• 한국자동차공학회논문집
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• 제23권2호
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• pp.208-213
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• 2015

In this study, two models due to the configuration of caliper cylinder among the parts of automotive brake system are studied by structural and fatigue analysis. As the maximum equivalent stress at model 2 becomes 1.5 times lower than model 1, model 2 can endure load higher than model 1. In case of fatigue damage analysis on model 1 and 2, model 1 has the damage area more than model 2. Fatigue damage at model 1 happen more than model 2. These study results can be effectively utilized with the design on caliper cylinder by anticipating prevention against its damage and investigating durability.

• 한국기계가공학회지
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• 제15권1호
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• pp.42-49
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• 2016

This study was analyed V-bending in order to analyze the spring-back phenomenon in the roll forming process. The material of forming sheet used in the roll forming process is high tension steel and the product name of sheet material is POSTEN 60. The most important variable is the number of roll passes (3-Pass, 4-Pass, 5-Pass, 6-Pass and 10-Pass) and other roll forming process variables were fixed. To determine the characteristics of the tension and compression, the forming sheet was analyzed by dividing the layer (Upper and Bottom) in the thickness direction from the center line. The results of FEM simulation analysis was derived to von-mises stress equivalent strain, and the spring-back value was calculated according to the final forming shape. The more number of the roll pass, von-mises stress and equivalent strain value of forming sheet were lowed. Also, spring-back values tended to decrease. The results of this study can be utilized for prediction and trend of spring-back value in the roll forming process applied to high tension steel sheet. So, development time and cost of the roll forming process is expected to be reduced.

• 한국가스학회지
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• 제15권1호
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• pp.35-39
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• 2011

본 논문에서는 FEV 차량용 복합소재 연료탱크의 탄소섬유 적층두께에 따라 달라지는 강도안전성에 미치는 기여율의 영향을 해석하고자 한다. 기여율에 의한 영향을 FEM 모델링으로 고찰하기 위해, 복합소재 연료탱크의 알루미늄 라이너와 탄소섬유 적층에 작용하는 von Mises 등가응력을 후프방향과 헤리컬방향에 대하여 각각 계산 하였다. FEM 해석결과에 따르면, 알루미늄 라이너에 작용하는 등가응력 기여율은 후프방향으로는 77.5%, $70^{\circ}C$ 경사진 헤리컬방향으로는 18.11%, $12^{\circ}C$ 경사진 헤리컬방향으로는 4.39%로 각각 작용하는 것으로 나타났다. $12^{\circ}C$ 경사진 탄소섬유의 적층 두께비가 후프방향 적층 두께비의 42% 정도로 높게 유지됨에도 불구하고 알루미늄 라이너 소재에서 보여준 기여율 경향은 탄소섬유 적층의 강도안전성에 대해서도 유사한 것으로 나타났다. 결과적으로, 탄소섬유 연료탱크의 강도안전성은 탄소섬유 적층의 두께보다 와인딩 각도에 의해 더 많은 영향을 받는다는 계산결과를 보여주고 있다.

• 대한토목학회논문집
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• 제11권1호
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• pp.69-78
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• 1991

본 연구은 단조하중을 받는 철근콘크리트 휨부재의 처짐을 해석하기 위한 것으로서, 콘크리트는 직교이방성재료로 모형화하고, 이력거동과 균열거동을 추적하기 위하여 등가일축변형율과 균열변형율을 이용하며, 철근은 탄소성재료로 모형화하고, 항복조건으로는 von Mises기준을 적용한다. 단조하중을 받는 철근콘크리트 휨부재의 변위거동을 해석하기 위하여 4절점 등매개요소와 트러스요소의 유한요소정식과 중분-반복기법을 적용한 유한요소 프로그램을 도출하고, 단조하중을 받는 과소 철근콘크리트 보에 대한 실험결과와 본 연구의 해석결과를 비교하여 개발된 모형과 해석프로그램의 타당성을 검증한다.

• 마이크로전자및패키징학회지
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• 제18권2호
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• pp.29-33
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• 2011

솔더와 PCB Cu 패드와 솔더 경계면에서 발생하는 수직응력과 수평응력을 분석하여 PGA 패키지의 신뢰성 향상을 위한 리드핀의 형상설계에 대한 연구를 수행하였다. 이와 같은 연구를 위해 리드핀의 $20^{\circ}$ 각도 굽힘 변형과 50 ${\mu}m$ 인장조건에서 4인자 3수준의 다구찌 최적설계와 유한요소해석을 수행하였다. 해석결과에 의하면 리드핀의 헤드곡면과 PCB Cu 패드가 접촉하는 폭(d2)이 솔더에서 발생하는 응력감소에 가장 큰 영향을 미치는 인자로 계산되었다. 또한, 다 구찌법의 파라메타 설계에 의해 기존 리드핀 형상모델에 비해 약 18.7%의 등가 von Mises 응력이 감소하는 형상을 도출하였다. 한편, 최대 수직응력이 발생하는 위치가 PCB의 Cu 패드와 솔더의 외곽이 접촉하는 위치이고 최대 수평응력이 발생하는 위치가 SR 층과 솔더의 외곽표면이 접촉하는 위치임을 파악하여, PGA 패키지의 박리 불량은 솔더의 외곽부터 발생하여 내부로 진행될 것으로 예측되었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권3호
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• pp.175-180
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• 2004

