• Title/Summary/Keyword: Joint stability

Search Result 883, Processing Time 0.027 seconds

Structural Performance Evaluation of End-plate Connections According to Constructional Quality in P.E.B System (P.E.B 시스템에서 시공상태에 따른 엔드플레이트 접합부의 구조성능평가)

  • Lee, Eun-Taik
    • Journal of Korean Society of Steel Construction
    • /
    • v.24 no.4
    • /
    • pp.461-468
    • /
    • 2012
  • P.E.B (Pre-Engineering Building) system means an economical system, which designs and uses optimal section proportion of tapered members according to the magnitude of bending moment. However, it is hard to adjust the friction type bolted joint in the joint of tapered member in the P.E.B system. End-plate connection is mainly used in this system due to that difficulty. Because P.E.B system has end-plate vertical defacts by heat welding deformation, a gap between end-plates and rafter or rib can be observed. In this study, an examination of construction stability was throughly performed and analyzed by the investigation of permissible internal force of bolts in end-plate connections under the bending moment using the end-plate's initial connection-defect (gap).

The Effect of Form and Hardness of Outsoles on the Motion of the Lower Extremity Joints and on Foot Pressure during Gait (보행 시 신발의 아웃솔 형태가 하지 관절 운동과 발의 압력에 미치는 영향)

  • Kim, Eui-Hwan;Kim, Sung-Sup;Kwon, Moon-Seok;Wi, Ung-Ryang;Lim, Jung;Chung, Chae-Wook
    • Korean Journal of Applied Biomechanics
    • /
    • v.21 no.2
    • /
    • pp.223-230
    • /
    • 2011
  • The purpose of this study was to analysis the effect of form and hardness of outsoles on the motion of the lower extremity joints and on foot pressure during gait. The subjects were 15 women(mean age, $48.5{\pm}2.4$ years), who had no serious musculoskeletal, coordination, balance or joint/ligament problems within 1 year prior to the study. The pelvic tilt, joint angles at the lower extremities and the vertical ground reaction force(GRF) were compared during gait with 3 types of shoes (A, B, C) by using one-way repeated ANOVA(p<.05). During gait, the peak tilt angle and the range of motion(ROM) of the ankle and knee joints were found to be significantly different among the 3 types of shoes. The type C shoes showed a significantly lower mean second maximum vertical GRF than types A and B. The curved outsoles of type C shoes, which had a form and hardness different from those of A and B, was designed strategically for walking shoes to provide stability to the Additionally, type C induced the dispersion of eccentric pressure and made the center of pressure roll over to the center line of the foot.

Partial Discharge Detection and Statistic Value Calculation of Power Cable Using Data Acquisition System (데이터 취득 시스템을 이용한 전력케이블의 부분방전 검출과 통계량 계산)

  • 조경순
    • Journal of the Korea Computer Industry Society
    • /
    • v.3 no.12
    • /
    • pp.1651-1658
    • /
    • 2002
  • Recently power cable used generally in Korea, because installation is very simple and it has high stability. It confirms to the requirements of IEEE std. 404-1993 by factory testing, but many problems of insulated cable systems are caused by internal defects of the joint part which have to be mounted ensile. Especially, fault rates are arise from impurities or voids. A suitable solution for a monitoring of power cable during the after-laying test and service is partial discharge detection. The artificial defects between cable joint(EPR) and insulator(XLPE) interface are considered in this research to investigating the partial discharge characteristics. ${\varphi}$-q-n properties were detected using data acquisition system and Maximum charge($q_{max}$), repetition rate(${\={n}$), average charge(${\={q}$), Unbalance rate of ${\={n}$ and ${\={q}$ are calculated in order to analysis partial discharge properties quantitatively from this statistic value.

