• 제목/요약/키워드: plastic rotation

검색결과 357건 처리시간 0.025초

단지신근 근피판을 이용한 하지 원위부 연부조직 결손의 재건 (Reconstruction of Soft Tissue Defect on Distal Leg with Extensor Digitorum Brevis Myo-Cutaneous Flap)

  • 이상윤;정호윤;김종엽;양정덕;박재우;조병채
    • Archives of Plastic Surgery
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    • 제33권4호
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    • pp.474-479
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    • 2006
  • Purpose: To report of a series of successful reconstruction of soft tissue defect on distal leg with extensor digitorum brevis myo-cutaneous flap. Methods: Between April 2002 to December 2004, 7 patients with soft tissue defect on distal leg were operated with Extensor Digiotorum Brevis myocutaneous flap. 6 of these patients had osteomyelitis. Results: Extensor Digiotorum Brevis myocutaneous flap were used in 6 patients and reverse flow flap was used in one patient. Average follow up was 19 months. All flap were survived 100% without any complication and osteomyelitis were controled in all cases. Aesthetic and functional out come were excellent on both recipient and donor sites. Conclusion: The advantages of this flap are effectively control of local wound infection, constant and reliable anatomical structures, adequately thin flap. Technical easiness for raising flap and wide arch of rotation. Extensor Digitorum Brevis myo-cutaneous flap is one of ideal option for the reconstruction of distal leg and foot defects.

미용단위를 고려한 안와 주변부의 선천성 거대모반의 단계적 치료 (Serial Reconstruction Considerating the Aesthetic Unit on Congenital Giant Nevus in Periorbital Area)

  • 조성현;김진우;정재학;김영환;선욱
    • Archives of Plastic Surgery
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    • 제37권4호
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    • pp.465-468
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    • 2010
  • Purpose: Soft tissue deformity and skin defect after tumor resection in the periorbital area can cause trouble in the function of eyelid as well as in the aspect of external appearance. Therefore, as cosidering reconstruction in periorbital area, detailed assessment of both functional and aesthetic property are required. thus, the purpose of this study is to examine an appropriate reconstruction through clinical cases. Methods: A 14-year-old girl with congenital giant hairy nevus on right periorbital area was selected. Her first visit to our plastic surgery outpatient clinic was on July 2006. Since then, she has undergone staged removal of lesions and reconstruction by various flap technique such as pedicled island flap, forehead galeal flap, paramedian forehead flap, cheek rotation & advancement flap. Results: In the case of this girl, most lesions were removed and replaced by normal skins. Although there was the difference of skin color after skin graft, such difference was not noticeable and section scar by skin flaps was slight. There was no obvious dysfunction in the eyelids and the girl and her parents were satisfied with results after the surgery. Conclusions: In the reconstruction of soft tissue defect or soft tissue deformity and contracture, it is required to choose appropriate reconstruction method, considering aesthetic and functional aspects depending on aesthetic unit sufficiently.

Cyclic testing of steel I-beams reinforced with GFRP

  • Egilmez, O. Ozgur;Yormaz, Doruk
    • Steel and Composite Structures
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    • 제11권2호
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    • pp.93-114
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    • 2011
  • Flange and web local buckling in beam plastic hinge regions of steel moment frames can prevent beam-column connections from achieving adequate plastic rotations under earthquake-induced forces. This threat is especially valid for existing steel moment frame buildings with beams that lack adequate flange/web slenderness ratios. As the use of fiber reinforced polymers (FRP) have increased in strengthening and repair of steel members in recent years, using FRPs in stabilizing local instabilities have also attracted attention. Previous computational studies have shown that longitudinally oriented glass FRP (GFRP) strips may serve to moderately brace beam flanges against the occurrence of local buckling during plastic hinging. An experimental study was conducted at Izmir Institute of Technology investigating the effects of GFRP reinforcement on local buckling behavior of existing steel I-beams with flange slenderness ratios (FSR) exceeding the slenderness limits set forth in current seismic design specifications and modified by a bottom flange triangular welded haunch. Four European HE400AA steel beams with a depth/width ratio of 1.26 and FSR of 11.4 were cyclically loaded up to 4% rotation in a cantilever beam test set-up. Both bare beams and beams with GFRP sheets were tested in order to investigate the contribution of GFRP sheets in mitigating local flange buckling. Different configurations of GFRP sheets were considered. The tests have shown that GFRP reinforcement can moderately mitigate inelastic flange local buckling.

