• Title/Summary/Keyword: load pressure distribution

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Fluctuating wind loads across gable-end buildings with planar and curved roofs

  • Ginger, J.D.
    • Wind and Structures
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    • v.7 no.6
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    • pp.359-372
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    • 2004
  • Wind tunnel model studies were carried out to determine the wind load distribution on tributary areas near the gable-end of large, low-rise buildings with high pitch planar and curved roof shapes. Background pressure fluctuations on each tributary area are described by a series of uncorrelated modes given by the eigenvectors of the force covariance matrix. Analysis of eigenvalues shows that the dominant first mode contributes around 40% to the fluctuating pressures, and the eigenvector mode-shape generally follows the mean pressure distribution. The first mode contributes significantly to the fluctuating load effect, when its influence line is similar to the mode-shape. For such cases, the effective static pressure distribution closely follows the mean pressure distribution on the tributary area, and the quasi-static method would provide a good estimate of peak load effects.

An Experimental Study on the Pressure and Temperature Distribution in a Plain Journal Bearing (저어널베어링의 압력 및 온도분포에 관한 실험적 연구)

  • 신영재;김경웅
    • Tribology and Lubricants
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    • v.4 no.1
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    • pp.69-73
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    • 1988
  • The effects of journal speed and bearing load on pressure distribution and the temperature distribution of bearing surface are investigated experimentally. The journal bearing which has 219.94mm diameter, length-to-diameter ratio of L/D=0.8 and clearance ratio of 0.004 is used. Journal has a built-in pressure transducer for the measurement of pressure distribution in the mid plane of bearing. Bearing surface temperatures are measured at 60 points. The bearing load is varied from 300 N to 5900 N and journal speed from 300 rpm to 2500 rpm. As the load is increased under constant speed, the location of maximum pressure moves to the site of minimum film thickness, and maximum pressure and absolute value of minimum pressure are increased. The temperature distribution in vicinity of oil inlet shows that heated lubricant's carry-over exists around the oil inlet.

Investigation of the body distribution of load pressure and virtual wear design of short pants harnesses in flying condition (플라잉 상태에서 바지형태의 하네스에 대한 하중압력 분포 측정 및 가상착의 적용)

  • Kwon, MiYeon
    • Journal of the Korea Fashion and Costume Design Association
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    • v.23 no.3
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    • pp.11-21
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    • 2021
  • Virtual reality is currently mainly used in games, but is starting to be applied as a variety of media fields, such as broadcasting and film. Virtual reality provides more fun than reality, and can provide new experiences in areas that cannot be experienced in reality due to the constraints of time, space, and environment. In particular, as the social non-contact arena has increased due to COVID-19, it is being applied to education, health, and medical industries. The contents are further expanding into design and military fields. Therefore, the purpose of this study was to observe the change in distribution of load and pressure felt by the body in the flying state while wearing a short pants harness, which are mainly used in the game and entertainment industry. In the experiment, the average pressure in the flying state was measured by attaching a pressure sensor to the back and front of a human mannequin. As a result, it was confirmed that the load concentrated on the waist in the flying state was 44 N, with a pressure of 1353 kPa. The pressure distribution was concentrated in front of the center of gravity, and was measured was at 98% by the pressure sensors, with an average pressure value of approximately 15 kPa, and a pressure value of approximately 12 kPa at the back, which was measured at 67% by the pressure sensor. The results of the load and pressure distribution measurement are presented as fundamental data to improve the wearability and comfort of harnesses in the future, and are compared to actual measured pressure values by analyzing the clothing pressure in flight through virtual wear of harnesses through the CLO 3D program.

