• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.240-245
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• 2016

In this paper, stress contour plots depending on length, load, and diameter of the implant are presented. Depending on the condition and amount of cortical bone, process of implanting can be difficult and stress becomes important. Therefore deciding the right length and diameter of implant is critical. When analyzing stress in the implant, Von-mises yield criterion is often used; however, due to hardship of acquiring the actual material property of surrounding bones, simplified model of a implant was adapted in finite element analysis program of EDISON. The result acquired from EDISON program was then compared with results of different research papers.

• 한국정밀공학회지
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• 제18권1호
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• pp.201-212
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• 2001

If defects are located far apart, fatigue cracks are independently initiated from them and gradually approach other cracks so that the fatigue life becomes influenced by the crack growth behavior of those interacting cracks. In this study, the effect of the stress interaction between defects on the fatigue crack propagation behavior is investigated experimentally and these results are verified by finite element method. In addition, fatigue crack propagation behaviors under micro hole interaction field are studied.

• 반도체디스플레이기술학회지
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• 제16권4호
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• pp.68-74
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• 2017

Nanoimprint lithography (NIL) is a next generation technology for fabrication of micrometer and nanometer scale patterns. There have been considerable attentions on NIL due to its potential abilities that enable cost-effective and high-throughput nanofabrication to the display device and semiconductor industry. Up to now there have been a lot of researches on thermal NIL, but most of them have been focused on polymer deformation in the molding process and there are very few studies on the cooling and demolding process. In this paper a cooling process of the polymer resist in thermal NIL is analyzed with finite element method. The modeling of cooling process for mold, polymer resist and substrate is developed. And the cooling process is numerically investigated with the effects of imprinting temperature and residual layer thickness of polymer resist on stress distribution of the polymer resist. The results show that the lower imprinting temperature, the higher the maximum von Mises stress and that the thicker the residual layer, the greater maximum von Mises stress.

• Communications for Statistical Applications and Methods
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• 제29권1호
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• pp.1-25
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• 2022

A modified Bagdonavičius-Nikulin chi-square goodness-of-fit is defined and studied. The lymphoma data is analyzed using the modified goodness-of-fit test statistic. Different non-Bayesian estimation methods under complete samples schemes are considered, discussed and compared such as the maximum likelihood least square estimation method, the Cramer-von Mises estimation method, the weighted least square estimation method, the left tail-Anderson Darling estimation method and the right tail Anderson Darling estimation method. Numerical simulation studies are performed for comparing these estimation methods. The potentiality of the new model is illustrated using three real data sets and compared with many other well-known generalizations.

• Structural Engineering and Mechanics
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• 제88권6호
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• pp.609-623
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• 2023

The objective of this study is to investigate the distribution of von Mises stress, peeling stress, and shear stress in the adhesive layer used to bond two composite panels, considering various parameters using a three-dimensional finite element method. The stiffness of the materials and the effect of the stacking order on the amount of load transferred to the adhesive layer were examined to determine which type of laminate generates less stress at the bond line. The study analyzed six different stacking sequences, all with a common first layer in contact with the adhesive and a 0° orientation. Additionally, the impact of using hybrid composites on reducing bond line stress was investigated.

• 치과방사선
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• 제22권1호
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• pp.7-22
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• 1992

The stress distributions on a human mandible for 18 load cases under two different boundary conditions (mouth open and closed), using the three dimensional finite element modeling were studied. Also, the expected fracture loads for each load cases were calculated by using the Von-Mises yield criterion. The model of a mandible with all teeth was composed of 2402 hexahedron elements and 3698 nodes. CAD techniques were used to analyze the 3-dimensional results. The conclusions of this study were as follows: 1. In the mouth open state, the maximum stress occured at the condyle neck; when the lateral load was exerted, the maximum stress occured at the load side condyle. 2. In the mouth closed state, when the loads were exerted on the mandibular body and chin, the maximum stress occured at the loaded area, and when the loads were exerted on the angle and ramus, the maximum stress occured at the condyle neck. 3. The expected fracture loads in each load case were calculated using the Von-Mises yield criterion, and it was confirmed that the mandible in the mouth open state was more easily fractured than that in the mouth closed state, and the expected fracture loads are lesser in the cases that load direction is parallel at mandibular plane than 45°. 4. The magnitudes of the expected fracture loads increased in the order of angle, ramus, body and chin in case of the mouth closed state, while chin, body, angle and ramus in case of the mouth open state. 5. The Von-Mises stress concentration regions analyzed by F.E.M. corresponded well with the results of clinical studies.

