• Title/Summary/Keyword: Elastic joint

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A Simulation Study on the Stress Distribution of the Transplanting Part of Artificial Knee Joint due to Elastic Modulus (탄성계수에 따른 무릎 인공관절 이식 부품의 응력분포에 관한 시뮬레이션 연구)

  • Lee, J.H.;Hwang, G.W.;Cho, J.U.;Cheon, Seong S.
    • Composites Research
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    • v.28 no.3
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    • pp.89-93
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    • 2015
  • This study analyzes the transplanting parts used as the graft of artificial knee joint. The low elastic titanium alloy is applied to clear up the stress shield effect. The simulation analysis is carried about the stress distribution of the transplanting parts. The correlation with frame is inferred and investigated through the equivalent stress distribution of titanium alloy due to elastic modulus. The stress of the transplanting parts decreases as the elastic modulus decreases at the first time. It decreases greatly near the stress of 46 GPa and increases again. Because the stress happened at the transplanting parts decreases, more stress is applied on the frame. This phenomenon is the stress shield effect. The result of this study can be thought to be necessary to develop the safe design of composite material.

The Effect of Joint Taping and Muscle Taping on Dynamic Balance and Gait in Patents with Chronic Stroke (관절 테이핑과 근육 테이핑이 만성 뇌졸중 환자의 동적 균형과 보행에 미치는 영향)

  • Joo, Mincheol;Lee, Yangjin;Hwang, Junhyun;Kim, Seongryeol
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.2
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    • pp.77-84
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    • 2019
  • Purpose : Elastic taping is a therapeutic method, used for treatment of various musculoskeletal and neuromuscular deficits. However, there is limited evidence, of the effects of ankle elastic taping in neurologic patients. The purpose of this study, was to investigate the effect of elastic taping on gait, in the affected ankle area of chronic stroke patients. Methods : Subjects were randomized to receive 30 chronic stroke patients, who were 6 months old from the date of onset according to screening criteria. Group I showed ankle joint taping, and Group II had ankle muscle taping. Dynamic balance and temporal and spatial gait, were measured before taping application, and after 30 minutes of taping application. Results : Dynamic balance was measured using the Time up & Go test (TUG). There was statistically significant difference, between Group I and Group II (p<.05). There was no statistically significant difference, between Group I and Group II. Temporal and spatial gait were measured using GaitRite. In Group I, there was significant difference, before and after taping (p<.05). In Group II, there was no significant difference, before and after taping (p>.05). There was significant difference in Group I, between Group I and Group II (p<.05). Conclusion : Results suggest that intervention using elastic taping, may have a positive effect, on rehabilitation diversity and function in stroke patients. Based on this, it can be used for rehabilitation of stroke patients. Various studies on the application method, and effect of the application site as well as application time, should be continued with stroke patients.

Strength Evaluation on Sectional Members of Prefabricated Precast Concrete Arch with Reinforced Joint (보강된 이음부가 적용된 조립식 프리캐스트 콘크리트 아치의 단면 강도 평가)

  • Joo, Sanghoon;Chung, Chulhun;Bae, Jaehyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.5
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    • pp.1363-1372
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    • 2014
  • In the previous study, the structural performance of proposed precast concrete arch with reinforced joint was evaluated by structural experiment. In this paper, finite element analysis considering both material and contact nonlinearity was carried out on the specimens of the previous study. Based on the result of analysis and experiment, friction coefficient between concrete blocks was determined. To evaluate the strength of sectional member, elastic analysis was carried out on the arch using linear elastic analysis program. The section force was compared with the nominal strength of arch section. It was concluded that the maximum load of all the specimens exceed the nominal strength of arch section. Those results of the strength evaluation were similar to the results of structural experiments. Therefore, it is concluded that the elastic analysis and ultimate strength model can effectively evaluate the strength for the proposed precast concrete arch composed of concrete blocks and reinforced joint in design.

Load Transfer Behaviors near the Spliced Joint of the Fiber Metal Laminates (섬유금속적층판 연결접합 부위의 하중전달 거동 연구)

  • Choi, Heung-Soap;Roh, Hee-Seok;Jang, Yong-Hoon
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1388-1393
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    • 2003
  • In this study, analytic stress-displacement solutions are obtained by using a shear lag modeling constructed for the spliced joint area with a splicing gap filled with adhesive material of elastic modulus $E_{a}$ in the fiber metal laminate (FML) which is known to have excellent fatigue, corrosion and fire-flame resistant characteristics while with relatively low densities compared to the conventional aluminum alloys for lightweight structures.

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Correlation Between Joint Angular Displacement and Moment in the Human Foot (인체 족부관절의 각변위와 모멘트의 상관관계)

  • 김시열;신성휴;황지혜;최현기
    • Journal of Biomedical Engineering Research
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    • v.24 no.3
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    • pp.209-215
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    • 2003
  • The goal of this study was to investigate the relationship between kinematic and kinetic characteristics of foot joints resisting ground reaction force. Passive elastic joint moment and angular displacement were obtained from the experiment using 3 cameras and force plate. The relationship between joint angle and moment was mathematically modeled by using least square method. The ranges of motion of joints ranged from 5$^{\circ}$ to 7$^{\circ}$ except metatarsophalangeal joint. In the study, we presented simple mathematical models that could relate joint angle and plantar pressure. From this model, we can got the kinematic data of joints which is not available from conventional motion analysis. Furthermore, the model can be used not only for biomechanical model which simulates gait but also for clinical evaluation.