The Effects of Friction on the Contact Area and the Distribution of Contact Pressure (접촉 면적과 접촉면 압력분포에 대한 마찰의 영향)

  • 이문주;조용주
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.11a
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    • pp.193-199
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    • 1999
  • In the 3-Dimensional contact of the smooth spheres, the effects of friction on the contact area and the distribution of contact pressure was studied numerically. The contact area and pressure distribution was evaluated for the only normal load and for the case of a normal load in the presence of a tangential traction. To do this work, the technique of simple discretization using the load . displacement relationship for a uniformly distributed load of a rectangular patch was used.

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Investigation of the body distribution of load pressure and virtual wear design according to the corset type harness (코르셋 타입 하네스의 신체 하중압력 분포 측정 및 가상착의 적용)

  • Kwon, MiYeon;Choi, Sola;Kim, Juhea
    • Journal of the Korea Fashion and Costume Design Association
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    • v.23 no.3
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    • pp.1-10
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    • 2021
  • Harnesses are used in a variety of industries, such as rescue operations, medicine, and entertainment. However, conventional harnesses have problems as they are uncomfortable to wear and causes continuous pain. Therefore, in this study, the load and pressure applied to the body in the flying state when using a conventional harness were measured in real time and the distribution change was observed. Load and pressure were measured using a modified corset harness, a pressure sensor, and a human mannequin to measure the maximum and average pressure on the waist. As a result, it was confirmed that the load concentrated on the waist in the flying state was 104 N, and the pressure was applied to the left and right sides was 800 kPa or greater. The pressure distribution showed a pressure of 3-45 kPa in 73% in all measurable pressures. The results of the load and pressure distribution are presented as basic data for improving the wearability and reducing the discomfort of harnesses in the future, aid in the development of a harnesses that can minimize discomfort for various activities, and increase the concentration on experiential activities. In addition, using the CLO 3D program, which is a 3D virtual wearing system, a harness was put on a virtual model, and the compression level was checked and compared with the actual pressure distribution. As a result of comparing the measured pressure values in the flying state with the clothing pressure wearing the harness in the CLO 3D program, the total pressure value was found to be about 68% of the actual measured value. This helps develop a harness that can minimize discomfort during activities by predicting the load and pressure on the body by first applying new designs to a virtual wearing system during development. These new harness patterns can solve the problems of conventional harnesses.

Lubrication Effect of Slider Bearing with Round Embossed Surface According to Its Slider Slope (둥근 엠보싱 형상이 있는 슬라이더 베어링의 경사도에 따른 윤활효과)

  • Chin, DoHun;Yoon, MoonChul
    • Tribology and Lubricants
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    • v.30 no.5
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    • pp.284-290
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    • 2014
  • The influence of round embossed surface on slider bearing characteristics and its load carrying capacity is discussed for thin film effect of embossed slider bearing. For the numerical computation of lubrication parameters such as pressure, load capacity and shear stress that are normalized and a Reynolds equation is used for the analysis of embossed slider bearing characteristics. For this purpose, the finite difference method of central difference scheme is used in this study. In a slider bearing with embossed form, several simulation parameters such as pressure, load capacity and shear stress of the bearing can be obtained according to independent parameters such as the slope of the slider bearing and number of embossing in the upper slider. Also this results can be summarized and be stored in sequential data file for latter analysis. After all, their distribution of the pressure and shear stress parameters can be displayed and be analyzed easily by using the developed program with matlab GUI technique. The independent parameters such as a number of embossing and a slope of the embossed surface slider are used for discussing simulation parameters of pressure distribution, shear stress and load carrying capacity of the round embossing. These study results reported in this paper should be applied to the other shaped slider bearing with a rectangular embossed surface or rectangular waved surface.

