• Title/Summary/Keyword: Non-elastic

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The Immediate Effects of Elastic Taping on Center of Pressure and Foot Pressure Distribution

  • Jung-Hee Kim;Jong-Ho Kook;Sang-Mi Lee;Eun-Bin Ko;Song-Yi Han;Yeon-Jeong Kim;Byeong-Jun Min
    • PNF and Movement
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    • v.22 no.1
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    • pp.23-30
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    • 2024
  • Purpose: Ankle instability is a common issue in both daily activities and sports, often leading to recurrent injuries. Elastic taping is a non-pharmacological intervention used to improve ankle stability. This study aimed to investigate the immediate effects of elastic taping on ankle stability, center of pressure (COP) movement, and foot pressure distribution. Methods: A single-group pre-posttest design was employed, with 30 participants included in the study. Plantar pressure and COP parameters were measured before and after the application of elastic taping. Taping was administered in three distinct patterns to enhance ankle stability. Results: Immediate effects of elastic taping were evident in COP parameters. Following taping application, there was a significant decrease in COP total displacement, COP area, and COP velocity. However, no significant changes were observed in plantar pressure parameters. Conclusion: The application of elastic taping in this study demonstrated immediate effects on ankle stability and COP parameters, indicating its potential as a viable intervention for improving balance. Further research with larger sample sizes and long-term follow-up is needed to elucidate the sustained effects of elastic taping on ankle stability.

Thin- Walled Curved Beam Theory Based on Centroid-Shear Center Formulation

  • Kim Nam-Il;Kim Moon-Young
    • Journal of Mechanical Science and Technology
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    • v.19 no.2
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    • pp.589-604
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    • 2005
  • To overcome the drawback of currently available curved beam theories having non-symmetric thin-walled cross sections, a curved beam theory based on centroid-shear center formulation is presented for the spatially coupled free vibration and elastic analysis. For this, the displacement field is expressed by introducing displacement parameters defined at the centroid and shear center axes, respectively. Next the elastic strain and kinetic energies considering the thickness-curvature effect and the rotary inertia of curved beam are rigorously derived by degenerating the energies of the elastic continuum to those of curved beam. And then the equilibrium equations and the boundary conditions are consistently derived for curved beams having non-symmetric thin-walled cross section. It is emphasized that for curved beams with L- or T-shaped sections, this thin-walled curved beam theory can be easily reduced to the solid beam theory by simply putting the sectional properties associated with warping to zero. In order to illustrate the validity and the accuracy of this study, FE solutions using the Hermitian curved beam elements are presented and compared with the results by previous research and ABAQUS's shell elements.

Development of Multi Layered Elastic Pavement Analysis Program Package Considering Temperature Nonlinearty of Asphalt Layer on GUI Environment (아스팔트층 온도 비선형성을 고려한 사용자 편의환경의 다층탄성 프로그램 개발)

  • Choi, Jun-Seong;Seo, Joo-Won;Park, Keun-Bo;Kim, Soo-Il
    • International Journal of Highway Engineering
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    • v.10 no.4
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    • pp.91-101
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    • 2008
  • A multi layered elastic analysis program, IDYSPAP, was developed. The objective of this study was to develop the IDYSPAP program on Graphic User Interface environment for field engineers using Visual Basic, which was considered span of multi-wheels and maximum 4 axles using superposition of linear elastic theorem. It is suggested that this study considers algorithm with dynamic properties of asphalt layer on various temperature and non-linear properties of subbase and subgrade on stress non-linearity for asphalt pavement structure. This Program was modified to divide asphalt layer automatically according to layer division concept. The developed program was verified with initial measuring data in test road sections of KEC (Korea Expressway Co.) using laboratory test results.

