• Title/Summary/Keyword: Openings

Search Result 773, Processing Time 0.027 seconds

Assessment of Clothing Ventilation through Openings (개구부를 통한 의복의 환기 양상 평가)

  • 추미선
    • The Research Journal of the Costume Culture
    • /
    • v.8 no.5
    • /
    • pp.660-667
    • /
    • 2000
  • Clothing ventilation was investigated using a manikin wearing an impermeable overall under an isothermal condition, in which the ventilation occurred only through the openings. The ventilation volume was estimated by both microenvironment volume and ventilation rate, where, the microenvironment volume was measured by an air subsitution method and the ventilation rate by a trace gas method. Microenvironment volume of the experimental garment was about 21.0 liters. Even though it was certainly affected by the distance from the opening, the ventilation rate was more significantly influenced by the opening area and the shape of air layer in the clothing. The volume of air exchange in the clothing microenvironment was affected greatly by the microenvironment volume and the opening area, and it was different for each part of the body with bigger air exchange volume in the microenvironment of the leg as compared to that of the arm.

  • PDF

A Structural Analysis of Underground Openings in Discontinuous Rock Masses (불연속면의 영향을 고려한 지하암반공동의 구조해석)

  • 김선훈;최규섭;김해홍;김진웅
    • Computational Structural Engineering
    • /
    • v.4 no.4
    • /
    • pp.117-124
    • /
    • 1991
  • In order to predict properly the effects of ground motion associated with earthquakes on underground radioactive waste disposal facilities, an understanding of the structural behavior of an underground opening in discontinuous rock masses subjected to dynamic loadings is essential. This paper includes literature review on computational models for discontinuous rock masses and on mathematical models for the structural analysis of underground opening. Then, structural analyses of underground openings using the distinct element computer program written for the static and dynamic analysis of discontinuous rock masses have been performed.

  • PDF

A Study on the Protection of Smoke Control Performance in Building Enclosure to Prevent the Expansion of Smoke in Fire (화재시 연기확대 방지를 위한 건축물 구획공간에서의 방연성능 확보에 관한 조사 연구)

  • Jin, Seung-Hyeon;Kim, Hye-Won;Lee, Byeong-Heun;Kwon, Young-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2019.05a
    • /
    • pp.91-92
    • /
    • 2019
  • In case of fire in a compartmentalized building area, a number of casualties are caused by smoke production. Accordingly, openings, penetrations and joints in compartmentalized spaces should be secured not only for fire resistance but also for smoke-proofing. However, domestic test regulations stipulate test methods for refractory performance of penetrations and joints, but do not specify separate deferral performance. In the case of openings, the test for the smoke performance exists at room temperature, but the smoke performance at high temperature is not secured, so countermeasures are needed.

  • PDF

Study on the Five Fluids (오액(五液)에 관한 연구(硏究))

  • An, Jong Eun;Kang, Jung Soo
    • Journal of Haehwa Medicine
    • /
    • v.12 no.1
    • /
    • pp.71-78
    • /
    • 2003
  • "Jinaik(津液)" is essential nutritious body fluid for human to be alive, and it can be divided various kinds according to it's location, character, and function. Five Fluids -sweat, snivel(mucus), slobber(saliva), tear, spittle(saliva)- are kinds of "Jinaik(津液)", and all of them belong to kidney. They are also related with five organs, such as sweat belongs to heart, snivel(mucus) belongs to lung, slobber(saliva) belongs to spleen, tear belongs to liver, spittle(saliva) belongs to kidney. We can find out five organs' physiological and pathological conditions by means of observations on the Five Fluids. Five organs' function comes out upper seven openings -two eyes two ears, nose, mouth and tongue. The Five Fluids provide all the nutrition upper seven openings need, so they can help for human to hear, see, smell, and taste properly.

  • PDF

Simplified equations for Vierendeel design calculations of composite beams with web openings

  • Panedpojaman, Pattamad
    • Steel and Composite Structures
    • /
    • v.27 no.4
    • /
    • pp.401-416
    • /
    • 2018
  • Composite beams with web openings are vulnerable to Vierendeel bending failure. The available methods provide quite conservative estimates of Vierendeel bending resistance. An alternative design method to compute the resistance was proposed in this study, based on quadratic nonlinear interactions of normalized shear force, axial force and Vierendeel bending moment. The interactions of the top and bottom Tee section must satisfy mutual conditions to prevent the Vierendeel failure. The normalized shear force and Vierendeel bending moment of the composite part were used instead in the top Tee interaction. The top Tee axial force was computed based on force equilibrium. Based on a rigid-plastic model, the composite resistance is estimated using an effective slab width of the vertical shear resistance. On using the proposed method, nonlinear reductions due to shear loads and axial forces are not required, in contrast to prior methods. The proposed method was validated against experiments from literature. The method limitations and accuracy as well as the Vierendeel behavior were investigated by finite element simulations, with varied composite beam parameters. The proposed design loads are less conservative than earlier estimates and deviate less from the simulations.

