• 제목/요약/키워드: joint flexibility

검색결과 289건 처리시간 0.028초

Analytical modeling of thin-walled box T-joints

  • Marur, Prabhakar R.
    • Structural Engineering and Mechanics
    • /
    • 제32권3호
    • /
    • pp.447-457
    • /
    • 2009
  • A general analytical method for computing the joint stiffness from the sectional properties of the members that form the joint is derived using Vlasov's thin-walled beam theory. The analytical model of box T-joint under out-of-plane loading is investigated and validated using shell finite element results and experimental data. The analytical model of the T-joint is implemented in a beam finite element model using a revolute joint element. The out-of-plane displacement computed using the beam-joint model is compared with the corresponding shell element model. The results show close correlation between the beam revolute joint model and shell element model.

외발 착지 시 신체적 특성 요인들이 발목 관절 상해에 미치는 영향 (Effects of Physical Characteristics Factors on Ankle Joint Injury during One Leg Drop Landing)

  • 이성열;이효근;권문석
    • 한국응용과학기술학회지
    • /
    • 제37권4호
    • /
    • pp.839-847
    • /
    • 2020
  • 본 연구는 외발 착지 시 신체적 특성 요인들인 발목 유연성, 성별, Q-angle이 발목 관절 상해 요인들에 미치는 영향을 분석하는데 목적이 있었다. 이를 위해 오른발을 주발로 사용하고 체육을 전공하는 20대 남성 16명(나이: 20.19±1.78 years, 체중: 69.54±10.12 kg, 신장: 173.22±4.43 cm), 여성 16명(나이: 21.05±1.53 years, 체중: 61.75±6.97 kg, 신장: 159.34±4.56 cm)을 연구대상자로 선정하였다. 외발 착지 시 신체적 특성 요인들이 발목 관절 상해에 미치는 영향을 확인하기 위하여 첫째, 발목 상해 경험에 따른 하지 관절 움직임과 관절 모멘트의 독립 t-test를 실시하였다(α = .05). 둘째, t-test를 통하여 유의한 차이를 나타낸 변인을 종속변인으로 설정하고 발목 유연성, 성별의 차이, Q-angle을 독립변인으로 지정하여 선형다중회귀분석(Multiple Linear Regression)을 사용하였다(α = .05). 본 연구결과 발목 관절 상해를 경험한 그룹은 상해를 경험하지 않은 그룹과는 다르게 발목 관절의 내전, 무릎 관절의 내측 회전을 통한 착지 전략과 기술을 사용하는 것으로 나타났다. 또한 이러한 움직임은 발목 관절의 신전 모멘트를 증가시키고, 엉덩 관절의 신전 모멘트는 감소시키는 것으로 확인되었다. 특히 발목의 배측굴곡 유연성은 발목과 무릎의 착지전략에 영향을 미치며, 성별의 차이는 발목의 신전 모멘트에 영향을 미치는 것을 알 수 있었다. 따라서 외발 착지 시 신체적 특성 요인들이 발목 관절 상해에 영향을 미치는 요인들임을 확인 할 수 있었다.

The effect of hip joint exercise using an elastic band on dynamic balance, agility and flexibility in healthy subjects: a randomized controlled trial

  • Kang, Dong Hyun;Lee, Woo Hyung;Lim, Song;Kim, Yu Yeong;An, Soung Wook;Kwon, Chang Gyeong;Lee, Gyeong Hee;Choi, Nu Ri;Lee, Na Yeong;Kim, Bo Min;Kim, Jae Hyeon;Chung, Eun Jung
    • Physical Therapy Rehabilitation Science
    • /
    • 제5권4호
    • /
    • pp.198-204
    • /
    • 2016
  • Objective: The purpose of this study was to examine the effects of hip joint exercise using an elastic band on dynamic balance, agility, and flexibility in healthy subjects. Design: Randomized controlled trial. Methods: Thirty-five subjects (between 19 and 23 years) were randomly allocated to two groups: hip flexion exercise (HFE) group (n=17) and the hip abduction exercise (HAE) group (n=18). The HFE group participated in flexion exercise of the hip joint using an elastic band for 50 minutes a day, three days a week for four weeks, while the HAE group participated in abduction exercises of the hip joint using an elastic band for the same period. Dynamic balance was measured using the timed up and go (TUG) test, agility was measured with the standing long jump, and flexibility was measured using the Schober's test (5 cm, 10 cm). Results: The HFE group showed significant differences in the TUG test, standing long jump, and the Schober's test (10 cm) after training (p<0.05). The HAE group showed significant differences in the TUG test, standing long jump and the Schober's test (5 cm, 10 cm) after training (p<0.05). However, there was no significant difference between the HFE group and the HAE group. Conclusions: Flexion and abduction exercises of the hip joint using and elastic band increased dynamic balance, agility, and flexibility in healthy subjects. Additional research on hip joint exercises using an elastic band for improving dynamic balance, agility and flexibility are necessary.

