• Title/Summary/Keyword: Transverse Effect

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Bucking Load Analysis of Spot-Welded Structures (점용접된 구조물의 좌굴하중해석)

  • 이현철;심재준;안성찬;한근조
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1999.10a
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    • pp.265-272
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    • 1999
  • This stability of a plate structure is very crucial problem which results in wrinkle and bucking. In this study, the effect of the pattern of spot-welding points of the two rectangular plates on the compressive and shear bucking load is studied with respect to the thickness, aspect ratio of plates and number of welding spots. Buckling coefficient of the plate not welded was compared with that of two plates with various thickness to extract the effect of thickness. The effect of number of welding spots are studied in two directions, longitudinal and transverse directions. The conclusions obtained were that the reinforcement effect was maximized when the aspect ratio was close to 1.75 at compressive load condition and that the effect of number of welding spots in transverse direction was larger than that in longitudinal direction at shearing load condition.

A theoretical calculation of coupled free, transverse vibration of the multi-supported shaft system by the finite element method (유한요소법에 의한 다점지지축계의 연성자유횡진동 계산에 관한 연구)

  • 유광택;전효중
    • Journal of Advanced Marine Engineering and Technology
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    • v.10 no.4
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    • pp.41-49
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    • 1986
  • With the trend towards high propulsive level, increasing ship's dimensions and heavier shaft systems supported by the hull structure of relatively stiffness in modern ships, transverse vibrations of propulsion shaft system have become one of the problems that should be predicted in the early design stage. Regarding transverse vibrations, coupling terms such as oilfilm, gyroscope and hydrodynamic effect of the propeller exist between the vertical and horizontal vibration, furthermore for the shaft system with strut and bossing its physical properties incorporated with hull structure must be considered. In order to predict the transverse vibratory condition of the propulsion shaft and take some appropriate countermeasures, it is necessary to make a fairly strict estimation of the vibratory behaviours of it. In this paper, theoretical approach using the finite element method is investigated to calculate natural frequencies and vibration modes for coupled free transverse vibrations of shaft system in two planes. Based on the method investigated a digital computer program is developed and is applied to calculate the above-mentioned vibrations of an experimental model shaft system. The results of the calculation are compared with those of the experimental measurements and they show an acceptable agreement.

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A Study on the Dynamic Characteristics of a Composite Beam with a Transverse Open Crack (크랙이 존재하는 복합재료 보의 동적 특성 연구)

  • 하태완;송오섭
    • Journal of KSNVE
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    • v.9 no.5
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    • pp.1019-1028
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    • 1999
  • Free vibration characteristics of cantilevered laminated composite beams with a transverse non0propagating open carck are investigated. In the present analysis a special ply-angle distribution referred to as asymmetric stiffness configuration inducing the elastic coupling between chord-wise bending and extension is considered. The open crack is modelled as an equivalent rotational spring whose spring constant is calculated on the basis of fracture mechanics of composite material structures. Governing equations of a composite beam with a open crack are derived via Hamilton's Principle and Timoshenko beam theory encompassing transverse shear and rotary inertia effect. the effects of various parameters such as the ply angle, fiber volume fraction, crack depth, crack position and transverse shear on the free vibration characteristics of the beam with a crack is highlighted. The numerical results show that the natural frequencies obtained from Timoshenko beam theory are always lower than those from Euler beam theory. The presence of intrinsic cracks in anisotropic composite beams modifies the flexibility and in turn free vibration characteristics of the structures. It is revealed that non-destructive crack detection is possible by analyzing the free vibration responses of a cracked beam.

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Bending analysis of exponentially varied FG plates using trigonometric shear and normal deformation theory

  • Sunil S. Yadav;Keshav K. Sangle;Mandar U. Kokane;Sandeep S. Pendhari;Yuwaraj M. Ghugal
    • Advances in aircraft and spacecraft science
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    • v.10 no.3
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    • pp.281-302
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    • 2023
  • In this paper, bending analysis of exponentially varying functionally graded (FG) plate is presented using trigonometric shear deformation theory (TSDT) considering both transverse shear and normal deformation effects. The in-plane displacement field consists of sinusoidal functions in thickness direction to include transverse shear strains and transverse displacement include the effect of transverse normal strain using the cosine function in thickness coordinate. The governing equations and boundary conditions of the theory are derived using the virtual work principle. System of governing equations, for simply supported conditions, Navier's solution technique is used to obtain results. Plate material properties vary across thickness direction according to exponential distribution law. In the current theory, transverse shear stresses are distributed accurately through the plate thickness, hence obviates the need for a shear correction factor. TSDT results are compared with those from other theories to ensure the accuracy and effectiveness of the present theory. The current theory is in excellent agreement with the semi-analytical theory.

