• Title/Summary/Keyword: opening

Search Result 6,351, Processing Time 0.03 seconds

An Experimental Study on Reinforcing Effectiveness of H-Shaped Steel Beams with Rectangular Web Openings (다공 H 형강보의 보강효과에 관한 실험적 연구)

  • Kim, Jin-Mu
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.3 no.3
    • /
    • pp.213-222
    • /
    • 1999
  • On condition that opening located at high shear strength position in H-shaped steel beams with web opening, beams are structurally to be frailed so necessity and efficiency of vertical reinforcement to add horizontal reinforcement already published ahead study. Up to the present study of web opening beams, limited one opening which located in comparatively small shear strength position. But frequently opening area is enlargement by necessity, so width of opening is larger by limit of depth or increasing number of opening. This study carry out experiment to make efficient reinforcing method about strength and deformation of steel beams with web openings. Parameters of this study are openings location, ratio of opening width within opening height and various reinforcing types.

  • PDF

Experimental-numerical study on the FRP-strengthened reinforced concrete beams with a web opening

  • Abdullah Rafiq Safiaa;Suryamani Behera;Rimen Jamatia;Rajesh Kumar;Subhajit Mondal
    • Advances in concrete construction
    • /
    • v.15 no.5
    • /
    • pp.321-331
    • /
    • 2023
  • The effect of fibre-reinforced polymer (FRP) strengthening on the behaviour of reinforced concrete (RC) beams with web openings is studied. It has been observed that the load-carrying capacity and deflection in the presence of an opening reduced by approximately 50% and 75%, respectively. Three-dimensional nonlinear finite models are first validated with the results obtained from experimental data. Thereafter, a series of parametric studies are conducted for the beam with an opening. In the study, it is observed that a square opening shape is critical in comparison to the elliptical and circular-shaped opening. The web opening located near the support is found to be critically compared to the opening in the middle of the beam. Given the critical opening shape situated at the critical location, the increase in FRP layers enhances the load-deformation behaviour of the FRP-wrapped RC beam. However, the load-deformation responses are not significantly improved beyond a certain threshold value of FRP layers.

A Study on Sewing Methods of the Joseon Period -Focusing on Reinforcing the Opening of Clothes- (조선시대 복식에 나타난 바느질기법에 대한 연구 I - 트임 보강을 중심으로 -)

  • Ku, Nam-Ok
    • Journal of the Korean Society of Costume
    • /
    • v.58 no.8
    • /
    • pp.120-136
    • /
    • 2008
  • This study examined sewing methods used to reinforce the opening of clothes of the Joseon period. Through the analysis of a total of 117 clothing items of the Joseon period, the following results were obtained. 1. Most costumes of the Joseon period had the opening. The purpose of the opening was to allow one to put on and take off a costume, act comfortably, and turn a costume Inside out. The opening was located on the Side, Conte. Back, fgwi(Side opening of pants), Wristband, Armhole, and Godae(the bark part of the collar). 2. As the opening tended to get easily worn out, it was often reinforced. The 1911owing three methods were used to reinforce the opening of clothing items of the Joseon period: a method to attach a cloth such as Dang, Binding, and Badae; a method using a variety of knots; and a method by sewing stitches such as a sort of cross stitch called Satteugi, Prick stitch, and Loop. 3. The most frequently used reinforcing method was the one that used a knot(34 items), followed by the one by sewing Satteugi(27 items), and the one using Dang(25items). The most frequently detected location of the opening was Side(59 items), followed by Agui(37 items), Wristband(19 items), and Center Back(13 items). 4. The reinforced opening made a costume more endurable and elastic, decorative and neat.

