• 제목/요약/키워드: Elastic edge support

검색결과 5건 처리시간 0.023초

Forced vibrations of an elastic circular plate supported by unilateral edge lateral springs

  • Celep, Zekai;Gencoglu, Mustafa
    • Structural Engineering and Mechanics
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    • 제83권4호
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    • pp.451-463
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    • 2022
  • The present study deals with forced vibrations of an elastic circular plate supported along its circular edge by unilateral elastic springs. The plate is assumed to be subjected to a uniformly distributed and a concentrated load. Under the combination of these loads, equations of motion are explicitly derived for static and dynamic response analyses by assuming a series of the displacement functions of time and other unknown parameters which are to be determined by employing Lagrangian functional. The approximate solution is sought by applying the Lagrange equations of motions by using the potential energy of the external forces that includes the contributions of the edge forces and the external moments, i.e., those of the effects of the boundary condition to the analysis. For the numerical treatment of the problem in the time domain, the linear acceleration procedure is adopted. The tensionless character of the support is taken into account by using an iterative process and, the coordinate functions for the displacement field are selected to partially fulfill the boundary conditions so that an acceptable approximation can be achieved faster. Numerical results are presented in the figures focusing on the nonlinearity of the problem due to the plate lift-off from the unilateral springs at the edge support.

임의의 탄성 경계 지점으로 지지된 판과 쉘의 기하학적 선형 및 비선형해석 (Geometrically Linear and Non-linear Analysis of Plates and Shells Resting on Arbitrary Elastic Edge Supports)

  • 이원홍;한성천;박원태
    • 한국방재학회 논문집
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    • 제8권3호
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    • pp.11-21
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    • 2008
  • 여러 가지 하중을 받는 임의의 탄성 경계 지지된 판과 쉘의 기하학적 선형 및 비선형해석을 수행하였다. 가정변형률 9절점 쉘 요소를 이용하였으며, 임의의 탄성 경계 지지를 표현하기 위해 6개의 자유도를 갖는 스프링 요소가 사용되었다. 탄성 경계지지 구조물 해석의 응용을 위하여, 여러 형태의 단부 지지를 받는 판과 쉘이 분석되었으며, 이들 단부 지지에 대한 휨 거동을 정확히 얻을 수 있었다. 6개의 스프링으로 표현된 탄성 경계 지지 조건에 대하여 적절한 결과를 얻을 수 있었다. 해석 결과로부터 본 연구의 해석 방법이 임의의 탄성 경계 조건을 갖는 판과 쉘의 거동을 해석하는데 폭넓게 사용될 수 있음을 알 수 있었다.

미분변환법을 이용한 축대칭 원판의 자유 진동 해석 (Free Vibration Analysis of Axisymmetrical Circular Plate by Using Differential Transformation Method)

  • 신영재;윤종학;지영철;김준년;페디나노
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.604-607
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    • 2005
  • The free vibration of solid circular plates has been studied using the differential transformation method(DTM). The effects such as mass at edge and elastic restraints have been considered. In order to avoid the singularity problem at the solid circular center two regularity conditions were applied with respect to the number of circumferential nodal line. The non-dimensional natural frequencies of the general circular plates were obtained for various boundary conditions. The results obtained by this method were compared with previous works. DTM showed fast convergency, accuracy, efficiency and validity in solving vibration problem of general circular plates.

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코의 "진피연골인대"의 해부학 (Anatomy of Pitanguy's Dermocartilaginous Ligament)

  • 박덕준;한승규;정성호;김우경
    • Archives of Plastic Surgery
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    • 제34권2호
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    • pp.176-180
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    • 2007
  • Purpose: Pitanguy conducted a series of anatomical studies on "dermocartilaginous ligament" of the nose. However, information on its structure is as yet insufficient, especially in terms of its origin, insertion, and relationships with surrounding tissues. In addition, some of the histologic findings described by Pitanguy are controversial. The present study was undertaken to clarify the anatomy of the "dermocartilaginous ligament". Methods: Sixteen cadaver noses were examined macroscopically and histologically to determine the presence, origin, insertion, composition, and relationship of the "dermocartilaginous ligament" with surrounding structures. Results: The structure originated from the deep layer of the transverse nasalis muscle and terminated at the caudal edge of the septal cartilage in all 16 cadavers. However, in three cadavers the insertion extended to the orbicularis oris muscle. No direct connection was found between the structure and dermis of dorsal nasal skin. The dermocartilaginous ligaments were mainly composed of a condensation of thin collagen bundles, which were interwoven and without any regular orientation. Elastic fibers were also present in small numbers, and there were few amorphous ground substances. Neither muscle fibers nor chondrocytes was identified within dermocartilaginous ligaments. Conclusion: Our macroscopic and histologic findings of the structure do not support the use of the term "dermocartilaginous ligament". According to its origin, insertion, and histologic findings, we recommend that this structure be referred to as the "median musculocartilaginous fascia".

위편조직(緯編組織)의 물성(物性)에 관한 연구(硏究) (A Study of the Physical Properties of Weft Knit Fabrics)

  • 김인숙;이순홍
    • 패션비즈니스
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    • 제2권4호
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    • pp.93-101
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    • 1998
  • Knit products which had been limited only to underwear, recently became popularized, fashionized and highly classified covering even outer garments such as sportswear like golfwear, woman's dress, and man' s suit. As fashion cycle is getting shorter and the more a nation advanced prefers knit to woven fabrics knit industry has a very bright prospect, particularly woman's knit which is sensitive to fashion can be said as a fashion product with high value added. This study is to grasp the physical properties of stitch which are fundamental to the development of knit products. For this purpose, 2/20s of 100% wool were woven by the author of this study to basic plain stitch, rib stitch, varied transfer stitch, and float stitch on a SEMASEIKI cross knitter 7G to test the physical properties, and the result was as follows; 1. As for the relation between knit stitch and rate of extension recovery, rate of extension recovery was higher in the course direction than in the wale direction of three stitches except transfer stitch; rib stitch showed the highest rate of extension recovery in the course direction while float stitch showed the highest rate of extension recovery in the wale direction. 2. As for the relation between knit stitch and bursting strength elastic rib stitch showed higher bursting strength to indicate elasticity is an important factor of bursting strength and float stitch showed higher bursting strength too to indicate that the floating yarn on the surface plays a role of support. 3. As for the relation between knit stitch and air permeability perforated transfer stitch showed the lowest air permeability to prove that the size of perforation affects on the air permeability a great deal. 4. As for the relation between knit stitch and warmth retaining rib stitch through two lined needle bar showed the highest degree. The reason the warmth of perforated transfer stitch didn't decrease much was because the perforation wasn't big enough and content of air increased from the unevenness of the perforated parts through stitch variation. Based upon this result, each stitch can be characteristically summarized as follows; plain stitch showed a stable condition of knit cloth in four kinds of physical property test. And rib stitch is proper to tighten the edge of sleeve or clothe making use of its excellent extension recovery and to make socks for the highest bursting strength and warmth retaining. In the case of transfer stitch, seasonable designs can be taken by controlling the size of loop. Considering the pleasantness, underwear should be made of stitches with good air permeability float stitch was revealed to have color and pattern effects and a great bursting strength. This study has limitations in the aspect that it dealed with a small part of various knit stitches and the items of physical property test were not enough. The author of this study hopes that further studies would make deeper understandings about knit stitch based on more varied stitches and physical property tests ultimately to contribute to the development of fashionable designs proper to maximize the usage, function and originality.

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