• 제목/요약/키워드: plastic displacement

검색결과 787건 처리시간 0.021초

A rare case of implant displacement to the contralateral side after gluteal augmentation

  • Rueda, Juan Dario Alviar;Miranda-Diaz, Audrey Jose;Cely, Adriana Gonzalez;Leon, Diana Carolina Navarro
    • Archives of Plastic Surgery
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    • 제47권4호
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    • pp.360-364
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    • 2020
  • In this report, we present a rare case of solid silicone implant displacement to the contralateral side after aesthetic gluteal augmentation, a phenomenon that has never been reported before in the literature. A 29-year-old woman with a history of gluteal augmentation 9 months previously and soft tissue infection presented for a consultation due to 3 days of sudden progressive pain in the right gluteus with erythema and edema, without a history of trauma. Displacement of the left gluteal implant to the right gluteal pocket was shown by magnetic resonance imaging. Because the patient refused implant removal, the decision was made to perform capsulotomy, to reconstruct the gluteal pockets, and to preserve the implants. The patient showed a satisfactory early and late postoperative course. Possible causes of this complication include poor surgical technique, with insufficient tissue preservation to keep the pockets apart, and the presence of seroma or hematoma that favored an infectious process, thereby leading to deterioration of the dissected soft tissues with dehiscence of the wound favoring the displacement of the implant.

Load-ratio 법에 의한 SA508C-3와 알루미늄 합금의 탄소성 파괴저항 곡선평가 (Evaluation on elastic-plastic fracture resistance curve of SA508C-3 and aluminum alloy steels by load-ratio method)

  • ;윤한기;차귀준
    • 한국해양공학회지
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    • 제10권2호
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    • pp.98-105
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    • 1996
  • A method is proposed to evaluate the elastic-plastic fracture resistance curve only with load displacement records without the crack length measurement in CT specimen. This method is based on the idea that the effect of plastic deformation and the crack growth can be measured only by using a load-displacement record. If we know the reference-load curve representing the hardening of specimen, then the crack extension can be calculated by the elastic compliance determined from the load ratio. The results of this proposed method were compared to those of the elastic-plastic fracture resistance curve for the ASTM standard unloading compliance method. The experimental results for two kinds of ductile materials showed that the proposed method well simulates the material J-R curves. This method is currently applied for CT specimens. but it can be extended to the other specimen geometries.

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Three-Dimensional Surface Imaging is an Effective Tool for Measuring Breast Volume: A Validation Study

  • Lee, Woo Yeon;Kim, Min Jung;Lew, Dae Hyun;Song, Seung Yong;Lee, Dong Won
    • Archives of Plastic Surgery
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    • 제43권5호
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    • pp.430-437
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    • 2016
  • Background Accurate breast volume assessment is a prerequisite to preoperative planning, as well as intraoperative decision making in breast reconstruction surgery. The use of three-dimensional surface imaging (3D scanning) to assess breast volume has many advantages. However, before employing 3D scanning in the field, the tool's validity should be demonstrated. The purpose of this study was to confirm the validity of 3D-scanning technology for evaluating breast volume. Methods We reviewed the charts of 25 patients who underwent breast reconstruction surgery immediately after total mastectomy. Breast volumes using the Axis Three 3D scanner, water-displacement technique, and magnetic resonance imaging (MRI) were obtained bilaterally in the preoperative period. During the operation, the tissue removed during total mastectomy was weighed and the specimen volume was calculated from the weight. Then, we compared the volume obtained from 3D scanning with those obtained using the water-displacement technique, MRI, and the calculated volume of the tissue removed. Results The intraclass correlation coefficient (ICC) of breast volumes obtained from 3D scanning, as compared to the volumes obtained using the water-displacement technique and specimen weight, demonstrated excellent reliability. The ICC of breast volumes obtained using 3D scanning, as compared to those obtained by MRI, demonstrated substantial reliability. Passing-Bablok regression showed agreement between 3D scanning and the water-displacement technique, and showed a linear association of 3D scanning with MRI and specimen volume, respectively. Conclusions When compared with the classical water-displacement technique and MRI-based volumetry, 3D scanning showed significant reliability and a linear association with the other two methods.

