• Smart Structures and Systems
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• 제21권1호
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• pp.113-122
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• 2018

In this article, an exact analytical solution for mechanical buckling analysis of magnetoelectroelastic plate resting on pasternak foundation is investigated based on the third-order shear deformation plate theory. The in-plane electric and magnetic fields can be ignored for plates. According to Maxwell equation and magnetoelectric boundary condition, the variation of electric and magnetic potentials along the thickness direction of the plate is determined. The von Karman model is exploited to capture the effect of nonlinearity. Navier's approach has been used to solve the governing equations for all edges simply supported boundary conditions. Numerical results reveal the effects of (i) lateral load, (ii) electric load, (iii) magnetic load and (iv) higher order shear deformation theory on the critical buckling load have been investigated. These results must be the analysis of intelligent structures constructed from magnetoelectroelastic materials.

• 대한전자공학회논문지
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• 제25권4호
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• pp.366-371
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• 1988

A parallel-plate waveguide with a slit in its upper plate is analysed. An integral equation is formulated for the equivalent magnetic current and solved by the conventional moment method. Numerical results are presented for the magnetic current, reflection and transmission coefficients, a normalized radiated power in the slit, and equivalent circuit parameters. The equivalent circuit parameters are an useful quantities in the study of the E-plane coupled microstrip antennas.

• 한국유체기계학회 논문집
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• 제17권3호
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• pp.65-70
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• 2014

The effectiveness of a perforated plate installed additionally at butterfly valve to reduce cavitation which can cause vibration, noise, erosion, and flow path blockage has been investigated using CFD. Rayleigh-Plesset equation was applied to simulate cavitation phenomena. 3D flow simulations have been performed for 6 cases to consider the occurrence of cavitation at the downstream of the valve. From the present results, the perforated plate was thought to be very effective to suppress the cavitation inside of the pipe.

• 대한기계학회논문집B
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• 제25권7호
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• pp.877-884
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• 2001

A theoretical analysis is conducted on the Stokes flow in a narrow channel. A vertical fin is mounted on the bottom plate and the flow is induced by uniformly sliding top plate. The governing harmonic equation was solved in the transformed ζ-plane, which is obtained by applying conformal mappings to the physical plane. By using well-known transformation technique, closed-form expressions for velocity and skin frictional stress on the top and bottom plates were obtained.

• 소음진동
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• 제6권6호
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• pp.781-790
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• 1996

The goal of current research is to suppress the acoustic noise radiated from vibration of composite plate structure. The induced noise can be reduced through the control of the corresponding structural vibration modes by using the piezoelectric materials as actuator. The acoustic fields are to be analyzed through the boundary element method (BEM) based on the Rayleigh intergral equation and structural system through the finite element method (FEM). The suppression of rediated sound is studied by adaping the piezoelectric material as the distributed actuator. Numerical results are presented on the sound radiation from composite plate of arbitrary boundary conditions, the noise reduction adapting the piezoelectric materials as distributed actuator. The results show the effectiveness and possibility of piezoelectric actuator in the control of sound radiation from composite structure.

• 소음진동
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• 제8권5호
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• pp.936-948
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• 1998

A theoretical formulation for the analysis of free vibration of a cylindrical shell with a circular plate attached at an arbitrary axial position of the shell under various kinds of boundary conditions was derived and programed to get the numerical results for natural frequencies and mode shapes of the combined system. The boundary conditions of the shell to be considered here are clamped-free, clamped-simply supported, both ends clamped and both ends simply supported. The frequencies and mode shapes from theoretical calculation were compared with those of commercial finite element code, ANSYS. The results showed good agreement with those of ANSYS in frequencies and mode shapes. The program will contribute to the design optimization of a shell/plate combined system through the analysis of natural frequencies and mode shapes for the system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.357-362
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• 2000

Though there have been many researches to investigate the relationship between the damage location, damage size and the changes in eigenparameters, there have been few studies on the small-sized damages. Thus, this paper considers the plate with small local damages. The equation of motion for damaged plate is derived in terms of the damage distribution function and then the effects of small damages on the dynamic characteristics of plate are investigated. It is observed that the damage-induced modal coupling and a sufficient number of vibration modes should be considered especially for small damage detections.

• 한국소음진동공학회논문집
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• 제26권1호
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• pp.104-109
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• 2016

The noncontact vibration exciter system using the electro-magnet for a thin plate is studied in this paper. Based on the Euler-Bernoulli beam theory, the equation of motion of thin plate is derived. The main purpose of this experiment is to match the input-frequency and response frequency of thin plate. The test equipment is configured to vibrate on both sides of the thin plate using the electro-magnet. Two frequencies(input frequency and response frequency) in our experiments show very good agreement. This study results will contribute to basic investigate of an alternative air-knife system for the steel industry.

• Composites Research
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• 제13권5호
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• pp.37-43
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• 2000

본 연구는 면내 전단력을 받으며 수직보강재가 설치된 직교이방성판의 탄성좌굴거동해석에 관한 것으로서, 판의 네 변은 단순지지 되었다고 가정하였으며, 등간격으로 배치된 보강재는 비틀림강성을 무시한 보요소로 간주하였다. 수직보강된 직교이방성판의 좌굴해석식은 Rayleigh-Ritz법을 사용하여 유도하였다. 유도된 좌굴해석식을 사용하여 수직보강된 직교이방성판의 좌굴응력의 한계값을 구해 그래프로 제시하였으며, 이 결과를 사용하여 수직보강재가 한 개 또는 두 개 설치된 판의 전단좌굴응력이 최대가 되도록 하기 위해 보강재에 요구되는 휨강성을 구하여 그래프로 제시하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.671-675
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• 2000

In this study, an FRF-based structural damage identification method (SDIM) is proposed for plate structures. The present SDIM is derived from the partial differential equation of motion of the damaged plate, in which damage is characterized by damage distribution function. Various factors that might affect the accuracy of the damage identification are investigated. They include the number of modal data used in the analysis and the damage-induced modal coupling. In the present SDIM, an efficient iterative damage self-search method is introduced. The iterative damage search method efficiently reduces the size of problem by searching out and then by removing all damage-free zones at each iteration of damage identification analysis. The feasibility of the present SDIM is studied by some numerically simulated tests.