• 한국기계가공학회지
• /
• 제11권6호
• /
• pp.1-8
• /
• 2012

This study investigates stress and deformation due to static and dynamic vibration analysis about various types of bike handles installed with smart phone depositories. When force is applied on the side of handle at the models of type 1, 2, 3 and 4, the maximum equivalent stress is highest at type 2. The stress or deformation becomes lowest among these 4 model types. At vibration analysis, type 1 becomes safest within the range of 500Hz and type 3 becomes stable within the range of 100Hz. The result of this study can be applied with the design of bike handle installed with smart phone depository. The damage or deformation due to vibration can be prevented when the bike falls down. This result can be widely utilized to investigate and predict the durability.

• 한국항공우주학회지
• /
• 제30권6호
• /
• pp.84-91
• /
• 2002

본 연구에서는 열전달 해석을 통하여 발전용 터빈 블레이드의 온도 분포를 계산하였고, 열하중과 원심력에 의한 선형응역 해석을 수행하였다. 정상상태 열전달 해석 결과, 블레이드의 앞전과 끝단에서 높은 온도 분포가 나타났으며 열응력은 다른 부분에 비해 압력면 부분에서 높게 나타났다. 온도의 영향을 고려하지 않은 원심응력 해석에는 fir tree 앞전 부분에서 가장 높은 등가 응력이 나타났다. 온도와 원심력을 모두 고려한 해석 결과에서도 최대 등가 응력은 fir tree부분에서 발생하였다. 열하중과 원심력에 대한 선형응력 해석 결과 GTD111 터빈 블레이드는 항복응력에 도달하지 않아 안전하다.

• 한국융합학회논문지
• /
• 제7권1호
• /
• pp.161-166
• /
• 2016

본 연구에서는 타이로드 엔드의 형상에 따른 변형량과 응력, 피로 수명을 연구하였으며, 총 세 가지 형상을 가진 타이로드 엔드들을 CATIA 프로그램으로 3차원으로 모델링 한 뒤, ANSYS 유한요소해석 프로그램으로 시뮬레이션 해석을 수행하였다. 타이로드 엔드 모델의 형상별로는 모델 A, B 및 C가 있다. 본 연구 결과로서는 모델 A형의 최대 변형량, 최대 등가 응력 및 최대 피로수명들은 각각 0.0614mm, 160.27MPa 및 336,930cycle로 나타났으며, 모델 B형의 최대 변형량, 최대 등가 응력 및 최대 피로수명들은 각각 0.0648mm, 90.889MPa 및 1,171,000cycle로 나타났다. 또한 모델 C형의 최대 변형량, 최대 등가 응력 및 최대 피로수명들은 각각 0.0402mm, 84.794MPa 및 20,000,000cycle로 나타났다. 이러한 결과 값들을 통하여 형상에 따른 타이로드 엔드 모델들의 내구성을 예측할 수 있었고, 보다 진보된 타이로드 엔드의 설계 및 개발을 위한 데이터를 확보할 수 있었다. 또한 디자인 면에서 융합 기술로의 접목도 가능하여 미적인 감각물로 나타낼 수 있다.

• 한국기계가공학회지
• /
• 제10권5호
• /
• pp.65-71
• /
• 2011

This study analyzes about front axle through the analyses of stress, fatigue and vibration. Maximum equivalent stress is shown with the frequency of 60Hz in case of the harmonic vibration analysis applied with force. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of 0 to $-2{\times}10^5MPa$ and the amplitude stress of 0 to $-2{\times}10^5MPa$, the possibility of maximum damage becomes 3%. This stress state can be shown with 6 times more than the damage possibility of 'SAE Bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design of front axle by investigating prevention and durability against its damage.

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

• 한국생산제조학회지
• /
• 제20권3호
• /
• pp.239-244
• /
• 2011

This study analyzes the behaviors on stress, fatigue and vibration about bulldozer in operation. Maximum equivalent stress is shown with the frequency of 100 Hz in case of the harmonic vibration analysis applied with force. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of 0 to -105MPa and the amplitude stress of 0 to $1.617{\times}105MPa$, the possibility of maximum damage becomes 3.23%. This stress state can be shown with 5 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design of bulldozer by investigating prevention and durability against its damage.