만성관절염 환자의 자가운동에 따른 통증, 피로, 유연성, 건강상태의 비교연구 (A Comparative Study on Pain, Fatigue, Flexibility and Health status between Patients with Self-Exercise and Patient without Self-Exercise)

  • 김선애;김종임
    • 근관절건강학회지
    • /
    • 제9권2호
    • /
    • pp.177-186
    • /
    • 2002
  • The purpose of this study was examine the effect of self-exercise on patients with chronic arthritis. This study was performed from 1999 to 2001 with 107 subjects. Pain, Fatigue, Flexibility and Health status were measured. Data were analysed by SPSSWIN 10. 0 Package program, frequency, independent t-test and One Way ANOVA. The results were as follows : Of the 107 patients who were sutdied, mean age was 62 years and most of common disease were osteoarthritis. 67.4%was doing self-exercise and self-exercise consisted of 17 types of exercise. Fatigue was statistically different by disease type, duration of disease, education respectively. And fatigue, left shoulder flexibility were significantly different by duration of disease. There weren't significant differences between patient with self-exercise and patient without self-exercise on pain fatigue, flexibility and halth status. These findings confirms that self-exercise do not effective in increasing health improvement for the patients with osteoarthritis. From results of this study indicate that patients with arthritis should have taken systematic exercise such as the self-help education program aquatic exercise program for arthritis patient.

  • PDF

Nonlinear analysis of damaged RC beams strengthened with glass fiber reinforced polymer plate under symmetric loads

  • Abderezak, Rabahi;Daouadji, Tahar Hassaine;Rabia, Benferhat;Belkacem, Adim
    • Earthquakes and Structures
    • /
    • 제15권2호
    • /
    • pp.113-122
    • /
    • 2018
  • This study presents a new beam-column model comprising material nonlinearity and joint flexibility to predict the nonlinear response of reinforced concrete structures. The nonlinear behavior of connections has an outstanding role on the nonlinear response of reinforced concrete structures. In presented research, the joint flexibility is considered applying a rotational spring at each end of the member. To derive the moment-rotation behavior of beam-column connections, the relative rotations produced by the relative slip of flexural reinforcement in the joint and the flexural cracking of the beam end are taken into consideration. Furthermore, the considered spread plasticity model, unlike the previous models that have been developed based on the linear moment distribution subjected to lateral loads includes both lateral and gravity load effects, simultaneously. To confirm the accuracy of the proposed methodology, a simply-supported test beam and three reinforced concrete frames are considered. Pushover and nonlinear dynamic analysis of three numerical examples are performed. In these examples the nonlinear behavior of connections and the material nonlinearity using the proposed methodology and also linear flexibility model with different number of elements for each member and fiber based distributed plasticity model with different number of integration points are simulated. Comparing the results of the proposed methodology with those of the aforementioned models describes that suggested model that only uses one element for each member can appropriately estimate the nonlinear behavior of reinforced concrete structures.

지역사회 거주 노인을 위한 스스로 근관절관리 프로그램의 효과 (The Effectiveness of Community-based Muscle and Joint Self Management Program for Older Adults)

  • 송효정;박형근;좌승훈;문수희;김세희;신주연;한지윤;이지은;장미영;현은희
    • Journal of Korean Biological Nursing Science
    • /
    • 제19권3호
    • /
    • pp.191-197
    • /
    • 2017
  • Purpose: The aim of this study was to determine the effectiveness of a community-based muscle and joint self-management program with muscle stretching and muscle strengthening exercises for community-dwelling older adults. Methods: The study was a pre-and-post design in a single group, which examined the effects after the intervention of muscle and joint self-management program for 6 weeks, on the 42 subjects of the elderly who registered in a Community Senior Center in J city. Data analyses were conducted with paired t-test by using a SAS (version 9.2 for Windows) program. Results: The effectiveness of muscle and joint self-management program on shoulder flexibility and right knee extension (flexibility) were significantly improved (t= 2.72, p= .010; t= -2.26, p= .029). Joint symptoms (pain, stiffness), physical functioning, depression, fatigue, and left knee extension were not significantly improved after the muscle and joint self-management program. Conclusion: The results showed the possibility of this 6-week exercise program in improving shoulder and knee flexibility for community-dwelling older adults.

