• 대한조선학회지
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• 제19권2호
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• pp.27-31
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• 1982

The practical utilization of the frequency and normal mode equations of uniform Timoshenko beams such as those presented by Huang is not simple due to their highly trancendental nature. In this note largely simplified equations obtained for the fixed-fixed and the free-free boundary conditions, the modes of which are separable into symmetric modes and antisymmetric ones, are given. Numerical results obtains for six common-type boundary conditions show that the quantitative measure of the effect of rotary inertia and shear deformation on the natural frequency is greatly dependent upon the boundary conditions as well as the order number.

• 한국공간구조학회논문집
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• 제2권4호
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• pp.29-36
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• 2002

The responses of composite laminated beams modeled with finite element and excited by stochastic loading are studied. The cantilevered laminated beam having a 5 ply configuration is considered. The beam is 1m long, 0.1m wide, and 0.02m thick, yielding a length to thickness ratio of L/h=50. The laminated beams was assumed to be made of Born Epoxy. The four nodes at the free end of the cantilever were loaded with identical zero-mean white noise excitations. Stress and failure analysis loaded with identical zero-mean white noise excitations is carried out. Along with the obtained results, comparison and discussion are presented for the cases of symmetric-ply, antisymmetric-ply, angle-ply, and cross-ply laminated beams.

• 한국재난정보학회 논문집
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• 제12권1호
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• pp.62-68
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• 2016

본 연구에서는 충격 문제를 거론하며 Mindlin 판 이론을 확장한 1차 전단 변형 이론에 근거하여 충격 하중을 받는 적층판의 응답 특성의 해석을 목적으로 아이소파라메트릭요소에 의한 정식화를 시도한다. 유한요소법을 이용하여 역대칭 Angle-Ply 적층판의 사각판과 원형판의 수치해석을 통해 정적해석과 동적해석의 결과를 도출하여 각 변위에 대한 분석결과를 비교한다.

• 한국자동차공학회논문집
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• 제3권3호
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• pp.29-36
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• 1995

The present paper deals with the crushing characteristics of double hatted-section tube used in body structure of passenger car. Being crushed, a double hatted-section tube shows symmetric or antisymmetric buckling mode according to section aspect ratio and flange size. Zone of buckling mode is shown by numerical methods. It is supposed that crippling behavior of double hatted-section tube corresponds with rectangular tube without flange. Crippling plate coefficient is also calculated when section aspect ratio of tube is higher than one.

• 대한기계학회논문집A
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• 제21권3호
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• pp.414-422
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• 1997

The characteristics on the extension of the CED(Crack Energy Density) concept to the interface kinked crack problems in a dissimilar are examined. Each mode contributions of CED are found by symmetric and antisymmetric conponents and domain independent integrals. Finite element calculation is carried out to simulate the interface kinked crack growth on a bimaterial. The focus is the establishment of fracture criterion with CED and finding the orientation of crack extension. From the results, a prediction about the extension behavior of an interface kinked crack can be done. And we show that CED can be a parameter to indicate fracture criterion at an interface kinked crack.

• 대한기계학회논문집
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• 제17권8호
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• pp.2051-2060
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• 1993

A finite element program using degenerated shell element was developed to solve the geometric, material and combined nonlinear behaviors of composite laminated shell. The total Lagrangian method was implemented for geometric nonlinear analysis. The material nonlinear behavior was analyzed by considering the matrix degradation due to the progressive failure in the matrix and matrix-fiber interface after initial failure. The result of the geometric nonlinear analysis showed good agreement with the other exact and numerical solutions. The results of the combined analyses considered both geometric and material nonlinear analyses were compared with the experiments in which internal pressure was applied to the filament wound antisymmetric tubes.

• 소음진동
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• 제11권2호
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• pp.315-322
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• 2001

This paper is focused on the frictionally induced thermoelastic instability (TEI) in automotive disk brakes. This instability leads to the formation of localized high temperature contact regions known as hot spots. This article investigates the themoelastic instability in automotive disk brake systems consisting of a finite thickness layer (disk) and two half-planes (pads) using a perturbation method. The antisymmetric mode involves hot spots located alternately on two sides of the disk. As a result the circumferentially periodic hot spots produce rotor surface distortion and Induce low frequency vibration. Also the effects of system parameters on the critical speed for TEI are investigated.

• Structural Engineering and Mechanics
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• 제26권2호
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• pp.151-162
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• 2007

Rigorous analytical solutions are obtained for the plane stress problem of a rectangular plate subjected to non-linearly distributed bending loads on two opposite edges. They are then used in a Galerkin type solution to obtain the corresponding convergent buckling loads. It is shown that the critical bending moment depends significantly on the actual edge load distribution and further the number of nodal lines of the buckled configuration can also be different from that corresponding to a linear antisymmetric distribution of the bending stresses. Results are tabulated for future use while judging approximate numerical solutions.

• 대한화학회지
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• 제39권3호
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• pp.213-217
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• 1995

수용액상에서 BUDDA(Butyldithiodiacetic acid), BMDDA(Benzmethyldithiodiac-etic acid), CHDDA(Cyclohexyldithiodiacetic acid)의 IR 스펙트라는 다양한 pH값에서 보고되어진다. 이온화된 carboxyl group과 비이온화된 carboxyl group의 비대칭 신축진동 흡수띠 차이를 이용하여 free-ligand의 구조를 추정한다. 또한 이들 연구의 접근은 리간드의 IR 스펙트라와 전위차 적정법을 이용하여 얻어진 $pk_a$값을 비교함으로서 설명된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.703-709
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• 2001

In this paper, we analyzed the laminated composite sandwich plate structure of truss core with changing values of the designing parameters. As a result, in designing parameters of that, the more height and thickness of the laminated composite plate's core, the more increase of natural frequency. In this type of structure, in the case of applying core of the laminated composite plate and antisymmetric stacking, natural frequency has high value and we calculated the optimum angle-ply making natural frequency maximum. Natural frequency of CFRP is higher than that of GFRP. Both are materials of the laminated composite plate. The mode shapes are various along with the angle-ply of the laminated composite plate.