Helium-Air Exchange Flow Through Openings with Vertical Partitions (수직평판을 삽입한 개구부의 헬륨 및 공기 치환류)

  • 강태일
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.24 no.3
    • /
    • pp.79-87
    • /
    • 2000
  • This paper describes experimental investigations of helium-air exchange flow through openings with vertical partitions. Such exchange flows may occur following rupture accident of stand pipe in high temperature gas cooled reactor. Exchange flow rates are investigated experimentally by using partitioned opening and opening with extended partition to assess fluids interference of the exchange flow at the stand pipe rupture accident. A tests vessel with the two types of opening on top of test cylinder is used in the experiments. An estimation method of mass increment is developed and applied to measure the exchange flow rate. A technique of flow visualization by Mach-Zehnder interferometer is provided to recognize the exchange flows. Amplitude and progress of interference fringes of the flows are observed and used as a support in comparison with the exchange flow rates. Flow passages of upward flow of the helium and downward flow of the air for both two types of the opening are separated by inserted partition within the opening, but in the case of partitioned opening, unseparated flow is formed at the opening entrance and the two flows interface. The exchange flow rate for the partitioned opening is not greater than that of the opening with extended partition because of the fluids interference at the entrance of opening. Finally, the fluids interference at the opening entrance is found to be one of important factors on the helium-air exchange flow rate.

  • PDF

An Evaluation on the Effect of Reversed Plastic Zone on the Fatigue Crack Opening Behavior under 2-D Plane Stress (2차원 평면응력 상태에서 되풀이 소성역이 피로균열 열림 현상에 미치는 영향에 관한 연구)

  • Choi, Hyeon-Chang
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.29 no.8 s.239
    • /
    • pp.1078-1084
    • /
    • 2005
  • The relationship between fatigue crack opening behavior and the reversed plastic zone sizes is studied. An elastic-plastic finite element analysis (FEA) is performed to examine the opening behavior of fatigue crack, where the contact elements are used in the mesh of the track tip area. The smaller element size than reversed plastic zone size is used fer evaluating the distribution of reversed plastic zone. In the author's previous results the FEA could predict the crack opening level, which crack tip elements were in proportion to the theoretical reversed plastic zone size. It is found that the calculated reversed plastic zone size is related to the theoretical reversed plastic zone size and crack opening level. The calculated reversed plastic zone sizes are almost equal to the reversed plastic zone considering crack opening level obtained by experimental results. It can be possible to predict the crack opening level from the reversed plastic zone size calculated by finite element method. We find that the experimental crack opening levels correspond with the opening values of contact nodes on the calculated reversed plastic zone of finite element simulation.

Dental hygienists' perspective and coping measures towards medical market opening (의료시장 개방에 대한 치과위생사의 인식과 대응방안)

  • Jung, Gi-Ok;Kim, Ho-Sun
    • Journal of Korean society of Dental Hygiene
    • /
    • v.12 no.3
    • /
    • pp.503-511
    • /
    • 2012
  • Objectives : This research seeks to present the data needed for the development of coping strategy, following medical market opening by identifying dental hygienists' perspective and coping measures towards the opening. Methods : One hundred eighty-eight dental hygienists were targeted to identify their level of perception towards medical market opening, attitude towards medical market opening, question of whether they agree or not with the opening and reasons, and coping measures and benefits of the medical market opening. t-test, chi-square test and cross-tabulation analysis were used for the analysis Results : First, team leaders are more aware of the medical market opening and hold greater sense of crisis towards opening compared to the rank and file. Second, the reasons cited for agreeing with the medical market opening included improvement of medical services' quality and diversification of services. As for the reasons for disagreeing, they cited the increase medical expenses paid by public. Third, limitation of the hospital management technique was cited the most when it comes to the scope of Korean hospitals' management crisis, followed by the limitations of the diagnosis procedure, limitations of the medical services, limitations of the medical techniques and increase in the number of large hospitals, in the order cited. Fourth, team leaders perceive greater need to seek coping measures from the aspect of realizing medical insurance fee from the policy development, service and system level aspects when it comes to the coping measures depending on their ranks. Conclusions : Therefore, Dental Hygienist has a comparatively low awareness of medical market opening, coping measures need to be explored to cope with the medical market opening by ensuring the dissemination of accurate knowledge through the education on the fees for dental hygienist and seminars in relation to the medical market opening.