A numerical study on behavior of CFRP strengthened shear wall with opening

  • Behfarnia, Kiachehr;Shirneshan, Ahmadreza
    • Computers and Concrete
    • /
    • v.19 no.2
    • /
    • pp.179-189
    • /
    • 2017
  • Concrete shear walls are one of the major structural lateral resisting systems in buildings. In some cases, due to the change in the occupancy of the structure or functional requirements like architectural and even mechanical ones, openings need to be provided and installed in structural walls after their construction. Providing these openings may significantly influence the structural behavior of the constructed wall. This paper considers the results of a nonlinear finite element analysis of shear walls with opening strengthened by carbon fiber reinforced polymer (CFRP) strips with different configurations. Details of bond-slip constitutive model of link elements to simulate the connections of FRP strips to concrete surface is presented. The proposed model in this research has been validated using experimental results available in the literature. The results indicated that the proposed configuration of CFRP strips significantly improved the lateral resistance and deformation capacity of the shear walls with opening.

Perforated shear connectors

  • Machacek, Josef;Studnicka, Jiri
    • Steel and Composite Structures
    • /
    • v.2 no.1
    • /
    • pp.51-66
    • /
    • 2002
  • Perforated shear connectors currently used in composite steel and concrete structures are described and evaluated. Modifications of the perforated connector suitable for common use injavascript:confirm_mark('abe', '1'); civil and bridge engineering are proposed. The connectors were tested in laboratories of CTU Prague for shear load capacity. Push tests of connectors with 32 mm openings and with 60 mm openings, both in normal and lightweight concrete of different strength characteristics and with different transverse reinforcement, were carried out. The experimental study also dealt with the connector height and parallel arrangement of two connectors and their influence on shear resistance. While extensive tests with static loading were carried out, fatigue tests under repeated loading are still in progress. After statistical evaluation of the experimental results and comparisons with other available data the authors developed reasonable shear resistance formulas for all proposed arrangements.

A Study on Smoke Movement by Using Large Eddy Simulation I. Smoke Control Systems and Extraction Flowrate (대와류모사를 이용한 연기이동의 연구 I. 제연방식과 배기풍량)

  • 박외철
    • Journal of the Korean Society of Safety
    • /
    • v.18 no.2
    • /
    • pp.40-45
    • /
    • 2003
  • To evaluate the smoke control systems, the large eddy simulation turbulence model based Fire Dynamics Simulate was applied to a 2m $\times$ 2m $\times$ 2.4m room with an opening. The smoke removal rate was investigated for three different smoke control systems: ventilation, extraction and pressurization. When the opening was closed, the smoke removal rates of the smoke control systems were almost the same as expected. The pressurization system showed a lower smoke removal rate compared with the other two smoke control systems for the room with the opening, and hence the pressurization system might not be efficient for a place with large openings. It was shown that the lower extraction flowrate is, the longer time the ventilation system requires to remove smoke. From these results, the ventilation system is recommended for subway stations where several large openings exist.

Design Equation of Reinforced Concrete Walls for Opening Configurations (개구부 형상을 고려한 철근콘크리트 벽체의 설계식 제안)

  • Lee, Dong-Jun;Oh, Soon-Taek
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.14 no.3
    • /
    • pp.131-137
    • /
    • 2010
  • 12 trial-scale wall panels are tested and evaluated to investigate the ultimate load capacity of axially loaded concrete walls with various opening configurations. The experimental tests have been undertaken to obtain data for the modification of existing equations. A new design equation has been generated using the precise test data and it incorporates the unique length factors. This new design equation for concrete walls with openings is then compared with existing code formulae.

An approach for failure analysis of composite bridge deck systems with openings

  • Zhao, Lei;Karbhari, Vistasp M.
    • Structural Engineering and Mechanics
    • /
    • v.20 no.1
    • /
    • pp.123-141
    • /
    • 2005
  • Design details pertaining to the connection between some recently developed fiber reinforced polymer (FRP) composite deck systems and the supporting girders require openings through cells of the deck. This significantly changes the stress distribution in these components. As a result, the conventional assumptions that deck designs are controlled by their stiffness, and not strength, needs a closer examination. This paper proposes an analytical method to investigate the stress states and failure mechanisms using a type of "global-local" modeling perspective, incorporating classical lamination theory and first ply failure criterion with use of appropriate stress concentration factors around the cutouts. The use of a "smeared-stress" approach is presented as a potential means of simplifying certain FRP specific complexities, while still enabling prediction of overall failure.