할선강성해석법을 이용한 모멘트저항골조의 모멘트 재분배 (Moment Redistribution for Moment-Resisting Frames using Secant Stiffness Analysis Method)

  • 박홍근;김창수;엄태성
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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    • pp.221-224
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    • 2008
  • 할선강성을 이용하여 모멘트저항골조의 모멘트재분배를 수행하는 선형해석법을 연구하였다. 제안된 방법에서는 모멘트재분배가 요구되는 부재의 소성힌지에 회전스프링을 모델링한 후, 이 스프링의 할선 강성을 조정하여 비탄성변형으로 인해 저감된 부재의 휨강성을 반영한다. 회전스프링의 할선강성을 조정하여 선형해석한 결과, 해당 부재와 전체 구조물에서 힘의 평형이 만족될 때까지 계산을 반복한다. 할선강성해석을 통해, 소성힌지의 비탄성변형에 의한 하중의 재분배가 고려될 수 있으며, 해당 소성힌지에서의 요구회전변형이 변형능력을 초과하지 않는지 비교함으로써 안전성을 평가할 수 있다. 검증을 위해, 제안된 방법은 기존의 연속보에 대한 실험연구와 비교되었으며, 기존건물의 평가에 적용되었다.

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강소성 유한요소법을 이용한 평면 이방성 재료의 디프 드로잉 해석 (Analysis of Deep Drawing of Planar Anisotropic Materials Using the Rigid- Plastic Finite Element Method)

  • 김형종;김동원
    • 대한기계학회논문집
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    • 제16권2호
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    • pp.248-258
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    • 1992
  • Three-dimensional rigid-plastic finite element formulation based on the membrane theory was described and a computer program for large deformation analysis was developed. In the formulation, normal and planar anisotropy of sheet material and rotation of the principal axes of anisotropy was taken into consideration. Sheet metal was assumed to be rigid-plastic material obeying Hill's quadratic yield criterion and its associated flow rule. Deep drawing process, as a preliminary test, for normal anisotropic material was analyzed in order to examine the validity of developed finite element program. The results were consistent with the existing finite element solutions or experimental data. The present study was mainly concerned with the influence of planar anisotropy on deformation behaviour. Finite element analysis and experiment were carried out for the whole process of deep drawing of planar anisotropic material. The computational and experimental results on the shape of ear, strain distribution and punch load were in good agreement.

T-스티프너 보강 CFT 기둥 - H형강보 실대형 접합부의 거동 (Behavior of CFT Column to H-Beam Full-Scale Connections with External T-Stiffeners)

  • 김영주;강창훈;신경재;오영석;문태섭
    • 한국강구조학회 논문집
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    • 제13권6호
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    • pp.715-723
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    • 2001
  • 이 논문은 T-스티프너보강된 GFT기둥-H형강보 실대형 접합부의 거동을 나타낸다. 수직요소와 수평요소로 구성된 6개 실험체의 T-스트프너는 보의 전소성모멘트에 대한 강도비를 주요변수로 하여 제작되었다. 실험을 통하여 얻은 주요 내용은 강도, 강성과 소성회전능력이다. 모든 실험체는 대체로 안정된 이력거동을 나타내었으며, 특히 수평요소는 수직요소보다 강도와 강성에 더욱더 큰 영향을 준다. 보의 소성회전성능에 있어서, 조기에 파단한 TS-2를 제외한 실험체들의 평균 보소성회전각은 2.97% rad.이다.

