• 토지주택연구
• /
• 제7권1호
• /
• pp.31-41
• /
• 2016

이 논문은 최근 천영수 등(2011)에 의하여 제안된 벽체 단부 횡보강상세를 지닌 벽체를 중심으로 벽체의 구조성능 영향 변수들을 대상으로 한 실험결과와 그에 따른 내진거동 및 이력특성을 제시하고 있다. 제시된 결과는 동 벽체의 비선형이력특성을 규명함으로써 향후 성능기반설계의 적용을 위한 기초자료를 제공하게 될 것이다. 실험결과, 제안된 횡보강 상세를 채용한 실험체의 균열 및 파괴 양상은 축력과 내진철근의 적용 여부와 상관없이 유사한 경향을 나타내었으며, 기준에서 제시하고 있는 설계식에 의하여 실험체의 최대강도를 잘 예측할 수 있는 것으로 나타났다. 또한, 축력이 높을 수록 초기강성과 최대강도는 증가하나 변형능력은 떨어지는 경향이 있어 고 축력으로 인한 변형능력 감소에 대한 고려가 필요할 것으로 보이며, 고 축력이 작용하는 벽체의 경우 내진철근의 사용이 변형능력의 확보라는 관점에서 매우 효과적인 방안이 될 것으로 보임으로 가능하다면 소성힌지 영역은 내진철근을 사용한 경계요소로 보강하는 것이 바람직한 것으로 판단된다.

• Structural Engineering and Mechanics
• /
• 제54권3호
• /
• pp.393-417
• /
• 2015

In this paper an 8-node quadrilateral assumed stress hybrid Mindlin plate element with $39{\beta}$ is presented. The formulation is based on complementary energy principle. The proposed element is free of shear locking and is capable of passing all the patch tests, especially the non-zero constant shear enhanced patch test. To accomplish this purpose, special attention is devoted to selecting boundary displacement interpolation and stress approximation in domain. The arbitrary order Timoshenko beam function is successfully used to derive the boundary displacement interpolation. According to the equilibrium equations, an appropriate stress approximation is rationally derived. Particularly, in order to improve element's accuracy, the assumed stress field is derived by employing $39{\beta}$ rather than conventional $21{\beta}$. The resulting element can be adopted to analyze both moderately thick and thin plates, and the convergence for the very thin case can be ensured theoretically. Excellent element performance is demonstrated by a wide of experimental evaluations.

• 소음진동
• /
• 제3권2호
• /
• pp.163-167
• /
• 1993

Suction and discharge valves of special type refrigerant compressor are designed by finite element method for effective valve design development procedure. It is well known that valve dynamic characteristics, for example, the natural frequencies and vibration modes, are necessary for the computer simulation of compressor valve dynamics, the analysis of flow patterns, noise, impact stresses and their propagation phenomena. This paper has analysed the natural frequencies and vibration modes for the first three orders under the given special boundary conditions and the experiments are conducted by laser holography. And also stress distribution is analysed and experiment by strain gage is followed.

• Structural Engineering and Mechanics
• /
• 제30권3호
• /
• pp.279-296
• /
• 2008

This paper presents an exact integration for the hypersingular boundary integral equation of two-dimensional elastostatics. The boundary is discretized by straight segments and the physical variables are approximated by discontinuous quadratic elements. The integral for the hypersingular boundary integral equation analysis is given in a closed form. It is proven that using the exact integration for discontinuous boundary element, the singular integral in the Cauchy Principal Value and the hypersingular integral in the Hadamard Finite Part can be obtained straightforward without special treatment. Two numerical examples are implemented to verify the correctness of the derived exact integration.

• 비파괴검사학회지
• /
• 제31권6호
• /
• pp.650-655
• /
• 2011

Analysis of two-dimensional Rayleigh wave scattering pattern by a surface defect is studied through modified boundary element method. BEM proposed in this paper has special treatment at each end of boundary which should have the Rayleigh wave go away without any generation of virtual reflections. It is shown that treatment for truncated boundary which is used to model two-dimensional Rayleigh waves' behavior in an elastic half-space is successfully implemented. To check numerical results' accuracy, time domain IFFT signal of the displacements is presented. Improvement on getting rid of unwanted influence of truncated boundary induced by 2-D Rayleigh waves on a flat surface of an elastic half-infinite medium is shown. As a final goal, the numerical results of Rayleigh wave scattering trend are plotted and they are compared with theoretical curves to prove its accuracy.