• 마이크로전자및패키징학회지
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• 제27권1호
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• pp.67-73
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• 2020

본 논문에서는 FEM(유한요소) 기법을 사용하여 FCCSP용 임베디드 PCB의 캐비티 구조와 프리프레그 재료의 종류에 따라 PCB에서 발생한 warpage와 von Mises 응력 해석을 수행하였다. 유한요소 해석에는 1/2 substrate 모델과 정적해석이 적용되었다. warpage 해석 결과에 의하면 칩이 실장되는 캐비티와 칩의 간격이 증가할수록 warpage가 증가하였고, 탄성계수와 열팽창계수가 높은 프리프레그 재료를 적용했을 때 warpage가 증가하였다. 응력의 해석결과에 따르면 칩이 실장되는 캐비티와 칩의 간격의 영향은 프리프레그 재료에 따라 다르게 나타났다. 즉 열팽창계수가 코어재료보다 월등히 높은 재료를 적용했을 때 칩이 실장되는 캐비티와 칩의 간격이 증가할수록 응력이 증가하였고, 열팽창계수가 코어재료보다 낮은 프리프레그를 적용하면 응력이 감소하였다. 이와 같은 결과는 신뢰성 관점에서 실장된 칩이 실장되는 캐비티의 구조와 프리프레그 재료간 상관관계가 있음을 시사하고 있다.

• 대한치과교정학회지
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• 제46권4호
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• pp.189-198
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• 2016

Objective: The purpose of this study was to analyze stress distributions in the roots, periodontal ligaments (PDLs), and bones around cylindrical and tapered miniscrews inserted at different angles using a finite element analysis. Methods: We created a three-dimensional (3D) maxilla model of a dentition with extracted first premolars and used 2 types of miniscrews (tapered and cylindrical) with 1.45-mm diameters and 8-mm lengths. The miniscrews were inserted at $30^{\circ}$, $60^{\circ}$, and $90^{\circ}$ angles with respect to the bone surface. A simulated horizontal orthodontic force of 2 N was applied to the miniscrew heads. Then, the stress distributions, magnitudes during miniscrew placement, and force applications were analyzed with a 3D finite element analysis. Results: Stresses were primarily absorbed by cortical bone. Moreover, very little stress was transmitted to the roots, PDLs, and cancellous bone. During cylindrical miniscrew insertion, the maximum von Mises stress increased as insertion angle decreased. Tapered miniscrews exhibited greater maximum von Mises stress than cylindrical miniscrews. During force application, maximum von Mises stresses increased in both groups as insertion angles decreased. Conclusions: For both cylindrical and tapered miniscrew designs, placement as perpendicular to the bone surface as possible is recommended to reduce stress in the surrounding bone.

• 한국지반공학회논문집
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• 제15권6호
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• pp.121-130
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• 1999

본 연구는 전응력 개념에 근거한 비등방경화 구성관계를 적용하여 유한요소해석을 수행하는 데 목적이 있다. 이에 대상문제에 적합한 비등방경화 구성관계를 개발하여 수학적으로 정식화하고 실험적으로 검증하였다. 동반논문에서는 유한요소해법의 정확도와 수렴성을 확보하도록 정식화하여 해석코드에 구현한 후 실제문제를 해석한다. 제안된 구성관계는 von Mises 형태의 파괴규준과 일반 등방경화규칙에 의거한 비등방경화규칙을 채택하여 비선형성과 비등방성이 심한 응력-변형률 관계를 모델하였다. 결과적으로 UU 삼축시험, 과압밀 상태에 대한 CU 삼축시험, $K_0$ 압밀조건의 주응력축 회전시 비등방적 거동에 대하여 검증할 수 있었다.

• 한국가스학회지
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• 제10권4호
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• pp.23-28
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• 2006

본 연구에서는 LPG 용기용 가스밸브의 강도 안전성과 몸체의 경량화 해석을 9개의 밸브모델에 대하여 유한요소해석 프로그램 MARC 및 다구찌의 실험적 설계법을 사용하였다. 가스밸브의 몸체에 작용하는 Von Mises 최대응력은 밸브에 작용하는 최대가스압력 $91kg/cm^2$을 적용하여 황동밸브 구조물의 안전성을 고찰하였다. 여기서 최대압력 $91kg/cm^2$은 LPG 가스용기의 안전계수를 고려한 것으로 안전성 해석이나 최적설계를 수행하는데 충분한 작동압력이다. 밸브몸체의 자중량을 줄이기 위해 수행된 해석은 LPG가스의 유동손실을 줄이고, 최적설계에 따라 소재가격을 낮출 수 있기 때문에 설계단계에서 고려해야 할 하나의 주요변수이다. 계산결과에 따르면, 최적설계 밸브모델은 9번이고, 이때의 최적설계 변수는 가스가 통과하는 밸브의 아래쪽 A의 반경 r=10mm, 위쪽 B의 반경 r=6mm, A와 B의 연결부 파이프 길이 l=2 mm로 결정되었다.