• 제목/요약/키워드: plastic analysis

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Pseudo plastic zone analysis of steel frame structures comprising non-compact sections

  • Avery, P.;Mahendran, M.
    • Structural Engineering and Mechanics
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    • 제10권4호
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    • pp.371-392
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    • 2000
  • Application of "advanced analysis" methods suitable for non-linear analysis and design of steel frame structures permits direct and accurate determination of ultimate system strengths, without resort to simplified elastic methods of analysis and semi-empirical specification equations. However, the application of advanced analysis methods has previously been restricted to steel frames comprising only compact sections that are not influenced by the effects of local buckling. A concentrated plasticity method suitable for practical advanced analysis of steel frame structures comprising non-compact sections is presented in this paper. The pseudo plastic zone method implicitly accounts for the effects of gradual cross-sectional yielding, longitudinal spread of plasticity, initial geometric imperfections, residual stresses, and local buckling. The accuracy and precision of the method for the analysis of steel frames comprising non-compact sections is established by comparison with a comprehensive range of analytical benchmark frame solutions. The pseudo plastic zone method is shown to be more accurate and precise than the conventional individual member design methods based on elastic analysis and specification equations.

Development of a Five-Day Basic Microsurgery Simulation Training Course: A Cost Analysis

  • Singh, Masha;Ziolkowski, Natalia;Ramachandran, Savitha;Myers, Simon R.;Ghanem, Ali Mahmoud
    • Archives of Plastic Surgery
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    • 제41권3호
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    • pp.213-217
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    • 2014
  • The widespread use of microsurgery in numerous surgical fields has increased the need for basic microsurgical training outside of the operating room. The traditional start of microsurgical training has been in undertaking a 5-day basic microsurgery course. In an era characterised by financial constraints in academic and healthcare institutions as well as increasing emphasis on patient safety, there has been a shift in microsurgery training to simulation environments. This paper reviews the stepwise framework of microsurgical skill acquisition providing a cost analysis of basic microsurgery courses in order to aid planning and dissemination of microsurgical training worldwide.

성형외과 의원의 웹 방문자 수에 영향을 미치는 웹 사이트 속성 (Influence of Website Attributes on the Visit to Plastic Surgery Websites)

  • 조영빈;안성현
    • Journal of Information Technology Applications and Management
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    • 제14권3호
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    • pp.137-149
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    • 2007
  • Most of hospitals, especially small-scale hospitals, have tried to get customers through the Internet as what companies have done recently. There are various attempts that increase visits to one's web-site in plastic surgery hospitals. However, in plastic surgery, there have been few studies on which an attribute contributes to increase the number of web-site visit. In order to derive the important attributes on the number of visit, we compared functional attributes of 30 high-visit plastic surgery web-sites with those of 30 low-visit web-sites using statistical and data mining methods. For analysis, three methods have conducted including Multiple Discriminant Analysis (statistical method), Decision Trees (data mining method), and Artificial Neural Network (data mining method). Furthermore, results of each method have been evaluated one another. The result of this study shows that a few attributes like 'Simulating cyber plastic surgery program', 'recommendation of information' explain the number of the visitors between high and low visit web-site. The methodology employed in this study provides an efficient way of improving satisfaction of visitors of plastic surgery website.

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특수모멘트골조를 가진 이중골조시스템을 위한 부재소성변형 평가 (Evaluation of Member Plastic Deformation Demands for Dual Systems with Special Moment Frames)

  • 엄태성;김재요
    • 한국지진공학회논문집
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    • 제14권5호
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    • pp.41-51
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    • 2010
  • 안전한 내진설계를 위해서는 부재에 요구되는 소성변형을 평가하여야 한다. 본 연구에서는 복잡한 비선형해석없이 탄성 해석결과에 근거하여 이중골조의 부재소성변형을 평가할 수 있는 빠르고 간편한 방법을 개발하였다. 보, 기둥, 벽체 등의 소성변형은 부재강성, 층간변위비, 모멘트 재분배, 단면치수 및 소성힌지 위치의 함수로 결정된다. 벽체와 보가 모멘트 접합된 경우에는 벽체의 소성변형에 의한 로킹효과를 고려하여 증가된 소성변형을 구한다. 8층 이중골조에 대하여 제안된 방법을 적용하였고, 비선형해석을 통하여 제안된 방법의 정확성을 검증하였다. 제안된 방법은 단순계산으로 부재소성변형을 합리적으로 예측하지만, 정확한 부재소성변형 평가를 위해서는 비탄성 층간변위비의 정확한 예측이 필요한 것으로 나타났다. 제안된 방법은 향후 성능중심 내진설계에 활용할 수 있을 뿐만 아니라 기존 건물의 성능평가에도 활용될 수 있을 것이다.

