• Title/Summary/Keyword: curvature analysis

검색결과 1,154건 처리시간 0.032초

유방 유형에 따른 브래지어 선정 프로그램 (Program for the Selection of Brassieres Depending on Breast Types)

  • 이현영;정수경;홍경희
    • 한국생활과학회지
    • /
    • 제14권3호
    • /
    • pp.467-473
    • /
    • 2005
  • The integrative Internet program was developed for the selection of optimal brassiere components according to the breast types of middle-aged women. In this program, a customer is classified into a certain group through three steps of a discriminant analysis. Three variables used in the analysis include breast volume, radii of curvature of under-breast curve, and a distance between inner breast points. Using individual data of three variables, the optimal brassiere components, i.e. brassiere cup size, curvature of front panel and wire, distance between cups, are suggested for each customer. Discrimination of breast types using only 2D measurements is also included for those who do not have easy access to a 3D measurement device.

  • PDF

굽힘 하중 하에서 굴곡진 보강섬유를 가진 두꺼운 복합재료 보의 응력 분포 해석 (Stress and Strain Analyses of Thick Composites with Fiber Waviness under Flexural Loading)

  • 이승우;전흥재
    • 한국복합재료학회:학술대회논문집
    • /
    • 한국복합재료학회 1999년도 추계학술발표대회 논문집
    • /
    • pp.95-100
    • /
    • 1999
  • A FEA(finite element analysis model) was proposed to study stress and strain distributions in thick composites with fiber waviness and initial curvature under flexural loading. Three types of model with initial curvature were considered in this study: flat, concave and concave models. In the analysis, both material and geometrical nonlinearities were incorporated. Four point flexural tests were conducted on the flat specimens to obtain the flexural behavior of thick composites experimentally. It was concluded that the predictions from the models were in good agreement with the experimental results. It was shown that the stress and strain distributions as well as nonlinear flexural behaviors of thick composites were significantly affected by the fiber waviness and initial curvature.

  • PDF

An Analysis of Femoral Bone Remodeling Using Topology Optimization Method

  • Choi J. B.
    • 대한의용생체공학회:의공학회지
    • /
    • 제26권6호
    • /
    • pp.365-372
    • /
    • 2005
  • Topology optimization method has a great advantage and capability over a conventional shape optimization technique because it optimizes a topology as well as a shape and size of structure. The purpose of the present study, using topology optimization method with an objective function of minimum compliance as a mechanism of bone remodeling, is to examine which shape factors of femur is strongly related with the curvature of femoral shaft. As is expected, the optimized curvature increased definitely with neck angle among the shape factors and showed a similar trend with the measured curvature to neck angle. Therefore, the topology optimization method can be successfully applied in the analysis of bone remodeling phenomenon in the subsequent studies.

용접변형에의 곡률의 영향에 관한 연구 (On the Effect of Plate Curvature on Welding Deformation)

  • 이주성;이진태
    • 한국해양공학회지
    • /
    • 제24권2호
    • /
    • pp.67-73
    • /
    • 2010
  • A simplified finite element analysis has been used to predict the weld-induced deformation to bead-on-plate welding of steel plates having curvatures in the welding direction. In this study, the equivalent loading method based on inherent strain was used to investigate the effect of longitudinal curvature on the weld-induced deformation of curved plates. Equivalent loads were derived from the inherent strain distribution around the weld line, and the loads were used for linear finite element analyses. These kinds of numerical simulations can, of course, be performed by using the rigorous thermalelastic-plastic analysis method. This approach is not, however, practical for use in weld-induced deformation analysis of large and complex structures, such as ship structures, in view of computing time and cost. The present equivalent load approach has been applied to several plate models having curvatures in the welding direction, and the results are compared with those obtained by thermal-elastic-plastic analysis and also with those obtained by the other simplified method found in reference. As far as the present results are concerned, the weld-induced deformation of curved plates can be accurately predicted by the method presented in this paper.

단섬유 복합재료 사출성형물의 잔류응력 측정 (Measurement of Residual Stress Distribution in Injection-Molded Short Fiber Composites)

  • 김상균;이석원;윤재륜
    • 한국복합재료학회:학술대회논문집
    • /
    • 한국복합재료학회 2001년도 추계학술발표대회 논문집
    • /
    • pp.61-63
    • /
    • 2001
  • Residual stress distribution in injection-molded short fiber composites was determined using layer-removal method. Polysterene with 3 vol% carbon fibers was injection-molded into the tensile specimen. With milling machine layer-removal process was conducted and the curvature data were acquired. Treuting and Read analysis which is assuming isotropic material, and White analysis considering anisotropy due to the fiber orientation were used to calculate residual stress of the flow direction through the thickness direction and compared with each other.

  • PDF

Analysis of the Pressure Distribution for Press Shoe considering Partially Changed Curvature of Bearing Surface

  • Park, Sang-Shin;Park, Young-Ha;Lee, Young-Ze;Han, Man-Cheol
    • 한국윤활학회:학술대회논문집
    • /
    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
    • /
    • pp.123-124
    • /
    • 2002
  • A press shoe is an element of a machine for squeezing water from wood pulp in the field of manufacturing paper. This is used to compress the pulp enveloped by felt sheet with a large roller. The squeezing force is made by hydraulic pressure. The press shoe has a mechanism similar to a partial hydrostatic bearing. The pressure profile between press shoe and roller affects their squeezing ability, and partial peak pressure can tear the wet pulp. The curvature of the surface of press shoe varies to reduce the peak pressure and increase the mean pressure simultaneously. Therefore, the prediction of pressure distribution considering partially changed curvature of hydrostatic bearing is very important for designing the press shoe. In this study, the difference formulation of Reynolds' equation for partial hydrostatic bearing is by direct numerical method and a computer program to calculate the pressure distribution is developed. We investigate the effect of partially changed curvature of bearing surface on the pressure distribution. Other design parameter for hydrostatic bearing such as depth of pocket and relative velocity are also studied.