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대전자부 압박궤양을 가지고 있는 하지마비 환자에서 대퇴골 골절부위에 발생한 비정상적 골증식의 치험례 (A Case of Atypical Bone Growth after Femur Neck Fracture in the Paraplegic Patient with Trochanteric Sore)

  • 양정열;천지선
    • Archives of Plastic Surgery
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    • 제35권1호
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    • pp.92-95
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    • 2008
  • Purpose: Heterotopic ossification in pressure sore patients is reported to rarely develop, but once it occurs, it frequently causes joint stiffness and mobilization restriction. The aim of this article is to report our experience of atypical bone growing at femur neck fracture site with chronic, extensive pressure sore in patient with paraplegia secondary to spinal injury. Methods: A 28-year-old male patient presented with atypical bone growth at femur neck fracture site with pressure sore. He had undergone atypical growth bone removal and separation of united iliac bone and femur, and then pressure sore was covered by advanced rotation flap. Results: The patient mobilized hip joint and rode in a wheelchair. Complications such as dehiscence, infection, hematoma and flap necrosis did not occur. Conclusion: We experienced successful correction of atypical bone growth removal and recovery of pressure sore. We report our experience of atypical bone growth of fracture site and the related literature was reviewed.

A finite strip method for elasto-plastic analysis of thin-walled structures under pure bending

  • Cheung, M.S.;Akhras, G.;Li, W.
    • Structural Engineering and Mechanics
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    • 제8권3호
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    • pp.233-242
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    • 1999
  • In the present study, the elasto-plastic analysis of prismatic plate structures subjected to pure bending is carried out using the finite strip method. The end cross-sections of the structure are assumed to remain plane during deformation, and the compatibility along corner lines is ensured by choosing proper displacement functions. The effects of both the initial geometrical imperfections and residual stresses due to fabrication are included in the combined geometrically and materially nonlinear simulation. The von-Mises yield criterion and the Prandtl-Reuss flow theory of plasticity are applied in modelling the elasto-plastic behavior of material. Newton-Raphson iterations are carried out as the rotation of the end cross sections of the structure is increased step by step. The parameter representing the overall axial strain of structure is adjusted constantly during the iteration process in order to eliminate the resulting overall axial force on any cross-section of the structure in correspondence with the assumption of zero axial force in pure bending. Several numerical examples are presented to validate the present method and to investigate the effects of some material and geometrical parameters.

Reconstruction of a scalp defect due to cochlear implant device extrusion using a temporoparietal fascia flap and a split-thickness skin graft from the scalp

  • Kang, Jae Kyoung;Lee, Jae Seong;Suh, Michelle;Lim, Gil Chae;Shin, Myoung Soo;Yun, Byung Min
    • 대한두개안면성형외과학회지
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    • 제20권5호
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    • pp.319-323
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    • 2019
  • Cochlear implant extrusion, which is a common complication of cochlear implants, is generally repaired by a well visualized soft-tissue flap. A 61-year-old female patient with a medical history of schizophrenia who had a skin ulcer that caused cochlear implant extrusion, but that would be a stronger statement was referred to our department for removal of the implant and reconstruction of the resultant scalp defect. Accordingly, the broad defect was covered via rotation of a temporoparietal fascia flap (TPFF) using the superficial temporal artery, with the pedicle in the preauricular region as the pivot point. Coverage of TPFF was achieved with a split-thickness skin graft using the scalp as the donor site, which led to a quick recovery after the operation and satisfactory results in terms of aesthetics. This case suggests that a TPFF might be used as a flexible flap with low donor site morbidity for reconstructing cases of cochlear implant extrusion accompanied by a large full-layer scalp defect.

안면부 3도 화상 재건에서 하부 승모근 근피 유경 피판의 유용성 (Usefulness of the Lower Trapezius Myocutaneous Pedicle Flap for Reconstruction of Third Degree Facial Burn)

  • 김재현;최종민;정찬민;박명철
    • 대한화상학회지
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    • 제24권2호
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    • pp.64-67
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    • 2021
  • Free flap surgery is commonly used for extensive facial burn. However, free flap surgery requires long operation time and difficult technique. Also, it requires further procedure to prepare the recipient vessels. Hence, applying pedicle flap surgery instead of free flap surgery is effective for patients with facial burn. Among a wide range of pedicle flaps, we performed lower trapezius myocutaneous pedicle flap to patients with third degree facial burn and got satisfactory results without complications. Lower trapezius myocutaneous pedicle flap has a wide arc of rotation so that it can cover middle and lower part of the face. Furthermore, it is thinner than other myocutaneous pedicle flap that can be used for facial reconstruction. Due to these advantages, lower trapezius myocutaneous pedicle can be an attractive option for the reconstruction of facial burn.