• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1992.10a
• /
• pp.124-129
• /
• 1992

이동 집중력 및 집중질량에 의한 이동하중을 받는 직사각형 보강판에 대하 여 보강재효과집중 모델링방법에 의거하여 보강판을 등방성 박판 및 보강재 효과를 반영한 등가보요소로 이루어진 판-보 조합체로 유한요소 모델링하고 Newmark의 직접 시간적분법을 이용한 동응답 해석방법을 정식화하였다. 일 련의 수치계산 예를 통하여 본 연구에서 제시한 방법이 이동하중을 받는 보 강판의 동응답 해석문제에 효과적으로 적용될 수 있음을 확인하였다. 아울러 parametric study를 통하여 이동하중이 작용하는 보강판의 동응답특성은 이 동하중의 질량효과를 고려하는 경우와 고려하지 않는 경우 매우 달라지며, 이동하중에 의한 동적응답은 이동속도가 증가할수록 정하중에 의한 응답보 다 증폭되어 나타나고 증폭비율이 질량효과를 고려할 경우 훨씬 더 커짐을 확인하였다.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.29 no.1
• /
• pp.37-44
• /
• 2016

This study is concerned with the numerical investigation of dynamic characteristics of 2.5MW-class wind turbine gearbox in which the misalignment improvement of plenary gear shafts by the flexible pins and the dynamic impact response are analyzed by the finite element method. The tooth contact between gears is modelled using the line element having the equivalent tooth stiffness and the contact ratio to accurately and effectively reflect the load transmission in the internal complex gear system. The equivalent tooth stiffness is calculated by utilizing the tooth deformation analysis and the impulse torque is applied to the input shaft for the dynamics response characteristic analysis. Through the numerical experiments, the equivalent tooth stiffness model was validated and the misalignment improvement of planetary gear shafts was confirmed from the comparison with the cases of fixed shafts at one and both ends.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.16 no.1
• /
• pp.77-86
• /
• 2003

Dynamic response of baffled fuel-storage tank in turnaround motion is simulated using the ALE finite element method. Fuel-storage tank undergoes abrupt impact load caused by inertia force of internal fuel in turnaround motion. Also, large dynamic force and moment caused by this load influence structural stability and control system. In this paper, ring-type baffles are adopted to suppress the dynamic influence. Through the parametric analysis with respect to the baffle number and location, the effects of baffle on the dynamic response of baffled fuel-storage tank is analyzed. The ALE finite element method is adopted for the accurate and effective simulation of the hydrodynamic interaction between fluid and structure.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.23 no.5
• /
• pp.493-499
• /
• 2010

In the sea-floating logistics port called mobile harbor a crane system with the different structure from the conventional above-ground container crane is installed. And, the dynamic stability of whole mobile harbor by the wave excitation is definitely affected by the crane positioned at the top. This paper is concerned with the dynamic rolling analysis of the mobile harbor subject to sea state 3 wave excitation, for which two-step analysis procedure composed of theoretical and numerical approaches is employed. First, the rigid rolling of mobile harbor is obtained according to the linear wave theory. And then, the dynamic rolling response of the flexible crane system caused by the rolling excitation of mobile harbor is analyzed by finite element analysis. The coupled interaction effect between the sea wave and the mobile harbor is taken into consideration by the added mass technique.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.29 no.1
• /
• pp.285-290
• /
• 2005

Until now, korean aquaculture industry has been grown largely from a quantitative viewpoint. However, an increase of quantity has caused lots of problems producing a derived effect recently. Nearly 82% of korean aquaculture farms had been installed mainly at inshore of the southern sea and also sewage, factory wastes, high density of fishcage at the limited area and autoinfection have deteriorated inshore fisheries. The offshore have been on the rise for the solution to these problems since it has clear seawater reduces the environmental pollution with much current. As a matter of fact, the existing inshore fishcage facilities have trouble advancing to the offshore due to the rough environmental conditons such as a high sea, strong currents etc.; therefore, it is necessary to develop a new cultivating equipment fit the open sea conditons. In this research, the theoretical study and experimental analysis have been carried out for the fishcage design of the structure which is able to use at the open sea.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.4 no.1
• /
• pp.89-98
• /
• 2000

본 연구에서는 비비례 감쇠시스템을 효율적으로 해석할 수 있도록 모드 가속도법(mode acceleration method)과 모드 절삭 보강법(modal truncation augmentation method)을 확장하고 그 사용성을 검증하였다,. 비례 감쇠시스템의 동응답해서에 널리 사용되는 모드 가속도법과 모드 절삭보강법은 누락된 고차모드의 영향을 보정하여 모드 중첩법의 결과를 개선하는 방법이다. 기존의 방법들로 비비례 감쇠시스템을 해석하는 경우 비비례 감쇠특성을 무시하지 않으며 정확하고 효율적으로 해석할 수 있도록 모드 가속도법과 모드 절삭보강법을 확장하였다. 비례 감쇠시스템에서는 모드 가속도법보다 모드 절삭보강법이 더 효율적인 반면에 비비례 감쇠시스템에서는 대부분의 경우에 있어서 확장된 두 방법의 효율성이 동일하다. 그러나 수치적 안정성은 확장된 모드 가속도법이 모드절삭 보강법보다 우수하다. 이와 같은 확장된 모드 가속도법과 모드 절삭보강법의 사용성 검？을 위해서 이론적 방법과 수치예제를 수행하였다.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.16 no.1
• /
• pp.33-42
• /
• 2003

This paper deals with the FEM analysis of nonlinear sloshing of incompressible, invicid and irrotational flow in two dimensional rectangular tank. We use laplace equation based on potential theory as governing equation. For large amplitude sloshing motion, kinematic and dynamic free surface conditions derived from Bernoulli equation are applied. This problem is solved by FEM using 9-node elements. For the time integration and accurate velocity calculation, we introduce predictor-corrector time marching scheme and least square method. Also, numerical stability in tracking of free surface is obtained by direct calculation of free surface location to time variation. Numerical results of sloshing induced by harmonic excitations, while comparing with those of linear theory and references, prove the accuracy and stability. After verification of our program, we analyze sloshing response characteristics to the fluid height and the excitation amplitude.