• Structural Engineering and Mechanics
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• 제49권6호
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• pp.793-810
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• 2014

This research work deals with the development of a new Triangular finite element for the linear analysis of plate bending with transverse shear effect. It is developed in perspective to building shell elements. The displacements field of the element has been developed by the use of the strain-based approach and it is based on the assumed independent functions for the various components of strain insofar as it is allowed by the compatibility equations. Its formulation uses also concepts related to the fourth fictitious node, the static condensation and analytic integration. It is based on the assumptions of tick plate.s theory (Reissner-Mindlin theory). The element possesses three essential external degrees of freedom at each of the four nodes and satisfies the exact representation of the rigid body modes of displacements. As a result of this approach, a new bending plate finite element (Pep43) which is competitive, robust and efficient.

• Structural Engineering and Mechanics
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• 제45권2호
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• pp.169-182
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• 2013

The mechanical behavior of rectangular foundation plates with perimetric beams and internal stiffening beams of the plate is herein analyzed, taking the foundation design into account. A series of dimensionless parameters related to the geometry of the studied elements were defined. In order to generalize the problem statement, an initial settlements was considered. A numeric procedure was developed for the resolution by means of the Finite Differences Method that takes into account the stiffness of the plate, the perimetric and internal plate beams and the soil reaction module. Iterative algorithms were employed which, for each of the analyzed cases, made it possible to find displacements and reaction percentages taken by the plate and those that discharge directly into the perimetric beams, practically without affecting the plate. To enhance its mechanical behavior the internal stiffening beams were prestressed and the results obtained with and without prestressing were compared. This analysis was made considering the load conditions and the soil reaction module constant.

• 대한수학회보
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• 제58권4호
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• pp.1031-1038
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• 2021

The main aim of this article is to study quantitative structure of finite simple exceptional groups F₄(2ⁿ) with n > 1. Here, we prove that the finite simple exceptional groups F₄(2ⁿ), where 2⁴ⁿ + 1 is a prime number with n > 1 a power of 2, can be uniquely determined by their orders and the set of the number of elements with the same order. In conclusion, we give a positive answer to J. G. Thompson's problem for finite simple exceptional groups F₄(2ⁿ).

• 대한수학회보
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• 제52권2호
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• pp.367-376
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• 2015

In this paper, we classified finite p-groups G such that $$C_G(x)/<x>$$ is cyclic for all non-central elements $x{\in}G$. This solved a problem proposed By Y. Berkovoch.

• Korean Journal of Mathematics
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• 제21권3호
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• pp.331-344
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• 2013

In the present article, we describe specific elements in a motivic cohomology group $H^1_{\mathcal{M}}(Spec\mathbb{Q}({\zeta}_l),\;\mathbb{Z}(2))$ of cyclotomic fields, which generate a subgroup of finite index for an odd prime $l$. As $H^1_{\mathcal{M}}(Spec\mathbb{Q}({\zeta}_l),\;\mathbb{Z}(1))$ is identified with the group of units in the ring of integers in $\mathbb{Q}({\zeta}_l)$ and cyclotomic units generate a subgroup of finite index, these elements play similar roles in the motivic cohomology group.

• 대한기계학회논문집
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• 제15권5호
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• pp.1601-1610
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• 1991

본 연구에서는 3차원 스트레칭 문제의 2차원화가 가능한 주요 단면에 대해서 박막요소와 적층 셸(degenerated shell) 요소를 혼합하여 사용하는 선택적 M/S 방법을 이용하여 2차원 문제로 해석하였다. M/S변환 조건으로는 변형형상의 기하학적 조건 을 고려하였다.

• Computers and Concrete
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• 제1권3호
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• pp.285-302
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• 2004

A FE-(FE-HE)-BE procedure is presented for dynamic analysis of concrete arch dams. In this technique, dam body is discretized by solid finite elements, while the reservoir domain is considered by a combination of fluid finite elements and a three-dimensional fluid hyper-element. Furthermore, foundation rock domain is handled by three-dimensional boundary element formulation. Based on this method, a previously developed program is modified, and the response of Morrow Point arch dam is studied for various conditions. Moreover, the effects of canyon shape on response of dam, is also discussed.

• 전산구조공학
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• 제7권2호
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• pp.139-146
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• 1994

볼트 접합부의 정확한 해석을 위하여 접합 요소와 볼트 요소 및 쉘 요소를 사용한 방법을 개발하였다. 접합면을 단순하게 이상화시키는 접합 요소와 장력을 갖는 볼트 요소를 도입하였고, 전체적인 계산과정은 2단계, 즉 제안된 방법에 의한 초기 강성의 결정과 뉴턴-랩슨법에 근거하는 호장법을 이용한 비선형 거동의 추적으로 구분하여 행함으로써 계산의 효율성을 증대시켰다. 앵글을 사용한 반강접 접합부와 모멘트 판을 사용한 접합부를 해석하여 기존 실험 및 해석과 비교함으로써 제안한 방법의 정확성과 적용성을 입증하였다. 또한 볼트 접합부의 정확한 해석을 위해서는 접합면에서 발생하는 미끄럼짐의 고려가 반드시 필요하며 접합부를 구성하는 판재의 3차원적인 변형의 해석도 무시할 수 없는 역할을 하는 사실을 보여주었다.

• 대한토목학회논문집
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• 제26권3A호
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• pp.439-445
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• 2006

터널과 같이 구조물의 크기가 매질의 영역에 비하여 상대적으로 작은 경우와 같은 무한영역의 문제는 유한요소법을 적용하여 해석할 수 있으나 해석의 정밀도를 높이기 위해서는 해석영역을 크게 선정하게 되어 계산량이 증가하고, 인위적인 경계조건에 의한 오차의 영향을 피할 수 없다. 이를 개선하기 위해 관심영역은 유한요소로 모델링하고 무한영역은 무한요소로 모델링하는 혼합법을 적용하면 보다 효과적이다. 본 연구에서는 다양한 감쇠함수를 적용한 등매개변수형 무한요소를 제안하였고 매개변수해석을 통하여 터널해석에 적합한 감쇠함수의 특성치를 제시하였다. 또한 이를 적용한 3차원 혼합모델이 터널 해석에 유효함을 입증하였다.

• 대한수학회보
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• 제42권3호
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• pp.433-441
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• 2005

The concepts linearly independent elements and u-linearly independent elements in an N-group G where N is a near-ring, were introduced and studied. A few important results in the theory of vector spaces were generalized to N-groups.