• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.850-853
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• 2008

In the motorized retractor of the smart seat belt system, anti-overload clutch is a very important element to prevent the excessive belt tensional force. Anti-overload clutch is the essential device to protect drivers from chest damage by the excessive belt tension. It generates slipping motion under excessive webbing moment and the belt tensional force is limited below critical value. In this study, slipping mechanism in the antioverload clutch is investigated by analysis and experiment. On the prototype model, finite element analysis is performed to identify the slipping condition and to determine the critical load. Analysis result is compared with the experimental result and the validity of the analysis model is verified. The purpose of the study is to provide the analytical background for the systematic design of the anti-overload clutch mechanism.

• 한국자동차공학회논문집
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• 제5권6호
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• pp.202-214
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• 1997

In automotive industries, one of major issues is the shifting shock, which is brought out when two clutches are engaged in an automatic transmission. The engagement and disengagement if two clutches means the variation of the D.O.F(degree of freedom) of system. Therefore to analyze the shifting performance, the variation of D.O.F should be considered in detail. Generally, the programs for analyzing the shifting transients have been developed as the problem-dependent codes because the artificial maris were usually used to indicate the change of shifting phase. To develop a software applicable to a general mechanism of transmissions, a self-determining algorithm of D.O.F must be applied. Through the experiences for the last several years, a generalized analysis software of shifting mechanism(so called by POTAS-MSM Version 2.0) has been developed. In this study, some major ideas of the software and the concept for the analysis of shifting characteristics are presented. In addition to that, this paper shows how to self -determine D.O.F of he multi-slipping systems using the stick-slip criterion on a single slipping mechanism. By using this software, the shifting characteristics of a vehicle are analyzed and compared with the experimental results.

• 한국지반공학회지:지반
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• 제12권3호
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• pp.35-48
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• 1996

보강토구조물은 흙과 보강재 사이에 큰 변형이 발생하며 보강토구조물의 파괴양상도 보강재의 미끄러짐이나 변형에 의해 지배되며, 때때로 보강재의 재료의 파괴보다는 미끄러짐에 의해 보강토구조물이 파괴되므로 큰변형이 발생하는 흙-보강재의 모델링이 필요하다. 고형 및 액체폐기물 매립장에 쓰이는 라인너 시스템은 매립장의 경사와 쓰레기하중에 의해 큰 변형이 발생하게 된다. 이러한 큰 변형의 문제는 기존의 접촉요소로써 모델링하는데 많은 제약 이 따른다. 본 논문에서는 이러한 흙과 토목섬유보강사이의 큰 만행을 모델링할 수 있는 접촉은소를 제안하였으며, 그 이론과 그 모델의 적용성에 대하여 논하였다.

• Bulletin of the Korean Chemical Society
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• 제23권9호
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• pp.1347-1350
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• 2002

• Geomechanics and Engineering
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• 제14권4호
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• pp.337-344
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• 2018

The study of the mining effect influenced by a normal fault has great significance concerning the prediction and prevention of fault rock burst. According to the occurrence condition of a normal fault, the stress evolution of the working face and fault plane, the movement characteristics of overlying strata, and the law of fault slipping when the working face advances from footwall to hanging wall are studied utilizing UDEC numerical simulation. Then the inducing-mechanism of fault rock burst is revealed. Results show that in pre-mining, the in situ stress distribution of two fault walls in the fault-affected zone is notably different. When the working face mines in the footwall, the abutment stress distributes in a "double peak" pattern. The ratio of shear stress to normal stress and the fault slipping have the obvious spatial and temporal characteristics because they vary gradually from the higher layer to the lower one orderly. The variation of roof subsidence is in S-shape which includes slow deformation, violent slipping, deformation induced by the hanging wall strata rotation, and movement stability. The simulation results are verified via several engineering cases of fault rock burst. Moreover, it can provide a reference for prevention and control of rock burst in a fault-affected zone under similar conditions.