Design of Compliant Hinge Joints inspired by Ligamentous Structure (인대 구조에 기인한 유연 경첩 관절의 설계)

  • Lee, Geon;Yoon, Dukchan;Choi, Youngjin
    • The Journal of Korea Robotics Society
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    • v.14 no.4
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    • pp.237-244
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    • 2019
  • This paper suggests novel types of joint mechanisms composed of elastic strings and rigid bodies. All of the human hinge joints have the articular capsule and a pair of collateral ligaments. These fibrous tissues make the joint compliant and stable. The proposed mechanism closely imitates the human hinge joint structure by using the concept of tensegrity. The resultant mechanism has several characteristics shown commonly from both the tensegrity structure and the human joint such as compliance, stability, lightweight, and non-contact between rigid bodies. In addition, the role and feature of the human hinge joints vary according to the origins of a pair of collateral ligaments. Likewise, the locations of two strings corresponding to a pair of collateral ligaments produce different function and motion of the proposed mechanism. It would be one of the advantages obtained from the proposed mechanism. How to make a joint mechanism with different features is also suggested in this paper.

Investigation of semi-rigid bolted beam connections on prefabricated frame joints

  • Irtem, E.;Turker, K.
    • Structural Engineering and Mechanics
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    • v.12 no.4
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    • pp.397-408
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    • 2001
  • Bolted connections are used commonly in the precast reinforced concrete structures. In such structures, to perform structural analysis, behaviour of connections must be determined. In this study, elastic rotation stiffness of semi-rigid bolted beam connections, applied in industrial precast structures, are determined by finite element methods. The results obtained from numerical solutions are compared with an experimental study carried out for the same connections. Furthermore, stress distributions of the connection zone are determined and a reinforcement scheme is proposed. Thus, a more appropriate reinforcement arrangement for the connection zone is enabled. The connection joint of the prefabricated frame is described as rigid, hinged or elastic, and a static analysis of the frame system is performed for each case. Values of bending moments and displacements obtained from the three solutions are compared and the effects of elastic connection are discussed.

Effect of Ankle Taping Type and Jump Height on Balance during Jump Landing in Chronic Ankle Instability

  • Kim, Mikyoung;Kong, Byungsun;Yoo, Kyungtae
    • Journal of International Academy of Physical Therapy Research
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    • v.11 no.2
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    • pp.2077-2089
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    • 2020
  • Background: Chronic ankle instability is a common injury that decreases balance and negatively affects functional movements, such as jumping and landing. Objectives: To analyze the effect of taping types and jump heights on balance with eyes open and closed during jump landings in chronic ankle instability. Design: Within-subject design. Methods: The study involved 22 patients with chronic ankle instability. They performed both double-leg and single-leg drop jump landings using three conditions (elastic taping, non-elastic taping, and barefoot) on three different jump platforms (30, 38, and 46 cm). Balance was measured using the Romberg's test with eyes open and closed. Results: Interaction effect was not statistically significant. Balance with eyes open and closed was significantly improved in both the elastic taping and non-elastic taping conditions compared to the barefoot condition. There was no significant difference according to the jump height. Conclusion: Individuals with chronic ankle instability demonstrated increased balance ability with eyes open and closed when jump landing. Elastic taping and non-elastic taping on the ankle joint can positively affect balance during landing in individuals with chronic ankle instability.

Characteristics of Strength and Fracture in Strength Mismatched Joint by Dynamic Loading (동적하중 하에서의 강도적 불균질부를 갖는 용접이음재의 강도 및 파괴 특성)

  • ;望月正人;大細充;;豊田政男
    • Journal of Welding and Joining
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    • v.21 no.6
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    • pp.55-63
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    • 2003
  • Welded joint generally has heterogeneity of strength, material, and fracture toughness and it is important to understand the characteristics of material strength and fracture of welded joint considering heterogeneous effect. Characteristics of strength and fracture of an undermatched joint under dynamic loading was studied by round-bar tension tests and thermal elastic-plastic analyses in this paper. The strength and fracture of the undermatched joints should be evaluated based on the effects of the strain rate and the temperature including temperature rise during the dynamic loading. The differences of fracture characteristics like such as ductile-to-brittle transition behavior are well precisely explained from the stress-strain distribution obtained by numerical analysis.

The Effects of Elbow Joint Angle on the Mechanical Properties of the Common Extensor Tendon of the Humeral Epicondyle

  • Han, Jung-Soo
    • Journal of Mechanical Science and Technology
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    • v.18 no.4
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    • pp.582-591
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    • 2004
  • The purpose of this study was to determine the effects of elbow joint angle on mechanical properties, as represented by ultimate load, failure strain and elastic modulus, of bone-tendon specimens of common extensor tendon of the humeral epicondyle. Eight pairs of specimens were equally divided into two groups of 8 each, which selected arbitrarily from left or right side of each pair, positioned at 45$^{\circ}$ and 90$^{\circ}$ of elbow flexion and subjected to tension to failure in the physiological direction of the common extensor tendon. For comparison of the differences in the failure and elastic modulus between tendon and the bone-junction, data for both were evaluated individually. Significant reduction in ultimate load of bone-tendon specimens was shown to occur at 45$^{\circ}$. The values obtained from the bone-tendon junctions with regard to the failure strain were significant higher than those from tendon in both loading directions, but the largest failure strain at the bone-tendon junction was found at 45$^{\circ}$. The elastic modulus was found to decrease significantly at the bone-tendon junction when the loading direction switched from 90$^{\circ}$ to 45$^{\circ}$. Histological observation, after mechanical tensile tests, in both loading directions showed that failure occurred at the interface between tendon and uncalcified fibrocartilage in the thinnest fibrocartilage zone of the bone-tendon junction. We concluded that differences in measured mechanical properties are a consequence of varying the loading direction of the tendon across the bone-tendon specimen.