• 제목/요약/키워드: joint factor

검색결과 935건 처리시간 0.023초

탄소섬유와 L형강을 이용한 벽-슬래브 접합부의 보강성능 (Structural Performance of Seismic Resistance Capacity of Carbon Sheet-Angle Retrofitting Method in Wall-Slab Joint)

  • 노공기;박태원;박현수;정란
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.65-68
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    • 2004
  • In the seismical capacity evaluation for RC structure wall-slab joint is very important factor. Because lateral load is resistance element and gravity load resistance element are acted mutually in the wall-slab joint. In this paper, to improve the seismic capacity of the wall-slab joint in the existing wall type apartments experiment which improve and retrofit a seismic capacity by unequal angle bracing and carbon sheet attachment are carried out. These methods are also economic and simple in mitigating seismic hazard, improve earthquake-resistance performance, and reduce risk level of building occupants. From the experimental results, the change of strength, degration of stiffness, and energy dissipation are evaluated. It can be concluded that these methods are effective in improving the seismic performance.

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슬관절 전치환술 이후의 고유수용성 감각 변화 (Proprioception After Total Knee Replacement)

  • 김재헌
    • PNF and Movement
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    • 제9권1호
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    • pp.39-45
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    • 2011
  • Purpose : The purpose of this article was to review the literature on change of knee position sense after total knee replacement intervention in knee rehabilitation. Methods : This review outlines scientific findings regarding different literature data in knee rehabilitation, and discusses proprioceptive change of knee joints after total knee replacement intervention. Result : Severe pain and diminished joint sensation may precipitate degenerative changes of knees joint, and a strong association between decreased proprioception and function has been identified in elderly patients with knee osteoarthritis. Total knee replacement(TKR) of the knee joint are effective surgical procedures in osteoarthritis patients, resulting in decreased pain, and improved physical function and quality of life in patients. After total knee replacement, joint position sensation is partially recovered, which may improve functional stability of the knee, but aspects of physical functioning are not fully restored to preoperative status. Conclusions : Thus, recovery rate in proprioception after TKR also is considered to be important because it may be a significant risk factor in failure of total knee replacement and knee rehabilitation intervention.

Exposed Reinforced Concrete-Filled Steel Tubular (RCFST) column-base joint with high-strength

  • Mou, Ben;Wang, Zian;Qiao, Qiyun;Zhou, Wanqiu
    • Steel and Composite Structures
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    • 제44권1호
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    • pp.1-15
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    • 2022
  • The weld quality has always been an important factor affecting the development of exposed CFT column-base joint. In this paper, a new type of exposed RCFST column-base joint is proposed, in which the high strength steel bars (USD 685) are set through the column and reinforced concrete foundation without any base plate and anchor bolts. Three specimens, the varying axial force ratio (0, 0.25 and 0.5), were tested under cyclic loadings. In addition, the bending moment capacity, energy dissipation capacity and deformation capacity of column-base joints were clarified. The experimental results indicated that the axial force ratio increases the stiffness and the bending moment and improves the energy dissipation capacity of column-base joints. This is because a large axial force can limit the slip between steel tubular and infilled concrete effectively. The specimens show stable hysteresis behavior.

충전절리면의 미끄러짐특성에 관한 연구 (A Study on the Sliding Characteristics of Infilling-joint Surface)

  • 이정엽;박영목;김재석;구호본;백용
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 봄 학술발표회 논문집
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    • pp.499-502
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    • 2003
  • The purpose of this study is to understand the sliding characteristics of the infilling-joint surface using the new devised shear test apparatus with changeable slope for the original infilling materials and the infilling materials experienced cyclic freezing-thawing processes. Three types of the mother rock classified as the igneous rock, the metamorphic rock and the sedimentary rock and the infilling materials were collected for laboratory test. The cohesion according to the slope change of the rock joint shows large variation within ${\pm}$5 degrees but the internal friction angle shows appears the linear decreasing tendency. It is confirmed that the affecting factor of slope change of rock joint at the behavior of rock mass is larger than that of the infilling thickness. Test results show that the cohesion and the internal friction angle in 100 times of cyclic freezing-thawing processes are decreased about 50 percent compared with original one. A further study using various infillings materials would lead to a better understanding of the failure mechanism of rock mass by slope change of rock joint.

