• Journal of Advanced Marine Engineering and Technology
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• 제14권4호
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• pp.46-56
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• 1990

Stress analysis of axi-symetric body with non-symetric loading and non-symetric given displacements is investigated in this paper using the finite element method. As the non-symetric load and non-symetric given displacements of axi-symetric body are generally periodic functions of angle .theta., the nodal forces and nodal displacements can be expanded in cosine and sine series, that is, Fourier series. Furthermore, using Euler's formula, the cosine and sine series can be converted into exponential series and it is prooved that the related calculus become more clear. Substituting the nodal displacements expanded in Fourier series into the strain components of cylindrical coordinates system, the element strains are expressed in series form and by the principal of virtual work, the element stiffness martix and element load vector are obtained for each order. It is also showed that if the non-symetric loads are even or odd functions of angle ${\theta}$ the stiffness matrix and load vector of the system are composed with only real numbers and relatively small capacity fo computer memory is enough for calculation.

• Interaction and multiscale mechanics
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• 제2권4호
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• pp.413-430
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• 2009

The stator tooth is a key component of the electromechanical integrated toroidal drive system. The stator tooth is spiral in shape and the calculation of its displacements is difficult. In this paper, using the coordinate transformation method, the displacements of the stator tooth in the local coordinate system are expressed as the function of the variable in the drive coordinate system. Using the minimum potential energy principle, the equations of the displacements of the stator tooth under the loads are deduced. The displacement distributions within the stator tooth are investigated and the changes of the displacement distributions along with the main parameters are analyzed. This research can offer the basis for the strength and stiffness design of the drive system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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• pp.147-155
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• 2001

A data acquisition and signal processing system for evaluating the current collection system is developed, and subsequently applied to the measurement and analysis of the contact force in the current collection system of the proposed Korean High Speed Railway. The measurement of the contact force is based on an algorithm that employs the relationship between the contact force, the strain due to the bending moment and the panhead inertia. For the contact forces in the frequency range of less that 50Hz, the panhead can the modeled as a rigid body in the inertia calculation. For higher frequencies however, the bending vibration modes of the panhead need to be accounted for as well.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.225-228
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• 2001

A new three-dimensional thin shell element for the structure containing an integrated distributed piezoelectric sensor and actuator is proposed. A finite element formulation for the static response of the shell with piezoelectric sensor／actuator is derived. The assumed strain formulation and the bubble function improves the performance of the shell element. The verification through the calculation of the static response for the piezoelectic bimorph beam shows that the results agree with those from the theoretical analysis very well.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 춘계학술대회논문집
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• pp.98-105
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• 1997

The behaviour of alloys in the semi-solid state strongly depends on the imposed stress state and on the morphology of the phase which can very from dendritic to globular. The estimation of behaviour characteristic in the compression simulation with seim-solid materials are calculated by finite element method with proposed algorithm. The proposed theoretical model and a various boundary conditions for compression process is investigated with the coupling calculation between the liquid phase flow and the solid phase deformation. The simulation process considering soldification phenomena is performed to the isothermal conditions of two dimensional problems. To analysis of compression process by using semi-solid materials, a new stress-strain relationship is described, and compression analysis is performed by viscoelastic model for the solid phase and the Darcy's law for the liquid flow. The calculated results for compression force and ram displacement will be compared to experimental data.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.201-204
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• 2006

A three-dimensional finite element (FEM) model has been developed to simulate the deformation due to bead on plate welding of curved plates with curvature in the weld direction. By using traditional method such as thermal-elastic-plastic FEM, the weld-induced deformation can be predicted accurately. However, this method is not practical approach to analyze the deformation of large and complex structures such as ship hull structures in view of time and cost. This study is classified from the aspect of equivalent load based on inherent strain near the weld line. Therefore, the residual deformation can be simply computed by elastic analysis. Further more, a practical solution is proposed to consider the contact between the plate and the positioning jig by judging the reaction forces of the jig at calculation step and the effect of the longitudinal curvature is closely considered.

• 한국해양공학회지
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• 제23권1호
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• pp.146-151
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• 2009

In this paper, a weight function theory for the calculation of the mode III stress intensity factor in a rectilinear anisotropic body is formulated. This formulation employs Lekhnitskii's formalism for two dimensional anisotropic materials. To illustrate the method used for the weight function theory, we calculated the mode III stress intensity factor in a single edge-notched configuration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1920-1922
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• 1996

After determining the type and string condition of conductor of 765kV transmission lines, we studied the mechanical strength system of insulator strings to support conductors and insulate conductors from towers. In this paper, for the insulator strings which will be used in 765kV transmission lines, we're going to optimally determine the mechanical strength system and supporting method in the consideration of the reliability, economics and the survey data of T/L routes, and also suggest the calculation method to stipulate for the application limits of suspension and strain insulator strings according to the loadspan and height difference of tower.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.165-169
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• 2000

A simple method was suggested to calculate the stress intensity factor for a one-sided patched crack with finite thickness. To consider out-of-plane bending effect resulting from the load-path eccentricity, the spring constant as a function of the through-thickness coordinate z was calculated from the stress distribution in the un-cracked plate, ${\sigma}_{yy}(y=0,\;z)$, and the displacement for the representative single strip Joint, $u_y(y=0,\;z)$. The stress Intensity factors were obtained using Rose's asymptotic solution approach and compared with the finite element results. In short crack region, two results had a little difference. However, two results were almost same in long crack region. On the other hand, the stress intensity factor using plane stress assumption was more similar to finite element result than plane strain condition.

• 대한기계학회논문집A
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• 제36권2호
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• pp.149-156
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• 2012

파괴역학에서 가중함수는 응력확대계수를 계산하기 위하여 사용되어진다. 본 논문에서는 균열을 가진 횡등방성 압전재료에 대한 전기-기계적 분석을 행하여 평면변형률 상태의 압전문제를 Leknitskii 해석법으로 풀었고 가중함수이론을 압전재료에 확대 적용하였다. 가중함수이론을 이용하여 응력확대계수와 전기변위확대계수를 구하였다.