Finite element analysis of long-term changes of the breast after augmentation mammoplasty: Implications for implant design

  • Myung, Yujin;Lee, Jong-Gu;Cho, Maenghyo;Heo, Chan Yeong
    • Archives of Plastic Surgery
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    • 제46권4호
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    • pp.386-389
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    • 2019
  • The development of breast implant technology continues to evolve over time, but changes in breast shape after implantation have not been fully elucidated. Thus, we performed computerized finite element analysis in order to better understand the trajectory of changes and stress variation after breast implantation. The finite element analysis of changes in breast shape involved two components: a static analysis of the position where the implant is inserted, and a dynamic analysis of the downward pressure applied in the direction of gravity during physical activity. Through this finite element analysis, in terms of extrinsic changes, it was found that the dimensions of the breast implant and the position of the top-point did not directly correspond to the trajectory of changes in the breast after implantation. In addition, in terms of internal changes, static and dynamic analysis showed that implants with a lower top-point led to an increased amount of stress applied to the lower thorax. The maximum stress values were 1.6 to 2 times larger in the dynamic analysis than in the static analysis. This finding has important implications for plastic surgeons who are concerned with long-term changes or side effects, such as bottoming-out, after anatomic implant placement.

차량용 서스펜디드 페달 구조체의 피로 내구 분석 및 설계 개선 (Fatigue and Robust Analysis for Improving the Suspended Pedal of Vehicles)

  • 이우형;황범철;김철;배원병
    • 한국정밀공학회지
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    • 제26권7호
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    • pp.105-111
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    • 2009
  • This study was carried out to evaluate structural stability of the suspended plastic pedal used in vehicles and to predict its fatigue life with the results obtained from finite element analysis. And also shape optimization was performed to reduce its weight. Structural analysis of the suspended plastic pedal was based on the evaluation tests such as static test, stiffness test, and fatigue test in the actual field, which were frequently carried out in the companies manufacturing plastic pedals. The evaluation for the plastic pedal was carried out by structural and fatigue analyses using a commercial FEA program and according to it, maximum stress and strain and fatigue life of the pedal satisfied all the requirements in the evaluation tests. The results of structural analysis of the suspended plastic pedal were used in the fatigue analysis. Fatigue test was performed to verify validity of the theoretical fatigue life of the plastic pedal. And the life by theoretical calculation was in good agreement with that by the experiment. Object function for optimizing shape of the plastic pedal is its volume, and total volume of the plastic pedal was reduced to about 11.7% through shape optimization.

플라스틱 직교 보강 구조물의 휨특성에 대한 실험과 해석적 접근 (Experimental and Numerical Approach for Warpage Characteristics of Plastic Orthogonal Stiffened Structure)

  • 김무연;조용주;이성희
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1997-2000
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    • 2005
  • In this work, the effects of orthogonal ribs on warpage of plastic structure through injection molding process were investigated. Three kinds of injection molds were prepared to perform injection molding experiments of orthogonal stiffened plastic plate. The warpage of each injection molded specimen was measured using 3D CMM. And plastic injection molding analysis with commercial code was performed for the presented model. Numerical results of injection molding analysis were compared with those of experiments. It was shown that orthogonal ribs have a significant effect on the warpage of the structure in both cases of experiment and numerical analysis.

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탄소성문제 적용을 위한 영역분할법 (Domain Decomposition Method for Elasto-Plastic Problem)

  • 배병규;이준성
    • 한국산학기술학회논문지
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    • 제12권8호
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    • pp.3384-3390
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    • 2011
  • 본 논문은 탄소성 구조해석을 위한 병렬유한요소해석에 필요한 영역분할법에 대해 제시하고 있다. 유한요소해석을 위한 알고리즘으로서 CG방법과 결합한 영역분할법을 이용하였다. 적용된 영역분할법은 탄소성문제를 해석하는데 직접적으로 사용되어 지며 효용성 검토를 위해 3차원 탄소성 구조문제에 적용하여 해석해 본 결과 높은 병렬효과를 발휘함을 알 수 있었다.

되풀이 소성영역 크기를 이용한 피로 균열 닫힘 거동의 유한요소해석 (Finite Element Analysis for Fatigue Crack Closure Behavior Using Reversed Plastic Zone Size)

  • 최현창
    • 대한기계학회논문집A
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    • 제27권10호
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    • pp.1703-1711
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    • 2003
  • An elastic-plastic finite element analysis is performed to investigate detailed closure behaviour of fatigue cracks in residual stress fields and the numerical results are compared with experimental results. The finite element analysis performed under plane stress using contact elements can predict fatigue crack closure behaviour. The mesh of constant element size along crack surface can not predict the opening level of fatigue crack. Specially, the mesh of element sizes depending upon the reversed plastic zone size included the effect of crack opening point can precisely predict the opening level. By using the concept of the mesh of element sizes depending upon the reversed plastic zone size included the effect of crack opening point, the opening level of fatigue crack can be determined very well.