정적실험 및 유한요소해석을 통해 구조거동을 분석하여 실제 적용가능성을 입증하는데 목적이 있다. 먼저 주형과 바닥 판의 연결부에서 발생하는 구조적 평형조건을 입증하기 위해 주형과 바닥 판의 연결부에 스프링 효과를 이용한 유한요소해석을 통해 바닥 판에서 발생하는 부재 력을 해석하였다. 이때 바닥 판에 가장 불리하게 작용하는 하중위치를 관찰하였으며 이를 실제 정적실험 모델과 동일한 유한요소해석결과와 실험결과의 비교로부터 바닥 판 조립식교량은 설계하중 하에서 충분한 저항내력을 확보하고 있는 것으로 나타났다. 또한 정적실험에서의 내·외측 주형의 처짐과 유한요소해석결과를 비교한 결과로부터 실험에 의한 처짐이 유한요소해석결과보다 작게 나타났으며 이러한 결과로부터 바닥 판 조립식교량의 실제 강성은 충분한 것으로 증명되었다. 또한 바닥 판 조립식교량에서 주형사이에 가로 보의 설치 갯수에 따른 하중 횡 분배효과 및 바닥 판이 합성된 후의 합성효과 등을 관찰하기 위한 유한 요소해석을 수행하였다. 하중 횡 분배효과는 편심 하중 재하 시에 가로 보의 개수가 3개로 증가하였을 때 가장 현저하게 나타났으며 합성단면에서의 하중 횡 분배는 바닥 판 연결에 의한 합성효과로 인해 비 합성 단면에서의 하중 횡 분배의 약1/2의 크기로써 효과적인 합성효과가 발생하는 것으로 나타났다.

• Structural Engineering and Mechanics
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• 제31권3호
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• pp.297-314
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• 2009

When the temperature of a structure varies, there is a tendency to produce changes in the shape of the structure. The resulting actions may be of considerable importance in the analysis of the structures having non-prismatic members. Therefore, this study aimed to investigate the modeling, analysis and behavior of the non-prismatic members subjected to temperature changes with the aid of finite element modeling. The fixed-end moments and fixed-end forces of such members due to temperature changes were computed through a comprehensive parametric study. It was demonstrated that the conventional methods using frame elements can lead to significant errors, and the deviations can reach to unacceptable levels for these types of structures. The design formulas and the dimensionless design coefficients were proposed based on a comprehensive parametric study using two-dimensional plane-stress finite element models. The fixed-end actions of the non-prismatic members having parabolic and straight haunches due to temperature changes can be determined using the proposed approach without necessitating a detailed finite element model solution. Additionally, the robust results of the finite element analyses allowed examining the sources and magnitudes of the errors in the conventional analysis.

• Steel and Composite Structures
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• 제23권2호
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• pp.217-228
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• 2017

Braces are one of the retrofitting systems of structure under earthquake loading. Buckling restrained braces (BRBs) are one of the very efficient braces for lateral loads. One of the key needs for a desirable and acceptable behavior of buckling-restraining brace members under intensive loading is that it prevents total buckling until the bracing member tolerates enough plastic deformation and ductility. This paper presents the results of a set of analysis by finite element method on buckling restrained braces in which the filler materials within the restraining member have been removed. These braces contain core as the conventional BRBs, but they have a different buckling restrained system. The purpose of this analysis is conducting a parametric study on various empty spaces between core and restraining member, the effect of friction between core and restraining member and applying initial deformation to brace system to investigate the global buckling behavior of these braces. The results of analysis indicate that the flexural stiffness of restraining member, regardless of the amount of empty space, can influence the global buckling behavior of brace significantly.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.898-905
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• 2006

In the present paper, for a quantitative assessment of early-age cracking in an RC wall, an improved analytical model is proposed. First of all, a three-dimensional finite element model for the analysis of stresses due to hydration heat and differential drying shrinkage is introduced. A discrete steel element derived using the equivalent nodal force concept is used to simulate reinforcing steels, embedded in a concrete matrix. In advance, to quantitatively calculate the cracking potential, an analytical model that can estimate the post-cracking behavior in an RC tension member is proposed Subsequent comparisons. of analytical results with test results verify that the combined use of both the finite element model for the stress analysis as well as the analytical model for the estimation of the post-cracking behavior in an RC tension member make it possible to accurately predict the cracking ,behavior of RC walls.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1995년도 가을 학술발표회 논문집
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• pp.68-75
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• 1995

In recent year, column member is used for square hollow section(5.H.5) and beam member is used for H-section. But 5.H.5 column has vulnerability because of low flexural stiffness between column and beam connection joints. To reinforce this vulnerability, 5.H.5 column filled with concrete and concrete slab connection compounded with H-beam is developed in many ways. In this paper, modelling of predicting behavior of various types of connections is studied using finite element method. k order to simulate the actual behavior, a three-dimensional modelling is used. A simple efficient contact algorithm with a new gap element is employed to simulate the interaction between 5.H.5 column and concrete, The modelling result$ are compared with the experimental results.