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Differential cubature method for vibration analysis of embedded FG-CNT-reinforced piezoelectric cylindrical shells subjected to uniform and non-uniform temperature distributions

  • Madani, Hamid;Hosseini, Hadi;Shokravi, Maryam
    • Steel and Composite Structures
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    • v.22 no.4
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    • pp.889-913
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    • 2016
  • Vibration analysis of embedded functionally graded (FG)-carbon nanotubes (CNT)-reinforced piezoelectric cylindrical shell subjected to uniform and non-uniform temperature distributions are presented. The structure is subjected to an applied voltage in thickness direction which operates in control of vibration behavior of system. The CNT reinforcement is either uniformly distributed or functionally graded (FG) along the thickness direction indicated with FGV, FGO and FGX. Effective properties of nano-composite structure are estimated through Mixture low. The surrounding elastic foundation is simulated with spring and shear constants. The material properties of shell and elastic medium constants are assumed temperature-dependent. The motion equations are derived using Hamilton's principle applying first order shear deformation theory (FSDT). Based on differential cubature (DC) method, the frequency of nano-composite structure is obtained for different boundary conditions. A detailed parametric study is conducted to elucidate the influences of external applied voltage, elastic medium type, temperature distribution type, boundary conditions, volume percent and distribution type of CNT are shown on the frequency of system. In addition, the mode shapes of shell for the first and second modes are presented for different boundary conditions. Numerical results indicate that applying negative voltage yields to higher frequency. In addition, FGX distribution of CNT is better than other considered cases.

The Effect of Vastus Lateralis Inhibition Taping Using Non-elastic Tape on the Electromyographic Activity of the Vastus Medialis Oblique and Vastus Lateralis During Isometric Knee Extension (비탄력테이프를 이용한 외측광근 억제가 슬관절 등척성 신전 시 외측광근과 내측광근의 근활성도에 미치는 영향)

  • Lee, Da-Bee;Kim, Suhn-Yeop
    • Journal of Korean Physical Therapy Science
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    • v.23 no.1
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    • pp.24-32
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    • 2016
  • Purpose: Muscle imbalance around the knee region, especially quadriceps imbalance, is considered one of the main contributing factors to the development and progression of knee dysfunction based on the changes observed via electromyography (EMG). This study aimed to investigate the effect of vastus lateralis (VL) inhibition taping using non-elastic tape on the EMG activity of the vastus medialis oblique (VMO) and VL during isometric knee extension. Method: Thirty-three healthy young adults (11 males and 22 females) were recruited. With and without VL inhibition taping, the participants performed isometric knee extension in the sitting position for a total of 7 seconds. Result: VMO/VL EMG ratio significantly increased after VL inhibition taping (p<.05). Conclusion: These findings suggest that VL inhibition taping may contribute to VL inhibition and may help improve VMO/VL ratio in young adults. We expect VL inhibition taping to be useful in individuals with greater VL than VMO activity

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Static Non-linear Finite Element Analysis of Spatial Cable Networks (3차원 케이블망의 초기평형상태 결정 및 정적 비선형 유한요소해석)

  • 김문영;김남일;안상섭
    • Computational Structural Engineering
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    • v.11 no.1
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    • pp.179-190
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    • 1998
  • A geometrically nonlinear finite element formulation of spatial cable networks is presented using two cable elements. Firstly, derivation procedures of tangent stiffness and mass matrices for the space truss element and the elastic catenary cable element are summarized. The load incremental method based on Newton-Raphson iteration method and the dynamic relaxation method are presented in order to determine the initial static state of cable nets subjected to self-weights and support motions. Furthermore, static non-linear analysis of cable structures under additional live loads are performed based on the initial configuration. Challenging example problems are presented and discussed in order to demonstrate the feasibility of the present finite element method and investigate static nonlinear behaviors of cable nets.

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Estimating floor spectra in multiple degree of freedom systems

  • Calvi, Paolo M.;Sullivan, Timothy J.
    • Earthquakes and Structures
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    • v.7 no.1
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    • pp.17-38
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    • 2014
  • As the desire for high performance buildings increases, it is increasingly evident that engineers require reliable methods for the estimation of seismic demands on both structural and non-structural components. To this extent, improved tools for the prediction of floor spectra would assist in the assessment of acceleration sensitive non-structural and secondary components. Recently, a new procedure was successfully developed and tested for the simplified construction of floor spectra, at various levels of elastic damping, atop single-degree-of-freedom structures. This paper extends the methodology to multi-degree-of-freedom (MDOF) supporting systems responding in the elastic range, proposing a simplified modal combination approach for floor spectra over upper storeys and accounting for the limited filtering of the ground motion input that occurs over lower storeys. The procedure is tested numerically by comparing predictions with floor spectra obtained from time-history analyses of RC wall structures of 2- to 20-storeys in height. Results demonstrate that the method performs well for MDOF systems responding in the elastic range. Future research should further develop the approach to permit the prediction of floor spectra in MDOF systems that respond in the inelastic range.