STS 316L의 재결정 열처리법을 이용한 구속효과 평가 (Evaluation of the Plastic Region Using Recrystallization Heat Treatment for Constraint Effect with STS 316L)

  • 한민수;장석기
    • Journal of Advanced Marine Engineering and Technology
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    • 제33권4호
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    • pp.539-544
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    • 2009
  • The constraint effect $A_2$ has to be evaluated within plastic region near crack tip front using opening displacement. Plastic boundary and stress or strain conditions in the vicinity of the crack tip using recrystallization heat treatment was represented. It was found that the plastic deformation boundary by recrystallization heat treatment method was the true strain of ${\epsilon}t$ = 0.05mm/mm. With the estimation of constraint effects $A_2$, the region of proper displacement measurement point near crack tip was between 0mm and 1mm distance toward direction of crack propagation, and was between 1mm to 3mm distance toward direction of load line.

Ductility-based seismic design of precast concrete large panel buildings

  • Astarlioglu, Serdar;Memari, Ali M.;Scanlon, Andrew
    • Structural Engineering and Mechanics
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    • 제10권4호
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    • pp.405-426
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    • 2000
  • Two approximate methods based on mechanism analysis suitable for seismic assessment/design of structural concrete are reviewed. The methods involve use of equal energy concept or equal displacement concept along with appropriate patterns of inelastic deformations to relate structure's maximum lateral displacement to member and plastic deformations. One of these methods (Clough's method), defined here as a ductility-based approach, is examined in detail and a modification for its improvement is suggested. The modification is based on estimation of maximum inelastic displacement using inelastic design response spectra (IDRS) as an alternative to using equal energy concept. The IDRS for demand displacement ductilities are developed for a single degree of freedom model subjected to several accelerograms as functions of response modification factor (R), damping ratios, and strain hardening. The suggested revised methodology involves estimation of R as the ratio of elastic strength demand to code level demand, and determination of design base shear using $R_{design}{\leq}R$ and maximum displacement, determination of plastic displacement using IDRS and subsequent local plastic deformations. The methodology is demonstrated for the case of a 10-story precast wall panel building.

일반화된 Hoek-Brown 암반에 굴착된 원형터널의 내공변위 특성 분석 (Numerical Investigation of the Radial Convergence of Circular Tunnel Excavated in Rock Mass for Generalized Hoek-Brown)

  • 임광옥;이연규
    • 터널과지하공간
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    • 제28권1호
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    • pp.59-71
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    • 2018
  • 일반화된 Hoek-Brown(GHB) 파괴조건식은 GSI 지수를 통해 현장 암반의 절리상태를 체계적으로 고려하여 암반의 강도를 예측하는 파괴함수로서 암반공학적 설계에 널리 활용되고 있다. 이 연구에서는 절리성 암반에 굴착된 원형터널의 내공변위 특성을 분석하기 위하여 GHB 파괴조건식을 항복함수로 활용한 2차원 탄소성 유한요소해석을 수행하였다. 이 과정에서 소성포텐셜 함수의 가정이 탄소성 변위 해석결과에 미치는 영향도 고찰하였다. 탄소성 해석에서는 넓은 범위의 측압비(K) 변화와 암반의 양호성을 나타내는 GSI 값의 변화가 동시에 고려되었다. 각 측압비에 대해 GSI 값의 변화에 따른 측벽변위/천정변위 비를 계산하여 내공변위 발생특성을 분석하였다. 해석결과 측벽변위/천정변위 비는 측압비의 크기뿐만 아니라 GSI 값의 범위에 큰 영향을 받는 것으로 나타났다. 특히 GSI 값이 매우 작은 불량한 암반의 경우 탄소성해석으로 계산한 측벽변위/천정변위 비는 탄성이론으로 계산한 결과와 반대의 경향을 보였다. 또한 소성포텐셜 함수의 형태에 따른 측벽변위/천정변위 비 변화는 대체로 유사한 경향성을 보이는 것으로 나타났다.

