• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2023년도 봄 학술논문 발표대회
• /
• pp.49-50
• /
• 2023

The purpose of this study was to review ways to increase mechanical performance and apply to actual structures by reinforcing AL perforated sheets, which are industrial by-products generated after capacitor production, with mortar to reinforce the stress of structural members. The AL perforated sheet was reinforced so that it behaves integrally at the position receiving compression, tension, and bending stress. It was confirmed that the stress received by the AL perforated sheet increased according to the number of reinforcements, and as a result, the mechanical properties were improved.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2023년도 봄 학술논문 발표대회
• /
• pp.85-86
• /
• 2023

This study confirmed the improvement of the Composite Waterproof Method in which the sheet layer is partially attached with perforated film and the joint is FRP-treated.

• 한국압력기기공학회 논문집
• /
• 제15권1호
• /
• pp.8-17
• /
• 2019

Perforated plates are used for the steam generator tube-sheet and the Reactor Vessel Closure Head in the Nuclear Power Plant. The ASME code, Section III Appendix A-8000, addresses the analysis of perforated plates, however, this analysis is only limited to the flat plate with a triangular perforation pattern. Based on the concept of the effective elastic constants, simulation of flat and spherical perforated plates and their equivalent solid plates were carried out using Finite Element Analysis (FEA). The isotropic material properties of the perforated plate were replaced with anisotropic material properties of the equivalent solid plate and subjected to the same loading conditions. The generated curves of effective elastic constants vs ligament efficiency for the flat perforated plate were in agreement with the design curve provided by ASME code. With this result, a plate with spherical curvature having perforations can be conveniently analyzed with equivalent elastic modulus and equivalent Poisson's ratio.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1994년도 춘계학술대회 논문집
• /
• pp.101-108
• /
• 1994

The sheet perforated with a uniform triangular pattern of round holes and subjected to in-plane stress f arbitrary biaxiality was investigated. The equivalent continuum approach was employed to develop a theoretical model for global analysis, which includes defining a yield criterion and the strain hardening in terms of apparent stresses and apparent strains. Finit element analysis and experiment tension test were performed to examine the validity of proposed yield criterion and strain hardening models of perforated sheets.

• 한국정밀공학회지
• /
• 제22권2호
• /
• pp.79-88
• /
• 2005

Evaluating the effective properties of materials containing various types of in-homogeneities is an important issue in the analysis of structures composed of those materials. A simple and effective method for the purpose is to impose the periodic displacement boundary conditions on the finite element model of a unit cell. Their theoretical background is explained based on the purely kinematical relations in the regularly spaced in-homogeneity problems, and the strategies to implement them into the analysis and to evaluate the homogenized material constants are introduced. The creep behavior of a thin sheet with square arrayed rectangular voids is characterized, where the orthotropy is induced by the presence of the voids. The homogenization method is validated through the comparison of the analysis of detailed model with that of the simplified one with the effective parameters.

• 한국정밀공학회지
• /
• 제21권1호
• /
• pp.181-188
• /
• 2004

Structural analysis for materials containing regularly spaced in-homogeneities is usually executed by using averaged material properties. For the homogenization process, a unit cell is defined and loaded somehow, and its response is investigated to evaluate the properties. The imposed loading conditions should accord to the behavior of unit cell immersed in the macroscopic structure in order to guarantee the accuracy of the effective properties. Each unit cell shows periodic variation of strain if the material is loaded uniformly, and in this study, direct implementation of this characteristic behavior is attempted on FE models of unit cell. Conventional finite element analysis tool can be used without any modification, and the boundary of unit cell is constrained in a way that the periodicity is satisfied. The proposed method is applicable to skew arrayed in-homogeneity problems. The flexibility matrix relating tonsorial stress and strain components in skewed rectilinear coordinate system is transformed so that the required engineering constants can be evaluated. Effective properties are computed for the materials with square and skew arrayed circular holes, and its accuracy is examined.