  • PDF

Failure life estimation of sharp-notched circular tubes with different notch depths under cyclic bending

  • Lee, Kuo-Long;Chang, Kao-Hua;Pan, Wen-Fung
    • Structural Engineering and Mechanics
    • /
    • 제60권3호
    • /
    • pp.387-404
    • /
    • 2016
  • In this paper, the response and failure of sharp-notched 6061-T6 aluminum alloy circular tubes with five different notch depths of 0.4, 0.8, 1.2, 1.6 and 2.0 mm subjected to cyclic bending were experimentally and theoretically investigated. The experimental moment-curvature relationship exhibits an almost steady loop from the beginning of the first cycle. And, the notch depth has almost no influence on its relationship. However, the ovalization-curvature relationship exhibits a symmetrical, increasing, and ratcheting behavior as the number of cycles increases. In addition, a higher notch depth of a tube leads to a more severe unsymmetrical trend of the ovalization-curvature relationship. Focusing on the aforementioned relationships, the finite element software ANSYS was used to continue the related theoretical simulation. Furthermore, the five groups of tubes tested have different notch depths, from which five unparallel straight lines can be observed from the relationship between the controlled curvature and the number of cycles required to produce failure in the log-log scale. Finally, a failure model was proposed to simulate the aforementioned relationship. Through comparison with the experimental data, the proposed model can properly simulate the experimental data.

U-자형 곡관내의 유동특성에 대한 수치해석적 연구 (NUMERICAL SIMULATION OF THE FLOW CHARACTERISTICS INSIDE A U-TYPE TUBE)

  • 고동훈;강동진;송동주
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2009년 춘계학술대회논문집
    • /
    • pp.97-103
    • /
    • 2009
  • A numerical study of the flow characteristics inside a U-type circular tube is carried out in this paper. The numerical simulations carried out by using a Navier-Stokes code which is commercially available. Before detailed numerical simulations, validation of present numerical approach is made by comparing numerical solutions with experimental data. Numerical simulations are performed to study the effect of curvature on the flow characteristics inside a U-type tube. Numerical solutions show that a significant effect on the secondary flow structure in the cross section of the tube, especially in the curved section is shown when the curvature ratio, ratio of curvature to tube diameter, is smaller than about 3.5. As the curvature ratio decreases below 3.5, a counter rotating vortex is found below the primary vortex in the cross section of the tube. Another dramatic change of the flow structure is the formation of streamwise separation zone when the curvature ratio is decreased below 1.25.

  • PDF

Analysis of the Pressure Distribution for Press Shoe considering Partially Changed Curvature of Bearing Surface

  • Park, Sang-Shin;Park, Young-Ha;Lee, Young-Ze;Han, Man-Cheol
    • KSTLE International Journal
    • /
    • 제3권2호
    • /
    • pp.90-94
    • /
    • 2002
  • A press shoe is an element of a machine for squeezing water from wood pulp in the field of manufacturing paper. This is used to compress the pulp enveloped by felt sheet with a large roller. The squeezing farce is made by hydraulic pressure. The press shoe has a mechanism similar to a partial hydrostatic bearing. The pressure profile between press shoe and roller affects their squeezing ability, and partial peak pressure can tear the wet pulp. The curvature of the surface of press shoe varies to reduce the peak pressure and increase the mean pressure simultaneously, Therefore, the prediction of pressure distribution considering partially changed curvature of hydrostatic bearing is very important far designing the press shoe. In this study, the difference formulation of Reynolds equation far partial hydrostatic bearing is derived by direct numerical method and a computer program to calculate the pressure distribution is developed. We investigate the effect of partially changed curvature of bearing surface on the pressure distribution. Other design parameter far hydrostatic bearing such as depth of pocket and relative velocity are also studied.

Simplified Design Procedure for Reinforced Concrete Columns Based on Equivalent Column Concept

  • Afefy, Hamdy M.;El-Tony, El-Tony M.
    • International Journal of Concrete Structures and Materials
    • /
    • 제10권3호
    • /
    • pp.393-406
    • /
    • 2016
  • Axially loaded reinforced concrete columns are hardly exist in practice due to the development of some bending moments. These moments could be produced by gravity loads or the lateral loads. First, the current paper presents a detailed analysis on the overall structural behavior of 15 eccentrically loaded columns as well as one concentrically loaded control one. Columns bent in either single curvature or double curvature modes are tested experimentally up to failure under the effect of different end eccentricities combinations. Three end eccentricities ratio were studied, namely, 0.1b, 0.3b and 0.5b, where b is the column width. Second, an expression correlated the decay in the normalized axial capacity of the column and the acting end eccentricities was developed based on the experimental results and then verified against the available formula. Third, based on the equivalent column concept, the equivalent pin-ended columns were obtained for columns bent in either single or double curvature modes. And then, the effect of end eccentricity ratio was correlated to the equivalent column length. Finally, a simplified design procedure was proposed for eccentrically loaded braced column by transferring it to an equivalent axially loaded pin-ended slender column. The results of the proposed design procedure showed comparable results against the results of the ACI 318-14 code.