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Temporomandibular joint dislocation: experiences from Zaria, Nigeria

  • Agbara, Rowland;Fomete, Benjamin;Obiadazie, Athanasius Chukwudi;Idehen, Kelvin;Okeke, Uche
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제40권3호
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    • pp.111-116
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    • 2014
  • Objectives: Dislocation of the temporomandibular joint may occur for various reasons. Although different invasive methods have been advocated for its treatment, this study highlights the value of non-invasive treatment options even in chronic cases in a resource-poor environment. Materials and Methods: A seven-year retrospective analysis of all patients managed for temporomandibular joint dislocation in our department was undertaken. Patient demographics, risk factors associated with temporomandibular joint dislocation and treatment modalities were retrieved from patient records. Results: In all, 26 patients were managed over a seven-year period. Males accounted for 62% of the patients, and yawning was the most frequent etiological factor. Conservative treatment methods were used successfully in 86.4% of the patients managed. Two (66.7%) of the three patients who needed surgical treatment developed complications, while only one (5.3%) patient who was managed conservatively developed complications. Conclusion: Temporomandibular joint dislocation appears to be associated with male sex, middle age, yawning, and low socio-economic status, although these observed relationships were not statistically significant. Non-invasive methods remain an effective treatment option in this environment in view of the low socio-economic status of the patients affected.

A study on compressive strength of concrete in flexural regions of reinforced concrete beams using finite element analysis

  • Cho, Chang-Geun;Hotta, Hisato
    • Structural Engineering and Mechanics
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    • 제13권3호
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    • pp.313-328
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    • 2002
  • Based on the orthotropic hypoelasticity formulation, a triaxial constitutive model of concrete is proposed. To account for increasing ductility in high confinement of concrete, the ductility enhancement is considered using so called the strain enhancement factor. It is also developed a three-dimensional finite element model for reinforced concrete structural members based on the proposed constitutive law of concrete with the smeared crack approach. The concrete confinement effects due to the beam-column joint are investigated through numerical examples for simple beam and structural beam member. Concrete at compression fibers in the vicinity of beam-column joint behaves dominant not only by the uniaxial compressive state but also by the biaxial and triaxial compressive states. For the reason of the severe confinement of concrete in the beam-column joint, the flexural critical cross-section is observed at a small distance away from the beam-column joint. These observations should be utilized for the economic design when the concrete structural members are subjected to high confinement due to the influence of beam-column joint.

암석파괴역학에 의한 3차원 절리면의 진행성 파괴 모델 (A Three-Dimensional Progressive Failure Model for Joints Considering Fracture Mechanics and Subcritical Crack Growth in Rock)

  • 김치환
    • 터널과지하공간
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    • 제19권2호
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    • pp.86-94
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    • 2009
  • 암석파괴역학과 파괴인성(rock fracture toughness) 이하의 응력확대계수(stress intensity factor)에서 균열이 성장하는 현상을 이용하여 암석 절리면의 비선형 강도특성과, 시간의 경과에 따라 파괴가 진행되는 특성을 고려한 수치해석용 3차원 절리면 요소를 개발하였다. 이 절리면 요소를 사용하여 암석 절리면 전단시험을 수치해석으로 모사한 결과, 전단응력이 증가하고 시간이 경과함에 따라 절리면 사이에 연결된 절리면 내 접점(asperity in joint)에서 암석의 파괴인성보다 응력확대계수가 작음에도 불구하고 균열이 발생하였고 시간이 경과하면서 균열이 성장, 절리면 내 접점이 파괴되었다. 이와 같이 각각의 절리면 내 접점의 파괴에 따라 절리면의 강도는 감소하고, 절리면의 전단응력은 응력경화와 응력연화 후 잔류응력에 도달하는 비선형거동을 보이면서 시간의 경과에 따라 점진적으로 파괴되었다.