• Fibers and Polymers
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• 제7권3호
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• pp.310-316
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• 2006

In this article, an attempt has been made to explain the failure mechanism of spun yams. The mechanism includes the aspects of generation and distribution of forces on a fibre under the tensile loading of a yam, the free body diagram of forces, the conditions for gripping and slipping of a fibre, and the initiation, propagation, and ultimate yam rupture in its weakest link. A simple mathematical model for the tenacity of spun yams has been proposed. The model is based on the translation of fibre bundle tenacity into the yam tenacity.

• 대한기계학회논문집A
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• 제20권6호
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• pp.1762-1772
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• 1996

The main objective of this study is to develop a gripper mechanixm that can be employed for assembly and removal tasks of a nozzle-dam of steam genetator in the process of the nuclear reactor maintenances. Brief description of the open-close thpe gripper mechanism, its position analysis, and its kinematic analysis are given. The optimal design of the gripper mechanism with and without slipping on its two gipping surfaces is considered. As an optimal design index, the ratio of the actuator force of prismatic cylinder to gripping load is proposed. Then, based on this index the oiptimal design is carried out to identify values of optimal design parameters for the gripper dechanism.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.525-530
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• 1995

The main objective of this study is to develop a gripper mechanism that can be employed for assembly and removal tasks of a nozzle-dam of steam gererator which is one of the nuclear reactor maintenance process. Brief description of the open-close type gripper mechanism, its postion analysis, and its kinematic amalysis are given. The optimal design of the gripper mechanism with slipping on its two gripping surfaces is considered. As an optimaldesign index, the ratio of the actuator force of prismatic cylinder to gripping load is proposed. Then, based on this index the optimal design synthesis is careied out to identify values of optimal design parameters for the gripper mechanism.

• 드라이브 ㆍ 컨트롤
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• 제18권1호
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• pp.31-38
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• 2021

This study presents a new principle for driving the robot aimed at reducing the position error for the boresonic examination of turbine rotor. The conventional method of inspection is performed by installing manipulator onto the flange of the turbine rotor and connecting a pipe, which is then being pushed into the bore. The longer the pipe gets, the greater sagging and distortion appear, making it difficult for the ultrasonic sensor to contact with the internal surface of the bore. A pneumatic pressure will ensure the front or rear feet of the robot in close contact with the inner wall to prevent slipping, while the ball screw on the body of the robot will rotate to drive it in the axial direction. The compression force required for tight contact was calculated in the form of a three-point support, and a static structural simulation analysis was performed by designing and modeling the robot mechanism. The driving performance and ultrasonic detection ability have been tested by fabricating the robot, the test piece for ultrasonic calibration and the transparent mock-up for robot demonstration. The tests have confirmed that no slipping occurs at a certain pneumatic pressure or over.

• 한국인터넷방송통신학회논문지
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• 제20권5호
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• pp.79-88
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• 2020

본 연구에서는 태양광 패널 청소 로봇이 진공 패드 압력을 이용하여 경사진 패널 위를 미끄러짐 없이 효율적으로 주행하는 방법을 제안한다. 이 방법에서는 로봇을 경사로 패널에 고정시키기 위해 로봇 발에 부착된 고무 패드의 압력을 진공으로 만들게 된다. 구동 방식으로 Linkage 매커니즘을 적용하여 미끄러짐을 방지함과 동시에 중량을 감소하여 소모전력을 낮추는 방법을 제안하였다. 로봇의 안전한 구동을 위하여 솔레노이드 밸브, 근접 센서, 엔코더를 사용하여 로봇의 움직임을 감지하며, 주행할 때 고무 패드의 압력을 제어하여 안전한 경사로 주행을 가능하게 하였다. 로봇의 전진 동작을 위하여 다중의 솔레노이드 밸브들의 동작 시퀀스를 완성하여 양쪽 발에 부착된 6개의 진공패드가 진공 및 대기압을 정확하게 형성 할수 있도록 제어하여 이동 중 미끄러짐 없이 전진할 수 있게 하였다. 마지막으로 주행 및 회전 실험을 통해 36도의 태양광 패널에서 직진 및 회전 동작을 수행할 수 있음을 확인하였다.