  • PDF

Design and Optimization of Active Transfemoral Prosthesis System (능동형 대퇴의지 시스템의 설계 및 최적화 연구)

  • Chung, J.H.;Lee, K.H.;Lee, C.H.
    • Journal of rehabilitation welfare engineering & assistive technology
    • /
    • v.8 no.4
    • /
    • pp.283-289
    • /
    • 2014
  • This paper presents a design and optimization of the fully-active transfemoral prosthesis leg system. As it has one degree of freedom in knee joint, this prosthesis leg can imitate the human's gait. The weight of system, which makes the users more comfortable due to less tiredness, and the knee joint torque to rise stability of the system are major factors of prosthesis leg system. Thus the mechanism of prosthesis changes from 3-linkage type to geared type. The sensorized foot is also designed to effectively determine human's gait by measuring deformation of the foot during gait. Topology optimization is carried out for the sensorized foot to remove its unnecessary weight. The safety of optimized foot is verified by carrying out finite element analysis.

  • PDF

A Case Study on Collapse Characteristics of Slope during Construction in the Chung-Cheong Area (시공 중 비탈면의 붕괴 특성에 대한 충청지역 사례연구)

  • Lee, Jundae;Bae, Wooseok
    • Journal of the Korean GEO-environmental Society
    • /
    • v.16 no.10
    • /
    • pp.23-32
    • /
    • 2015
  • Most studies on slope collapsed have focused on collapse cases that occur on stabilized slopes in public use. Few studies have been conducted on the collapse characteristics of slopes that occur during construction before stabilization of the slope. In this study, detailed investigation was conducted for 79 sites where slope collapse occurred during or immediately after construction in the Chungcheong region, and their geometrical characteristics, collapse characteristics, design and reinforcement methods were evaluated. As a result of this analysis, it was found that the Chungbuk (CB) area was marked by plane-type collapse and surface layer collapse whereas the Chungnam (CN) area was marked by surface layer collapse or loss of sedimentary rocks. Furthermore, the major collapse factors of the Chungbuk region were joint alternations (53%) and weathering (25%), and the blocking due to multidirectional joints and foliation was also an influencing factor. In the phyllite area, too, the development of joints (55%) was a major factor, but the geological characteristics (36%) of sedimentary rocks such as faults and coaly shale also had considerable effects. Therefore, the geological, climatic, and environment characteristics were found to have affected the stability of slopes.

A Study on the Deformation Modulus for Tunnel Displacement Assessment in Multi-Jointed Rock Mass (다중절리 암반지층에서의 터널변위 산정을 위한 변형계수에 관한 연구)

  • Son, Moorak;Lee, Wonki
    • Journal of the Korean GEO-environmental Society
    • /
    • v.18 no.5
    • /
    • pp.17-26
    • /
    • 2017
  • Tunnel excavation in jointed rock mass induces a displacement along tunnel excavation line and its assessment is very important to ensure the stability of tunnel and a demanded space. Tunnel displacement is directly related to the deformation modulus of ground and therefore it is essential to know the value of the parameter. However, most rock masses where tunnels are constructed are generally jointed and it is difficult to find out the deformation modulus of jointed rock mass simply based on an homogeneous isotropic elastic medium because the deformation modulus is highly affected by joint condition as well as rock type. Accordingly, this study carried out extensive numerical parametric studies to examine the variation of deformation modulus in different joint conditions and rock types under the condition of tunnel excavation. The study results were compared with existing empirical relationships and also shown in the chart of deformation modulus variation in different jointed rock mass conditions.

Stability Analysis of Rock Slope (암반절취사면의 안정해석)

  • Cho, Seong Seop;Kim, Yong Seong;Chee, In Taeg;Lee, Dal Won
    • Korean Journal of Agricultural Science
    • /
    • v.23 no.1
    • /
    • pp.1-12
    • /
    • 1996
  • To design the safe and rational rock slope, several rock slopes of roads in Kang-won area were analyzed, and the following results were obtained ; 1. The results were analyzed by stereographic projection at the rock slope that the joint was developed. All of the sloped which were designed by standard slope of rock was not considered that the joints were unstable. 2. The relation of rainfall and slope failure, as well as the danger of failure, was very high when the maximum hourly rainfall was larger than 20mm and when there was a 2-day cumulative rainfall that was larger than 200mm. 3. In the design of rock slope, operated by the stereographic projection considering discontinuity. If turn out unstable, it should be analyzed carefully using the limit equilibrium method. 4. In the design of rock slope, it is desirable to consider the discontinuity of rock(joint, bedding, fault).