A study on the equivalent static wind load estimation of large span roofs (대스팬 지붕구조물의 등가정적 풍하중 산정에 관한 연구)

  • Kim, Dae-Young;Kim, Ji-Young;Kim, Han-Young;Lee, Myung-Ho;Kim, Sang-Dae
    • 한국공간정보시스템학회:학술대회논문집
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    • 2004.05a
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    • pp.245-251
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    • 2004
  • This paper discuss the conditionally sampled actual wind pressure distributions causing peak quasi-static wind loads in the large span roofs using the wind pressures at many locations on dome models measured simultaneously in a wind tunnel. The actual extreme pressure distributions are compared itk load-response-correlation (LRC) method and the quasi-steady pressure distributions. Based on the results, the reason for the discrepancy in the LRC pressure distribution and the actual extreme pressure distribution are discussed. Futhermore, a brief discussion is made of the equivalent static wind load estimation for the large span roofs.

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Earth Pressure on a Rigid wall due to Loads Condition and Distance (상재하중의 크기와 이격거리에 따른 강성벽체의 토압분포)

  • Oh, Bun-Jin;Lee, Sang-Duk
    • Journal of the Korean Geotechnical Society
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    • v.26 no.12
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    • pp.51-60
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    • 2010
  • Earth pressure due to gravity generally increases linearly with the depth, but the distribution of earth pressure due to surface load depends on the loading condition, the ground condition, and the boundary condition. In this study, the earth pressure on a rigid wall due to the vertical surface load was measured in experiments. Rigid wall was built in the model test box, and it was filled with homogeneous sandy ground (width 30 cm, height 88 cm, length 110 cm). Rigid wall was composed of 8 segments, which were tested on the two load cells. In the tests, we observed the distribution of the earth pressure on the rigid wall depending on the vertical surface load and it's location. According to the test results, the lateral earth pressure due to the vertical surface load showed its maximum value at a constant depth and decreased with the depth, to the negligible value at the critical depth. The critical depth and the depth at which lateral earth pressure reaches its maximum were not decided by the magnitude of the vertical surface load. They were dependant on the distance from the rigid wall.

A Study on the Characteristic of Contact Pressure for CPB (Cold Pad Batch) Padder Roll Controlled by Hydraulic Single Cell (단일 유압 Cell로 제어되는 CPB(Cold Pad Batch)용 패더롤의 접촉압력 특성 연구)

  • Cho, Kyung-Chul;Lee, Eun-Ha;Jo, Soon-Ok;Park, Si-Woo;Hwang, Youn-Sung;Kim, Soo-Youn
    • Textile Coloration and Finishing
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    • v.29 no.2
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    • pp.86-96
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    • 2017
  • To make uniform pressure distributed over the contact surface was necessary to cold pad batch dyeing machine. In this study, to confirm characteristic of flexibility and the contact pressure distribution through experimental analysis of padder roll were controlled by hydraulic cell. When there were no load pressure only inner pressure, the value of displacement in the center of padder were greater than the end of the padder. The results of this study showed that the padder had the optimum value of inner pressure for uniform contact pressure distribution. Measuring the contact pressure in a padder system were driven by using a pre-scale film. Uniform contact pressure distribution of cell padder were a linearly with load pressure and inner pressure. When the load pressure was less than 8 tons, the inner pressure for the uniform contact pressure was 1~4 bar. The padder roll performance curves proposed in this study were available for practical production environments and various roll designs.

Wind load combinations and extreme pressure distributions on low-rise buildings

  • Tamura, Yukio;Kikuchi, Hirotoshi;Hibi, Kazuki
    • Wind and Structures
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    • v.3 no.4
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    • pp.279-289
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    • 2000
  • The main purpose of this paper is to demonstrate the necessity of considering wind load combinations even for low-rise buildings. It first discusses the overall quasi-static wind load effects and their combinations to be considered in structural design of low-rise buildings. It was found that the maximum torsional moment closely correlates with the maximum along-wind base shear. It was also found that the instantaneous pressure distribution causing the maximum along-wind base shear was quite similar to that causing the maximum torsional moment, and that this asymmetric pressure pattern simultaneously accompanies considerable across-wind and torsional components. Secondly, the actual wind pressure distributions causing maximum quasi-static internal forces in the structural frames are conditionally sampled and their typical pressure patterns are presented.