Mechanical analysis of functionally graded spherical panel resting on elastic foundation under external pressure

  • Cao, Yan;Qian, Xueming;Fan, Qingming;Ebrahimi, Farbod
    • Structural Engineering and Mechanics
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    • v.74 no.2
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    • pp.297-311
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    • 2020
  • The main purpose of this study is to analyze the effects of external pressure on the vibration and buckling of functionally graded (FG) spherical panels resting of elastic medium. The material characteristics of the FG sphere continuously vary through the thickness direction based on the power-law rule. In accordance with first-order shear deformation shell theory and by the use of Ritz formulation the governing equations are presented. In this regard, the beam functions are applied in two-dimensions for different sets of boundary supports. The Winkler and Pasternak models of elastic foundations are also taken into account. In order to show the validity and applicability of the presented formulation, various comparison studies are given. Furthermore, a diverse range of numerical results is reported to check the impacts of geometrical and material parameters along with external pressure on the vibration and buckling analysis of FG spherical panels.

Non-equibiaxial residual stress evaluation methodology using simulated indentation behavior and machine learning

  • Seongin Moon;Minjae Choi;Seokmin Hong;Sung-Woo Kim;Minho Yoon
    • Nuclear Engineering and Technology
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    • v.56 no.4
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    • pp.1347-1356
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    • 2024
  • Measuring the residual stress in the components in nuclear power plants is crucial to their safety evaluation. The instrumented indentation technique is a minimally invasive approach that can be conveniently used to determine the residual stress in structural materials in service. Because the indentation behavior of a structure with residual stresses is closely related to the elastic-plastic behavior of the indented material, an accurate understanding of the elastic-plastic behavior of the material is essential for evaluation of the residual stresses in the structures. However, due to the analytical problems associated with solving the elastic-plastic behavior, empirical equations with limited applicability have been used. In the present study, the impact of the non-equibiaxial residual stress state on indentation behavior was investigated using finite element analysis. In addition, a new nonequibiaxial residual-stress prediction methodology is proposed using a convolutional neural network, and the performance was validated. A more accurate residual-stress measurement will be possible by applying the proposed residual-stress prediction methodology in the future.

Comparison of Tension According to the Type of Sling Cord during the Bridging Exercise with Sling in Stroke Patients (뇌졸중 환자의 교각 운동 시 슬링 줄의 종류에 따른 장력 비교)

  • Jang, Gwonuk;Chang, Jongsung
    • Journal of Korean Medicine Rehabilitation
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    • v.29 no.2
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    • pp.189-194
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    • 2019
  • Objectives The purpose of this study was to examine comparison of tension according to the type of sling cord during the bridging exercise with sling in stroke patients. Methods Twenty six stroke patients were recruited for this study. Subjects were randomly performed sling bridging exercise with three types of sling cords such as nonelastic cord with affected side-nonelastic cord with non affected side (NC-NC), nonelastic cord with affected side-elastic cord with non affected side (NC-EC), and elastic cord with affected side-nonelastic cord with non affected side (EC-NC). They were measured tension with a tensiometer of sling cord during the bridging exercise with sling. Results The tension of sling cord was significantly different in affected side, non affected side, and tension ratio of affected side/non affected side. There were significant differences tension in NC-EC from NC-NC and EC-NC and the NC-EC method was increased tension of affected side and decreased tension of non affected side. Conclusions These results showed that the NC-EC method was improved the symmetry of affected side and non affected side. Sling exercise with appropriate type of sling cord should be increased activities of affected side and improved recovery in stroke patients.