• Title/Summary/Keyword: Opening force

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Reliability Analysis of Access Door Opening Force Measured with a Digital Force Gauge of a Pressurized Smoke Control Zone and Presentation of Optimum Conditions for the Opening Force (디지털 측정기로 측정된 급기가압 제연구역의 출입문 개방력에 대한 신뢰성 분석 및 최적 조건 제시)

  • Lee, Jae-Ou;Choi, Chung-Seog
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.1
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    • pp.468-473
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    • 2016
  • The aim of this study was to measure the opening force of an access door of a pressurized smoke control zone and verify the reliability of the opening force. For the access door opening force, the opening load of the access door was measured before and after pressurized air had entered the smoke control zone. The reliability of the measured values was verified using the Anderson Darling's statistical analysis method of the Minitab Program. Because the analyzed P values were greater than 0.05 except for some floors before and after the operation of the smoke control equipment, the opening force was found to have 95% reliability. The normal distribution of the measured values showed no relationship with the operation of the smoke control equipment and the precision of the force gauge was believed to be reliable. The major factors for the optimal design of the pressurized smoke control equipment include the precision and reliability of the force gauge, the correct posture of the measuring person, and the same conditions for access doors. Therefore, a digital force gauge is believed to be suitable for measuring the opening force of the access door of a pressurized smoke control zone. In addition, standardization of the posture of a measuring person, the setup of the initial opening force of an access door, etc., are major variables for effective measurements of the door opening force of an access door.

Shape Design of Hinge Stopper to Improve Refrigerator Door Opening Force (냉장고 도어 개방력 개선을 위한 힌지 스토퍼의 형상설계)

  • Seo, Ji-Hwan;Lee, Sanghoon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.7
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    • pp.66-71
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    • 2021
  • In this study, the shape design optimization of a refrigerator door hinge stopper was performed to reduce the discrepancy in the opening forces of the left and right doors of a double-door refrigerator. A finite element model was constructed and analyzed by quasi-static analyses to evaluate the structural performance of the door hinge stopper. The reaction moment calculated at the hinge axis was used as a measure of the door opening and closing forces. The design objective is to increase the door opening force by 50% while maintaining the door closing force and the maximum stress calculated in the body of the hinge stopper at the current level. A new design concept with a contacting slot was proposed to decouple the door closing and opening forces. Shape optimization was performed to determine the dimensions of the new design of the hinge stopper, and the rib pattern was determined by topological optimization to further increase the door opening force. It was observed that the new design met all design requirements.

Opening Spring Modeling of Current Circuit Breaker Mechanism with respect to Opening Speed using Energy Method (전류 차단기 메커니즘에서 에너지방법을 이용한 차단 속도에 따른 스프링 모델링)

  • Kwon, Byung-Hee
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.688-692
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    • 2000
  • This study proposed design parameters of opening spring of circuit breaker that cut off the over-current in order to protect the electric device about opening speed using the energy method. We simulated the opening kinetic energy, the potential energy of opening spring and the design parameters of opening spring with respect to opening speed of VCB (Vacuum Circuit Breaker)'s moving contactor which has 24kV 25kA break capacity. From the result of simulation the initial tensional force and the final tensional force of the opening spring chose 107kgf and 282kgf respectively. Through the dynamic analysis using ADAMS, We verified that the opening speed of moving contactor satisfied break capacity of VCB and analyzed opening dynamic characteristics of VCB such as the opening displacement, the opening velocity and the opening acceleration of moving contactor in time domain.

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Influences of seepage force and out-of-plane stress on cavity contracting and tunnel opening

  • Zou, Jin-Feng;Chen, Kai-Fu;Pan, Qiu-Jing
    • Geomechanics and Engineering
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    • v.13 no.6
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    • pp.907-928
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    • 2017
  • The effects of seepage force and out-of-plane stress on cavity contracting and tunnel opening was investigated in this study. The generalized Hoek-Brown (H-B) failure criterion and non-associated flow rule were adopted. Because of the complex solution of pore pressure in an arbitrary direction, only the pore pressure through the radial direction was assumed in this paper. In order to investigate the effect of out-of-plane stress and seepage force on the cavity contraction and circular tunnel opening, three cases of the out-of-plane stress being the minor, intermediate, or major principal stress are assumed separately. A method of plane strain problem is adopted to obtain the stress and strain for cavity contracting and circular tunnel opening for three cases, respectively, that incorporated the effects of seepage force. The proposed solutions were validated by the published results and the correction is verified. Several cases were analyzed, and parameter studies were conducted to highlight the effects of seepage force, H-B constants, and out-of-plane stress on stress, displacement, and plastic radius with the numerical method. The proposed method may be used to address the complex problems of cavity contraction and tunnel opening in rock mass.

Evaluation of Perceived Exertion and Satisfaction in Opening and Closing Tailgates of Sport Utility Vehicles (스포츠 유틸리티 차량의 테일게이트 개폐 불편도와 만족도 평가)

  • Son, Byungchang;Ryu, Taebeum
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.1
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    • pp.1-10
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    • 2017
  • The difficulties in opening and closing a sport utility vehicle (SUV) tailgate is important aspect of JD (James David) power's Initial Quality Survey (IQS) assessment, and affective quality has a big impact on the the success of thesedays products. The purpose of this study is to evaluate the perceived difficulty and satisfaction of customers by the opening and closing of the tailgate and to grasp the relationship between them and the opening and closing reaction force. The mechanical force required to open and close 42 domestic and overseas SUV tailgates was measured with the help of an auto company. In the experiment, 100 male drivers in their 20s to 50s evaluated perceived difficulty and satisfaction with opening and closing the tailgate. The results of the analysis showed that perceived difficulty and satisfaction were statistically different depending on the vehicle, but did not depend on the personal characteristics of the participants. The perceived difficulty and satisfaction regression model of tailgate opening and closing was developed by mechanical force variables and had a relatively high adjusted $R^2$ ranging from 0.62 to 0.73. The models showed that the the initial close and open force, the difference between initial and maximum close force and the difference between initial and auto-fall angle should be small for the low perceived exertion and high satisfaction. In addition, the correlation analysis between IQS score of tailages and perceived difficulty and satisfaction showed that the IQS scores were more related to the perceived difficulty and satisfaction of closing than those of opening. The results of the study will be helpful to design and test mechanical open and close structure of SUV tailgates.