• 콘크리트학회논문집
• /
• 제25권3호
• /
• pp.271-281
• /
• 2013

구조형식별로 구조물의 안정성 확보를 위해 KBC2009에 새로이 도입된 높이제한에 따라, 내진설계범주D에 해당되는 60 m 이상의 RC 구조물을 계획할 경우 특수전단벽을 의무적으로 사용해야 한다. 그러나 특수전단벽의 엄격한 횡보강 배근상세는 시공성 및 경제성에 부정적 영향을 미칠 것으로 예상된다. 그래서 이 연구에서는 현 규준에 따른 특수전단벽보다 완화된 배근 상세를 갖는 특수전단벽을 제안하고, 특수전단벽과의 성능 비교를 위하여 각각 두 개의 실험체를 제작하고 횡방향 반복 하중실험을 실시하였다. 또한 그 실험 결과를 반영한 보통전단벽, 특수전단벽, 완화된 특수전단벽 구조시스템의 해석모델을 설계하여 FEMA P695에 따른 방법론으로 내진성능평가를 실시하였다.

• 한국생산제조학회지
• /
• 제6권1호
• /
• pp.59-68
• /
• 1997

Recently, the cases of using bonded dissimiliar materials which have each of the different components tend to increase for the purpose of developing new materials and using the special objects in the field of industry. Among the cases the strength evaluation of the joining materials of vehicle engine and the structural materials with ceramic/metal bonded joints becomes more important. But the residual stress occurs, because the joining of ceramics and metals is performed in extremely high temperature. It becomes a dominant cause to reduce the strength of the ceramic/metal bonded joints. In this paper, strength evaluation method of ceramic/metal bonded joints considering stress singularity was investigated by boundary element method and 4-point bending test. An advanced method of quantitative strength evaluation for ceramin/metal bonded joints is to be suggested.

• 대한조선학회논문집
• /
• 제31권2호
• /
• pp.45-56
• /
• 1994

2차원 수중익 주위의 비선형 자유표면 유동을 시간영역에서 시뮬레이션할 수 있는 수치해법이 개발되었다. 본 수치해법은 고차 스펙트럴법과 경계요소법을 조합한 스펙트럴/경계요소법(spectral/boundary-element method)이며, 자유표면은 고차 스펙트럴법에 의해 그리고 수중익과 후류 보오텍스는 경계요소법에 의해 다루어 진다. 본 방법은 자유표면과 수중익의 비선형/비정상 상호작용문제에 폭넓게 적용될 수 있으며, 특히 스펙트럴법을 사용하므로 자유표면 유동을 매우 효율적으로 다룰 수 있다. 적용예로 정지상태에서 출발하여 자유표면 근처에서 균속 전진운동 또는 전진 및 동요운동을 하는 경우가 다루어 졌고, 자유표면파와 동유체력에서의 비선형/비정상 효과들이 보여지고 있다. 비정상해의 특수한 경우로 얻어지는 정상상태의 계산결과들이 다른 이론 또는 실험결과들과 비교되었으며, 좋은 일치를 보이고 있다.

• Structural Engineering and Mechanics
• /
• 제25권5호
• /
• pp.501-518
• /
• 2007

In this work, a new approach is developed for dynamic analysis of a composite beam with an interply crack, based on finite element solution of partial differential equations with the use of the COMSOL Multiphysics package, allowing for fast and simple change of geometric characteristics of the delaminated area. The use of COMSOL Multiphysics package facilitates automatic mesh generation, which is needed if the problem has to be solved many times with different crack lengths. In the model, a physically impossible interpenetration of the crack faces is prevented by imposing a special constraint, leading to taking account of a force of contact interaction of the crack faces and to nonlinearity of the formulated boundary value problem. The model is based on the first order shear deformation theory, i.e., the longitudinal displacement is assumed to vary linearly through the beam's thickness. The shear deformation and rotary inertia terms are included into the formulation, to achieve better accuracy. Nonlinear partial differential equations of motion with boundary conditions are developed and written in the format acceptable by the COMSOL Multiphysics package. An example problem of a clamped-free beam with a piezoelectric actuator is considered, and its finite element solution is obtained. A noticeable difference of forced vibrations of the delaminated and undelaminated beams due to the contact interaction of the crack's faces is predicted by the developed model.

• 한국지진공학회논문집
• /
• 제17권1호
• /
• pp.43-51
• /
• 2013

In this paper, analytical models for reinforced concrete shear wall systems designed based on Korean Building Code (KBC2009) are proposed, which have special and semi-special seismic details and are compared with experimental results for a verification of analytical models. In addition, semi-special seismic details aimed to improve constructability and enhance economic efficiency were proposed and evaluated. The analytical models were performed based on nonlinear static and dynamic analysis. Through the nonlinear analyses, two seismic details showed the similar seismic behavior from the cyclic test and the analytical models for the two different seismic details represented the behavior in terms of the initial stiffness, maximum strength and strength degradation. And newly proposed seismic details(semi-special) provided with similar hysterestic behavior as well as the maximum drift.