• 생물환경조절학회지
• /
• 제7권3호
• /
• pp.259-267
• /
• 1998

하우스 밀감의 품질을 향상시키고자 궁천조생을 공시하고 중간단수후 10일 후에 유공흑색필름, 부직포, 타이백을 수관하부에 멀칭하고 품질조사를 하였다. 하우스에서 멀칭재료에 따른 산란광의 변화는 타이백, 부직포, 흑색유공필름, 무처리 순으로 증가되는 경향이었다. 2. 과피의 착색도 a는 타이백 처리구가 무처리에 비해 6.39 높아서 타이백 멀칭효과가 매우 높았으며 a/b도 이와 유사한 경향을 나타내었으나 유의차는 없었다. 과즙의 glucose 함량은 무처리에 비해 멀칭처리구에서 많은 경향이었으나 처리간에 유의차가 없었고 fructose 함량은 무처리에 비해 타이백 멀칭구에서 0.31%/mL가 많았다. Sucrose 함량에도 차이가 있어서 무처리에 비해 타이백 멀칭구에서 1.36%/mL가 증가되었으며, 총 당도 sucrose와 유사한 경향이었다. 당은 타이백 멀칭구에서 12.4 $^{\circ}$Brix, 무처리에서 11.5 $_{\circ}$ Brix로 타이백 멀칭구가 무처리에 비해 0.9 $^{\circ}$Brix증가되어 타이백 멀칭효과가 현저하였음을 실증하였으나 산도는 멀칭처리 구간에 큰 차이를 나타내지 않았다

• Archives of Plastic Surgery
• /
• 제44권1호
• /
• pp.76-79
• /
• 2017

Necrotizing fasciitis (NF) is an aggressive soft-tissue infection involving the deep fascia and is characterized by extensive deterioration of the surrounding tissue. Immediate diagnosis and intensive treatment, including debridement and systemic antibiotics, represent the most important factors influencing the survival of NF patients. In this report, we present a case of NF in the abdomen due to an infection caused by a perforated small bowel after abdominal liposuction. It was successfully treated using negative-pressure wound therapy, in which a silicone sheet functioned as a barrier between the sponge and internal organs to protect the small bowel.

• Journal of the Optical Society of Korea
• /
• 제16권4호
• /
• pp.331-335
• /
• 2012

A miniaturized laser beam transmitter, in which a visible laser module at ${\lambda}$=650 nm is precisely stacked upon an infrared (IR) module at ${\lambda}$=905 nm, has been proposed and constructed to provide an IR collimated beam in conjunction with a collinear monitoring visible beam. In particular, the IR beam is selectively dispersed through a perforated sheet diffuser, so as to create a rapidly diverging close-range beam in addition to a highly defined long-range beam simultaneously. The complementary close-range beam plays a role in mitigating the blind region in the vicinity of the transmitter, which is inevitably missed by the main long-range beam, thereby uniformly extending the transmitter's effective trajectory that is sensed by a receiver. The proposed transmitter was designed through numerical simulations and then fabricated by incorporating a diffuser sheet, perforated with an aperture of 2 mm. For the manufactured transmitter, the IR long-range beam was observed to have divergences of ~2.3 and 1.6 mrad in the fast and slow axes, respectively, while the short-range beam yielded a divergence of ~24 mrad. The angular alignment between the long-range IR and visible beams was as accurate as ~0.5 mrad. According to an outdoor feasibility test involving a receiver, the combination of the IR long- and short-range beams was proven to achieve a nearly uniform trajectory over a distance ranging up to ~600 m, with an average detectable cross-section of ${\sim}60{\times}80cm^2$.

• Journal of the Optical Society of Korea
• /
• 제17권6호
• /
• pp.486-490
• /
• 2013

A portable infrared laser transmitter delivering a highly uniform detectable beam was demonstrated. It incorporates a flexible beam shaper, comprising a perforated diffuser sheet in conjunction with a pinhole. The beam shaper plays the prominent role of flexibly tailoring the incoming light via both scattering and diffraction, in order to equalize the effective beam width over a long distance. The intensity profile of a generated beam was practically observed, demonstrating that a substantially uniform beam of 70-cm width was achieved for a given threshold detection level, with an average deviation of 6% over a range of 600 m.