Drift displacement data based estimation of cumulative plastic deformation ratios for buildings

  • Nishitani, Akira;Matsui, Chisa;Hara, Yushiro;Xiang, Ping;Nitta, Yoshihiro;Hatada, Tomohiko;Katamura, Ryota;Matsuya, Iwao;Tanii, Takashi
    • Smart Structures and Systems
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    • 제15권3호
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    • pp.881-896
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    • 2015
  • The authors' research group has developed a noncontact type of sensors which directly measure the inter-story drift displacements of a building during a seismic event. Soon after that event, such seismically-induced drift displacement data would provide structural engineers with useful information to judge how the stories have been damaged. This paper presents a scheme of estimating the story cumulative plastic deformation ratios based on such measured drift displacement information toward the building safety monitoring. The presented scheme requires the data of story drift displacements and the ground motion acceleration. The involved calculations are rather simple without any detailed information on structural elements required: the story hysteresis loops are first estimated and then the cumulative plastic deformation ratio of each story is evaluated from the estimated hysteresis. The effectiveness of the scheme is demonstrated by utilizing the data of full-scale building model experiment performed at E-defense and conducting numerical simulations.

외상성 상악동 안구탈출의 치험례: 증례보고 (Traumatic Displacement of the Globe into the Maxillary Sinus: Case Report)

  • 임찬수;강동희
    • Archives of Plastic Surgery
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    • 제34권4호
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    • pp.524-527
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    • 2007
  • Purpose: Globe displacement due to a blowout fracture is a rare clinical phenomenon. The authors present reduction of a globe displacement to the maxillary sinus due to trauma suffered in a fall and the reconstruction of a large defect left in the medial and inferior orbit. Methods: A 39-year-old male patient was unable to open his left eye after being struck on the periorbital area by a metal edge. Laceration was not noted in that area but we were unable to observe the intraorbital globe. A facial computed tomography (CT) scan showed that the globe was displaced through the maxillary sinus. A transconjunctival approach was used to access the infraorbital margin and the globe entrapped in the inferior margin of the orbit was successfully reduced. A large defect in the medial and inferior orbit was reconstructed using a graft from the iliac bone. Results: In 5 months after the operation, no atrophy of the globe was seen. Both sides retained a similar shape. A satisfactory functionality outcome in terms of improved extraocular muscle movement, and a satisfactory aesthetical outcome were achieved. Conclusion: The authors report the reduction of a globe displaced to the maxillary sinus following a fall and the reconstruction of the large defect left in the medial and inferior orbit.

A novel approach for predicting lateral displacement caused by pile installation

  • Li, Chao;Zou, Jin-feng;Li, Lin
    • Geomechanics and Engineering
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    • 제20권2호
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    • pp.147-154
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    • 2020
  • A novel approach for predicting lateral displacement caused by pile installation in anisotropic clay is presented, on the basis of the cylindrical and spherical cavities expansion theory. The K0-based modified Cam-clay (K0-MCC) model is adopted for the K0-consolidated clay and the process of pile installation is taken as the cavity expansion problem in undrained condition. The radial displacement of plastic region is obtained by combining the cavity wall boundary and the elastic-plastic (EP) boundary conditions. The predicted equations of lateral displacement during single pile and multi-pile installation are proposed, and the hydraulic fracture problem in the vicinity of the pile tip is investigated. The comparison between the lateral displacement obtained from the presented approach and the measured data from Chai et al. (2005) is carried out and shows a good agreement. It is suggested that the presented approach is a useful tool for the design of soft subsoil improvement resulting from the pile installation.

Elasto-plastic Analysis of Circular Cylindrical Shell under Horizontal Load by Rigid-bodies Spring Model

  • 박강근
    • 한국공간구조학회논문집
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    • 제6권3호
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    • pp.87-92
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    • 2006
  • This paper is a study on the experiment and elasto-plastic discrete limit analysis of reinforced concrete circular cylindrical shell by the rigid-bodies spring model. In the rigid bodies-spring model, each collapsed part or piece of structures at the limiting state of loading is assumed to behave like rigid bodies. The present author propose new discrete elements for elasto-plastic analysis of cylindrical shell structures, that is, a rectangular-shaped cylindrical element and a rhombus-shaped cylindrical element for the improvement and expansion of this rigid-bodies spring model. In this study, it is proposed how this rigid element-bodies spring model can be applied to the elasto-plastic discrete limit analysis of cylindrical shell structures. Some numerical results of elasto-plastic discrete limit analysis and experimental results such as the curve of load-displacement and the yielding and fracturing pattern of circular cylindrical shell under horizontal load are shown.

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