고관절 가동성 증진을 위한 고유수용성 신경근 촉진 스트레칭의 생체역학적 고찰 (A Biomechanical Study on the Hip Joint Flexibility Based on the Proprioceptive Neuromuscular Facilitation)

  • 장지홍
    • 한국정보전자통신기술학회논문지
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    • 제8권1호
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    • pp.65-69
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    • 2015
  • 작업치료에서 관절의 가동성은 치료 절차와 기간에 영향을 미치는 중요한 요소이다. 수동적 스트레칭과 능동적 스트레칭을 병행하는 고유수용성 신경근 촉진법이 고관절의 가동성에 미치는 영향과 주요 굽힘/폄근의 근전도 활성정도 바탕으로 고유수용성 신경근 촉진 스트레칭의 생체역학적 특징을 고찰하였다. 10명의 20대 학생을 대상으로 고유수용성 신경근 촉진 스트레칭을 실시한 결과 고관절의 가동성이 전담 보조자의 도움을 받았을 때, 평균 $18.9^{\circ}$ 증가하였고 넙다리네갈래근과 뒤넙다리근의 근전도의 활성 또한 고유수용기의 생체역학적 특징을 나타내었다.

뇌성마비 아동의 엉덩관절에 관한 연구 (A Study for Hip Joint in Children with Cerebral Palsy)

  • 오태영
    • 신경치료
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    • 제22권3호
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    • pp.43-48
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    • 2018
  • Purpose The purpose of this study is to identify the prevalence, risk factors, characteristics, and interventions of hip joint problems in children with cerebral palsy, and to be able to serve as leverage for early detection, prevention, and function recovery. Method The electronic journal site was searched by the search terms "cerebral palsy", "hip joint", "hip joint dislocation", we analyzed and descript the cited articles from domestic and foreign papers in Pubmed 9, Science Direct 7, and K RISS analysis and analysis. Results Children with cerebral palsy showed the different prevalence according to their disability type, severity, and functional level, and we knew that abnormal neuromuscular control, stiffness, and biomechanical changes could be risk factors. Migration Index, Acetabolum Index, Neck shaft angle using by radiography and passive ROM test, special tests were available for the diagnosis and evaluation of the hip joint. Combination of physical therapy and orthopedic surgery was very important intervention, and complementary alternative therapy, orthosis, and postural assistant are effective. Conclusion We suggested that early detection and prevention is the most important periodic examination and that a multidisciplinary approach is a major factor in intervention.

Assessment of pull-out behavior of tunnel-type anchorages under various joint conditions

  • Junyoung Ko;Hyunsung Lim;Seunghwan Seo;Moonkyung Chung
    • Geomechanics and Engineering
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    • 제36권1호
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    • pp.71-81
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    • 2024
  • This study analyzes the pull-out behavior of tunnel-type anchorage under various joint conditions, including joint direction, spacing, and position, using a finite element analysis. The validity of the numerical model was evaluated by comparing the results with a small-scaled model test, and the results of the numerical analysis and the small-scaled model test agree very well. The parametric study evaluated the quantitative effects of each influencing factor, such as joint direction, spacing, and position, on the behavior of tunnel-type anchorage using pull-out resistance-displacement curves. The study found that joint direction had a significant effect on the behavior of tunnel-type anchorage, and the pull-out resistance decreased as the displacement level increased from 0.002L to 0.006L (L: anchorage length). It was confirmed that the reduction in pull-out resistance increased as the number of joints in contact with the anchorage body increased and the spacing between the joints decreased. The pull-out behavior of tunnel-type anchorage was thus shown to be significantly influenced by the position and spacing of the rock joints. In addition, it is found that the number of joints through which the anchorage passes, the wider the area where the plastic point occurs, which leads to a decrease in the resistance of the anchorage.