편평족에 대한 관절가동술과 자가신장이 요부의 신장성, 요통과 하지 체중부하 차이에 대한 비교 연구 (The Comparison Study of Ankle Joint Mobilization and Elongation on the Difference of Weight-bearing Load, Low Back Pain and Flexibility in Flat-foots Subjects)

  • 박성두;유달영
    • 대한정형도수물리치료학회지
    • /
    • 제23권2호
    • /
    • pp.9-16
    • /
    • 2017
  • Background: The purpose of this study was to investigate the relationship between the spine and the flat-foot, the stability and the alignment of the posture of the neck to prevent the alignment of the ankle joint operation and the lower back flexibility of the lumbar region according to the type of treatment using active stretching of the triceps, back pain, and to see how they affect weight bearing differences. Methods: The subjects of this study were 24 chronic low back pain patients. They were randomly divided into experimental group and control group. In the experimental group, ankle joint mobilization and active scraping of triceps were performed three times a week for a total of 6 weeks. The control group was performed in the same way without articulation. The range of flexion and extension motion of the lumbar spine and pain degree and difference of weight-bearing were measured before and after the experiment. Results: The model of ankle joint mobilization and calf muscle elongation of flat foot significantly improved the range of flexion and extension motion of the vertebrae (p<.05) and the VAS and distribution of weight-bearing were decreased in both of two groups (p<.05). In other words, the exercise and mobilization help to recover of the balance of the whole musculoskeletal, the vertebrae. Conclusions: The active exercise of the triceps muscle of the lower leg in this study It affects the flexibility of the lumbar spine, the pain and the difference in the weight support of the lower extremities, when we performed ankle joint mobilization for exercise and cramping, pain and the difference in weight support between the two lower limbs.

  • PDF

특이 섭동 이론에 의한 유연성 관절 매니퓰레이터의 적응제어 (Adaptive control of flexible joint manipulators based on the singular perturbation theory)

  • 김응석;양해원
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
    • /
    • pp.7-11
    • /
    • 1991
  • The adaptive control of flexible joint manipulator is the focus of this paper. The full order flexible joint manipulator dynamic system does not allow the determination of a feedback linearization control as for rigid manipulators. This drawback is overcome by a model order reduction based on a singular perturbation strategy. The full order flexible joint manipulator dynamic model is adopted for derivation of the adaptive control law to damp out the elastic oscillations at the joints. It is shown that the joint position error will converge to zero asymptotically and that other signals remain bounded without precise knowledge of parameters of the manipulator and its joint flexibility.

  • PDF

유연도 영향계수법을 이용한 접촉 결합부의 모델링 (Finite Element Modeling of Contact Joints by Flexibility Influence Coefficient)

  • 오제택;조성욱;이규봉
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2003년도 춘계학술대회 논문집
    • /
    • pp.814-819
    • /
    • 2003
  • Machine tool design concepts have evolved towards high efficiency, accurate precision. high structural integrity, and multi-functional systems. Like many other structures, machine tools are also composed of many parts. When these parts are assembled, many kinds of joints are used. In the finite element analysis of these assembled structures, most joints are commonly considered as rigid joints. But, to get the more accurate solution, we need to model these joints in a appropriate manner. In this study, rational dynamic modeling and analysis method for complex structures are studied with special attention to slide way joints. For modeling of slide way joints, a general modeling technique is used by influence coefficients method which is applied to the conversion of detailed finite element model to the equivalent reduced joint model. The theoretical part of this method is illustrated and the method is applied to the structure with slide way joint. In this method. the non-linearity of the contact surfaces is considered within a proper range and the boundary effect of the joint model can be eliminated. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam and slide way joints of the vertical type lathe. The method can also be used to other kinds of joint modeling. The results of these analysis were compared with those of Yoshimura models and rigid joint models. which demonstrated the practical applicability of the proposed method.

  • PDF

유연도 영향계수법을 이용한 접촉결합부가 있는 복합구조물의 동적 해석 (Structural Dynamics Analysis of a Clamp Jointed Complex Ream by Using the Flexibility Influence Coefficient Method)

  • 조재혁;김현욱;최영휴
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1995년도 추계학술대회 논문집
    • /
    • pp.528-533
    • /
    • 1995
  • An analyical method is proposed to construct a clamp jointed structure as an equivalent stiffness matrix element in the finite element modal analysis of a complex beam structure. Static structural analysis was first made for the detail finite element model of the clamp joint. Utilizing the results of this analysis, the equivalent stiffness matrix element was buildup by using the flexibility influence coefficient method and Guyan condensation. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam. And the finite element analysis results were compared to those experimental modal analysis. Comparison shows doog agreement each other Furthermore the effects of normal contact(or clamping) load on the equivalent stiffness matrix was also examined. The equivalent stiffness matrix showed little change in spite of the remakable increase in the contact load on the clamp joint.

  • PDF