In this study, three treatment options to replace two posterior missing teeth were investigated using three dimensional finite element analysis: two wide(${\phi}5.0mm$) implants(the experimental model I), two standard(${\phi}3.75mm$) implants(the experimental model II), and three standard(${\phi}3.75mm$) implants(the experimental model III). Two kinds of load case were applied ; 1) perpendicular on occlusal surface(axial load), parallel on occlusal surface(lateral load). 2) perpendicular on occlusal surface(3mm lateral to central point). The results obtained from this study were as follows; value of Von-mises stress (equivalent stress) was smallest in the two wide implant among the three experimental models. It was reported that the diameter is the efficient factor than osseointegrated surface area.

• 한국생산제조학회지
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• 제21권5호
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• pp.747-754
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• 2012

A solar power generator is usually installed outdoors and it is exposed to extreme environments such as snow weight and wind loading. The solar tracker structure should be designed to have sufficient stiffness and strength against such loads. In this paper, simulations are performed by varying the parameters such as wind directions, wind speeds and the pose of the solar panel to evaluate the effects of extreme wind on solar tracker. As the effects of wind load, maximum displacement and maximum equivalent stress in the solar tracker are calculated. Finite element stress analysis is carried out by using the pressure distribution that is obtained by prior wind load analysis due to the flow around the solar tracker. The stress analysis of solar tracker to check and/or improve structural robustness provides some useful instructions for structural design or revision of solar tracker.

• 한국생산제조학회지
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• 제21권1호
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• pp.21-25
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• 2012

In this study, the safest model can be selected by the simulation result of structural safety analysis according to the shape of impact bar affected at side door of automobile. The open sectional model of semicircle type has the lowest deformation and stress among 4 kinds of models. As the weight of this model has 30% in comparison with other models, it becomes most economical and stable. As the open sectional model of cap type the highest deformation and stress among 4 kinds of models, it becomes weakest. The closed models with circular and rectangular types has the stress far lower than cap type. The maximum deformation is shown at the center part of impact bar but the maximum stress occurs at the joint part between impact bar and frame.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.549-567
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• 1994

Restoration of severly damaged teeth after endodontic treatment had been an interest to many dentists, and it is a fact that there have been lots of studies about it. In these days, although we have used Para-Post, pins, threaded steel post, cast gold post and core, and so on, as a method of restoration frequently, it has been in controversy with the influence of them on the teeth and surrounding periodontal tissue. In this study, we assume that the crown of the upper incisor have severly damaged, so, after the root canal therapy, 4 types of restoration had been carried out; 1) coronal-radicular amalgam restoration, 2) after setting up the Para-Post, restore with composite resin core only, 3) after setting up the Para-Post; restore with amalgam core, then cover with the PPM crown 4) after setting up the Para-Post, restore with composite core, then cover with the PPM crown. After restoration, in order to observe the concentration of stress at internal portion of the teeth and the sourrounding periodontal tissue, developing a 2-dimensional finite element model of labiopalatal section, then loading forces from 3 direction - direction of 45 degrees from lingual side near the incisal edge, horizontal direction from labial height of contour, vertical direction at the incisal edge-were applied. The analyzed results were as follows: 1. Stress of the normal central incisor was concentrated on the dentin aroundpulp chamber, labiocervical portion of a tooth and root apex, but with the alveolar bone, in the case of load from the direction of 45 degrees from lingual side near the incisal edge showed remarkable concentration of stress: 2. Coronal-radicular amalgam technique -showed less concentration of stress on the root and surrounding periodontal tissue than the restoration with the Para-Post. 3. The von Mises equivalent stress on the Para-Post showed maximum value at root-core junction rather than both ends and model with PPM restoration with amalgam core showed the least concentration of stress. Only the force from horizontal direction showed large shear stress on internal portion of the root, root apex and alveolar bone. 4. PPM crown with composite core rarely showed the concentration of stress on root and periodontal tissue. 5. As for alveolar bone, remarkable shear stress was concentrated on labial and palatal side by horizontal load.

• Wind and Structures
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• 제36권1호
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• pp.31-40
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• 2023

This paper investigates the mechanical behavior of full-scale offshore fish cages under hydrodynamic loads. To simulate different cases, different materials were used in the fish cage and analyzed under different flow velocities. The cage system is studied in two parts: net cage and floating collar. Analyses were performed with the ANSYS Workbench program, which allows the Finite Element Method (FEM) and Computational Fluid Dynamics (CFD) method to be used together. Firstly, the fish cage was designed, and adjusted for FSI: Fluid (Fluent) analysis. Secondly, mesh structures were created, and hydrodynamic loads acting on the cage elements were calculated. Finally, the hydrodynamic loads were transferred to the mechanical model and applied as a pressure on the geometry. In this study, the equivalent (von Mises) stress, equivalent strain, and total deformation values of cage elements under hydrodynamic loads were investigated. The data obtained from the analyses were presented as figures and tables. As a result, it has been shown that it is appropriate to use all the materials examined for the net cage and the floating collar.