Analysis the case study of tower type apartment by opening types of building surface (탑상형 아파트의 외피개방유형에 따른 전기에너지 사용량 사례 분석)

  • Kim, Yu-Won;Lee, Hyun-Soo;Kim, Eun-Hye
    • Proceeding of Spring/Autumn Annual Conference of KHA
    • /
    • 2011.04a
    • /
    • pp.111-115
    • /
    • 2011
  • The purpose of this study was the analysis of electric energy consumption with the case study of tower type apartment's opening of building surface. We analyze the relationship between tower type apartment's opening of building surface and using electric energy consumption. The results of this study are: 1) The highest energy consumption of electric energy was on August without any influence of opening types of building surface. 2) Also, the south-west sides consumption of August was 848 kWh on Type B(one side opening) and it was the highest usage. 3) A house if facing west used more electricity than facing east when its opening of building surface's datum level is facing south. However, the house of facing east used more power than west when its opening of building surface's datum level is facing north. 4) When opening of building surface is facing on north-west or north-east, the opening of building surface's side of west and east used more electric power than north-west or north-east sides.

  • PDF

Finite Element Analysis of Fatigue Crack Closure under Plane Strain State (평면변형률 상태 하에서 유한요소해석을 이용한 균열닫힘 거동 예측 및 평가)

  • Lee, Hak-Joo;Song, Ji-Ho;Kang, Jae-Youn
    • Proceedings of the KSME Conference
    • /
    • 2004.11a
    • /
    • pp.202-207
    • /
    • 2004
  • An elastic-plastic finite element analysis of fatigue crack closure is performed for plane strain conditions. The stabilization behavior of crack opening level and the effect of mesh size on the crack opening stress are investigated. In order to obtain a stabilized crack opening level for plane strain conditions, the crack must be advanced through approximately four times the initial monotonic plastic zone. The crack opening load tends to increase with the decrease of mesh size. The mesh size nearly equal to the theoretical plane strain cyclic plastic zone size may provide reasonable numerical results comparable with experimental crack opening data. The crack opening behavior is influenced by the crack growth increment and discontinuous opening behavior is observed. A procedure to predict the most appropriate mesh size for different stress ratio is suggested. Crack opening loads predicted by the FE analysis based on the procedure suggested resulted in good agreement with experimental ones within the error of 5 %. Effect of the distance behind the crack tip on the crack opening load determined by the ASTM compliance offset method based on the load-displacement relation and by the rotational offset method based on the load-differential displacement relation is investigated. Optimal gage location and method to determine the crack opening load is suggested.

  • PDF

Effect of building volume and opening size on fluctuating internal pressures

  • Ginger, John D.;Holmes, John D.;Kopp, Gregory A.
    • Wind and Structures
    • /
    • v.11 no.5
    • /
    • pp.361-376
    • /
    • 2008
  • This paper considers internal pressure fluctuations for a range of building volumes and dominant wall opening areas. The study recognizes that the air flow in and out of the dominant opening in the envelope generates Helmholtz resonance, which can amplify the internal pressure fluctuations compared to the external pressure, at the opening. Numerical methods were used to estimate fluctuating standard deviation and peak (i.e. design) internal pressures from full-scale measured external pressures. The ratios of standard deviation and peak internal pressures to the external pressures at a dominant windward wall opening of area, AW are presented in terms of the non-dimensional opening size to volume parameter, $S^*=(a_s/\bar{U}_h)^2(A_W^{3/2}/V_{Ie})$ where $a_s$ is the speed of sound, $\bar{U}_h$ is the mean wind speed at the top of the building and $V_{Ie}$ is the effective internal volume. The standard deviation of internal pressure exceeds the external pressures at the opening, for $S^*$ greater than about 0.75, showing increasing amplification with increasing $S^*$. The peak internal pressure can be expected to exceed the peak external pressure at the opening by 10% to 50%, for $S^*$ greater than about 5. A dominant leeward wall opening also produces similar fluctuating internal pressure characteristics.