• 한국정밀공학회지
• /
• 제21권6호
• /
• pp.131-138
• /
• 2004

The objective of this paper is to decide optimal location of a pin-hole to minimize stress concentration around the hole in a rotating disc. The focus of this investigation is to evaluate the effect of pin-hole on stress distribution around the hole using optimum design technique and finite element analysis. Design variables are the radial and the angular location of pin-hole from center of the hole and objective function is the maximum stress around hole in a rotating disc. Using first order method of optimization technique, we found that the maximum equivalent stress around the hole with optimized pin-hole could be reduced by 15.1% compared to that without pin-hole.

• Restorative Dentistry and Endodontics
• /
• 제23권1호
• /
• pp.163-174
• /
• 1998

The purpose of this study is to evaluate the distribution of stress in the root end resected teeth. The finite element method was used to compare stresses along the root and retrograde filling material in seven two-dimensional models of mandibular 2nd premolar. Each model was endodontic treatment and gold crown' restoration. Each model divided with amagam core restoration or gold casting post restoration. Thus each model divided with shape of root end resection, depth of retropreparation and exposure length of root in the bony cavity. The seven models were classified as in the table 1 below. A load of 500N was applied $45^{\circ}$ diagonally on the lingual slope of the buccal cusp. These mode were analyzed with two dimensional finite element methods. The results of this study were as follows : 1. The maximum tensile stress along the inner canal wall was shown on the model 7. 2. When the model 1 was compared with the model 5, the maximum tensile stress along the inner canal wall showed the model 1. 3. Less equivalent stress was shown on the model 6 and more equivalent stress was shown on the model 4. 4. More shear stress was shown on the retrograde filling material of the model 7. 5. The models with increased length of exposed root in the bony cavity demonstrated a gradual increase to the tensile stress in X direction which occurred approximately a boundary between the bone and exposed root in' the bony cavity. 6. The model which had a case of matching the apex of post and a boundary between the bone and exposed root in the bony cavity demonstrated more increase tensile stress in X direction than other models.

• 한국기계가공학회지
• /
• 제13권1호
• /
• pp.8-15
• /
• 2014

This study investigates structural and vibration analyses for three types of bike frame fork models. As long as the maximum equivalent stresses of these models are lower than the yield stress, the three models are considered to be safe structurally. Type 3, with a maximum equivalent stress of 169.23 MPa, has the lowest stress among the three models and the strongest strength. Types 1, 2 and 3 have natural frequencies lower than 270 Hz. Type 3, with a critical frequency of 118 Hz, has the best durability under vibration among the three models. In order to decrease the vibration transmitted to a bike rider riding on a rough road, the impact due to vibration can be relieved by selecting a Type 3 model from among the three models. The results of this study can be effectively utilized for the design of a bike frame fork as this allows the anticipation and prevention of damage caused by durability issues.

• 한국융합학회논문지
• /
• 제5권3호
• /
• pp.17-22
• /
• 2014

기계 가공에서 사용되는 엔드밀의 사용 시, 공작물과 엔드밀 사이에 발생되는 응력과 밀링기계의 회전력과 공작물 가공에 사용되는 압력으로 인한 세 가지 엔드밀 모델들의 구조적 변형들을 시뮬레이션 해석에 의해서 연구한다. 이 결과들은 구조 및 피로해석으로 이루어진다. 해석 결과, Model 1이 Model 2나 Model 3보다 덜 변형되는 것을 알 수 있다. 그리고 최대 등가응력은 Model 1이 다른 형상의 모델에 비하여 가장 작은 것을 확인할 수 있으며, 3개의 모델 중 Model 1이 다른 모델에 비하여 더 큰 힘을 견딜 수 있을 것으로 사료된다. 본 연구의 결과를 엔드밀의 설계에 응용한다면, 그 파손 방지 및 내구성을 검토하는데 유용하게 활용될 것으로 사료된다.