Experimental Research of Window Air Tightness and Opening Force with Respect to Mohair Number, Clearance and Shortened Length (모헤어 개수, 틈새 길이 및 축소된 길이의 창문 기밀성 및 개폐력에 대한 실험적 연구)

  • Kim, Seung Jae;Park, Jong Jun;Kim, Young Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.30 no.4
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    • pp.195-203
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    • 2018
  • Mohair is widely used as an airtight material for filling the gap between a window frame and sash. The purpose of this study is to investigate infiltration rate and opening force of sliding windows according to the mohair installation conditions. Infiltration experimental apparatus was set up, and the experimental results were applied to windows to find a correlation between infiltration rates and opening forces. When 4 rows of mohair were installed, the infiltration rate increase became 27.1% per clearance length increase of 1 mm, and the infiltration rate decrease became 5.7% per shortened length increase of 0.1 mm. For 4 rows of mohair, the opening force decreased by 28.2% as the clearance increased by 1 mm, and it increased by 9.3% as the shortened length increased by 0.1 mm.

Analysis of Door Effort using 2D Model (2차원 모델을 이용한 도어 개폐력 해석)

  • 김창원;강성종
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.3
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    • pp.131-137
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    • 2003
  • Proper door effort, required force to open or close a vehicle door, is an essential door design factor for the safety of passengers and pedestrians. Section shape of the door checker arm is the most influential design parameter for achieving a door effort design target. In this research. an analysis procedure to predict door effort using a simplified plane strain finite element model wes investigated for two passenger cars, for which mechanism of checker systems were: different. The variation of checker arm force to be required during moving on arm in opening and closing direction was estimated through analysis, and the result was transformed to the door effort with respect to door opening angle by considering door characteristics. Also, the self·closing force due to door weight was theoretically calculated and added to the door effort from checker arm force. Finally the estimated results of door effort were compared with test results.

Study on the Analysis of Differential Pressure of the Access Door for a Smoke Control Zone and the Effectiveness of the Measurement Criteria of its Opening Force (제연구역 출입문의 차압 및 개방력 측정기준의 실효성 분석에 관한 연구)

  • Lee, Jae-Ou;Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.26 no.4
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    • pp.24-30
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    • 2012
  • The purpose of this study is to analyze the problem in measuring the differential pressure between the fire area and the neighboring smoke control zone as well as the opening force of a fire door and to present the actual values measured by an objective method. NFSC 501A specifies that the force necessary to open an access door when operating a smoke control system shall be less than 110 N. When the smoke control system does not operate in the space where it is installed, the door opening force can be measured by the test method in KS F 2805. However, when the smoke control system operates, additional opening force is required to overcome the force generated by the differential pressure between the fire area and smoke control room. Therefore, it can be seen that the method proposed by the standard has insufficient reliability. The analog measuring device and digital measuring device showed that the opening forces, $F_a$ and $F_d$, of the fully closed door before the smoke control system were 27.8 N and 27.4 N, respectively. When the door remained open by $5^{\circ}$, the opening forces, $F_a$ and $F_d$, were 33 N and 33.6 N, respectively. When the smoke control system operated and the door was fully closed, the door opening forces, $F_a$ and $F_d$, were 77.6 N and 76.0 N, respectively. Therefore, since the door opening forces are different from the criteria presented by KS F 2805, it is required to review the criteria appropriately.

An Experimental Study on the Inflation Characteristics of Parachute Canopies (낙하산 캐노피 전개특성에 관한 실험적 연구)

  • Oh, Se-Yoon;Kim, Chan-Ki;Lee, Jong-Geon;Ahn, Seung-Ki
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.30 no.7
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    • pp.11-19
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    • 2002
  • Inflating characteristics of the parachute canopies have been experimentally investigated with the objective of measuring the parachute opening parameters such as canopy filling time and the peak opening force using scaled parachute models. A device has been made and tested to eject a model parachute into a wind tunnel flow and to measure the drag force acting on it. The force-time histories and the peak opening force are obtained, and these comparative aerodynamic characteristics were analyzed and discussed, including the effect of forebody wake. The opening of the ringslot parachute model appeared to be faster than that of the available similar data by about 10~40%, and fair to good agreement was obtained for the reefed ribbon parachute.

A Simple Control Method for Opening a Door with Mobile Manipulator

  • Kang, Ju-Hyun;Hwang, Chang-Soon;Park, Gwi-Tae
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1593-1597
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    • 2003
  • The home service robot supports human beings by performing various kinds of works at home. This paper presents a simple control method for opening a door from the viewpoint of the mobile manipulation. The simulation shows various results of path planning and motion planning for opening a door. The joint trajectories were generated by the simulation system. In general, a six-axis force/torque sensor at an end-effector is needed in order to maintain the static equilibrium of the manipulator. But we show another method. From three components of applied forces which was directly obtained by the three-axis force sensor and three components of applied forces which was indirectly estimated by the joint-torque sensors, all of joint torques that will exactly balance forces at the end-effector in the static situation can be found. It is more practical method than using a six-axis force sensor in a wrist. Experimental results have shown that the opening a door can be realized more effectively from the suggested control method of mobile manipulation.

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