  • PDF

The Spiral Taping Treatment on Temporomandibular Disorder in oral Medicine (구강내과영역에서 측두하악장애 환자의 Spiral Taping 치료)

  • Kim, Myung-Hee;Lee, Jeong-Hun
    • Journal of Oral Medicine and Pain
    • /
    • v.36 no.1
    • /
    • pp.65-70
    • /
    • 2011
  • The purpose of this study is introduce the spiral taping treatment on Temporomandibular Disorder in oral Medicine. The taping treatment is relatively simple and dosen't have any adverse effect, so it has high stability and superior effect of treatment. In this study, using the spiral taping treatment as one of the effective taping treatments, non-stretched tape was attatched to the muscles which set limit to the range of joint movement and cause pain to temporomandibular joint. With that treatment this study tried to make effective results of treatment of temporomandibular disorder. These results suggest spiral taping treatments contribute to the improvement of tempermandibular disorders. Further this study is needed for the confirmation of this effect of spiral taping treatments on temporomandibular disorders.

Analysis on the Behaviors of Precast Concrete Beam-Column Connections Subject to Cyclic Loading (반복하중을 받는 프리캐스트 콘크리트 건식 보-기둥 연결부의 거동분석)

  • Song, Hyung-Soo;Yu, Sung-Yong
    • Journal of the Korea Concrete Institute
    • /
    • v.18 no.4 s.94
    • /
    • pp.497-506
    • /
    • 2006
  • The precast concrete beam-column connectors for the high-rise office buildings were investigated experimentally in this study. The specimens of general precast beam-column connector which is used in a domestic site, specimen of DDC(dywidag ductile connectors) of Germany, and specimen of DDC with post-tensioning and modified DDC with post-tensioning were constructed and tested to verify the safety. The DDC with and without post-tensioning showed reliable joint strength and ductility but failed in critical inclined shear crackings at the column. The modified one showed better behaviors in tests because they did not show critical column crackings at failure. The use of prestressing did not helpful significantly to increase the strength and ductility of connectors but helpful only to develop self-centering behavior for stability.

The Surgical Treatment of Acromioclavicular Joint Dislocation using Modified Phemister and Modified Weaver-Dunn Operation (견봉쇄골 관절 탈구에서 Modified Phemister와 Modified Weaver-Dunn 술식을 이용한 수술적 치료)

  • Chun Churl-Hong;Lee Seong-Ho;Lee Byung-Chang;Cho Yong-Woo
    • Clinics in Shoulder and Elbow
    • /
    • v.1 no.2
    • /
    • pp.180-185
    • /
    • 1998
  • There has been considerable controversy as to the treatment method of dislocation of the acromioclavicular joint, so various operative treatment modalities have been suggested. We analyzed the results of 40 patients with acromio­clavicular dislocation, in whom twenty patients were treated by modified Phemister method and 20 patients by modified Weaver-Dunn method above follow-up two years. The purpose of this study was to compare the clinical results of two operative methods. According to Weitzman criteriae for clinical results, 12 cases were excellent, six cases good and two cases fair in modified Phemister method. But in modified Weaver-Dunn method, ten cases were excellent, eight cases good, one case fair and one case poor. In radiological result, coracoclavicular distance was measured at preoperative, postoperative and last follow-up period. The modified Phemister method was 6.lmm, 1.5mm and 2.4mm respectively, and the modified Weaver-Dunn method 7.8mm, 2.lmm and 2.5mm respectively. The complications were two cases of heterotopic ossification, one case of inadequate fixation and one case of K-wire breakage in modified Phemister method, and two cases of early fixation loss and one case of heterotopic ossification in modified Weaver-Dunn method. We obtained that the clinical, functional and radiological results showed no significant difference in two methods. The modified Phemister method was effective treatment for old patients in acute injuries due to short operation time and simple technique. The modified Weaver-Dunn method, as a reconstructive operation that reduces various complications for young and active male patients, was also good for getting the stability of coraco­clavicular ligament through clavicular bony union.

  • PDF