Effect of Virtual Reality Based Ring Fit Adventure Core Exercise on the Thickness of the Transverse Abdominis, Internal Oblique and External Oblique Muscle (가상현실 기반의 링 피트 어드벤처 코어 운동이 배가로근, 배속빗근, 배바깥빗근의 두께에 미치는 영향)

  • Yoon, Sam-Won;Yoon, Sung-Young;Park, Han-Kyu
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.4
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    • pp.93-102
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    • 2022
  • Purpose : The purpose of this study was to analyze the change in thickness of transvers abdominis, internal oblique, and external oblique when virtual reality based ring fit adventure is applied to young adults in order to investigate the effect of ring fit adventure on core stabilization. Methods : 30 subjects participated in the experiment. Subjects were randomly assigned to two groups. 15 subjects performed ring fit adventure core exercise (experimental group) and 15 subjects bridge and dead bug exercise (control group). The ring fit adventure core exercise program consists of 6 types, 1) bow pull, 2) overhead lunge twist, 3) pendulum bend, 4) seated ring raise, 5) plank, 6) warrior III pose. Each exercise was performed for 5 minutes, for a total of 30 minutes. The bridege and dead bug exercise were performed for 15 minutes each for a total of 30 minutes. All interventions were performed 3 times a week for 4 weeks. Thickness of the abdominal muscles was measured with a ultrasound. The paired t-test was used to compare the thickness of the transverse abdominis, internal oblique, and external oblique before and after intervention, and the comparison between groups was analyzed using the independent t-test. Results : As a result, in the experimental group, thickness of transverse abdominis and internal oblique increased significantly (p<.05), but external oblique decreased significantly (p<.05), and in the control group, thickness of transverse abdominis, internal oblique, and external oblique increased significantly (p<.05). There was a significant difference in external oblique in the difference between groups (p<.05). Conclusion : These study results showed that core exercise using ring fit adventure can reduce external oblique and increased selective muscle activity of transverse abdominis and internal oblique of the deep abdominal muscles, so it is meaningful as an effective intervention for core stabilization.

The Effects of Transverse Abdominis Ratio and Balance Ability during Bridge Exercises on Different Support Surface (지지면 변화에 따른 교각운동이 복횡근 두께와 균형능력에 미치는 영향에 관한 연구)

  • Ann, Jun-il;Kim, Yoon-hwan;Park, Jong-hang;Ann, Mi-rae;Jung, Yeon-woo;Kim, Tae-won
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.23 no.1
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    • pp.23-30
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    • 2017
  • Purpose: The purpose of this study was to investigate the effect of transverse abdominis ratio and balance ability during bridge exercises on different support surface. Methods: The subjects were 20 students at G University. Ultrasound equipment was used to measure the transverse abdominisratio and the computerized balance measurement equipment was used to measure the balance ability before and after bridge exercises on different support surface. Results: Transverse abdominis ratio change between the groups was a significant difference only in the unstable support surface training group (p<.05). Normal standing eye close balance ability change between the groups was significantly different only in the unstable support surface training group (p<.05). The changes in the transverse abdominis ratio after 7 days of exercise and 14 days after exercise were significantly different between the groups (p<.05). Normal standing eye close balance ability showed a significant difference at 7 days after exercise and 14 days after exercise (p<.05). Conclusions: It is more effective to balance ability and ratio of the transverse abdominis when bridge exercises on an unstable support surface than to perform bridge exercises on a stable support surface. Therefore, we propose an effective program for patients with instability of the lumbar in clinical practice. bridge exercises on different support surface.

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Reduction of Susceptibility Effect Using Frequency Modulation DANTE (주파수 변조 DANTE를 이용한 자화율 효과의 감소)

  • Chung, S.T.;Hong, I.K.;Kim, J.H.;Ro, Y.M.;Cho, Z.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.11
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    • pp.167-170
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    • 1995
  • An frequency modulated (FM) DANTE pulse sequence generates a quadratic phase toward the transverse of image by an FM RF pulse. In the image of a serious susceptibility effect, the phase due to the difference of the susceptibility in the pixel occurs susceptibility error which arise signal loss. But the signal loss due to the susceptibility effect in the pixel is reduced when the quadratic phase adds in the pixel. In this paper, we have generated a quadratic function toward the transverse (X-Y) using FM DANTE sequence and the susceptibility effect is reduced in the gradient echo (GE) imaging. Computer simulation and experimental results is obtained by using a whole-body KAIS 2.0T NMR system.

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Effective Channel Mobility of AlGaN/GaN-on-Si Recessed-MOS-HFETs

  • Kim, Hyun-Seop;Heo, Seoweon;Cha, Ho-Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.6
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    • pp.867-872
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    • 2016
  • We have investigated the channel mobility of AlGaN/GaN-on-Si recessed-metal-oxide-semiconductor-heterojunction field-effect transistors (recessed-MOS-HFET) with $SiO_2$ gate oxide. Both field-effect mobility and effective mobility for the recessed-MOS channel region were extracted as a function of the effective transverse electric field. The maximum field effect mobility was $380cm^2/V{\cdot}s$ near the threshold voltage. The effective channel mobility at the on-state bias condition was $115cm^2/V{\cdot}s$ at which the effective transverse electric field was 340 kV/cm. The influence of the recessed-MOS region on the overall channel mobility of AlGaN/GaN recessed-MOS-HFETs was also investigated.

The Poisson effect on the curved beam analysis

  • Chiang, Yih-Cherng
    • Structural Engineering and Mechanics
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    • v.19 no.6
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    • pp.707-720
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    • 2005
  • The bending stress formula that taking into account the transverse deformation is developed for plane-curved, untwisted isotropic beams subjected to loadings that result in deformations in the plane of curvature. In order to account the transverse Poisson contraction effect, a new constitutive relation between force resultants, moment resultants, mid-plane strains and deformed curvatures for a curved plate is derived in a $6{\times}6$ matrix form. This constitutive relation will provide the fundamental basis to the analyses of curved structures composing of isotropic or anisotropic materials. Then, the bending stress formula of a curved isotropic beam can be deduced from this newly developed curved plate theory. The stress predictions by the present analysis are compared to those by the analysis that neglected the Poisson contraction effect. The results show that the Poisson effect becomes more significant as the Poisson ratio and the curvature are getting larger.

A Study on the 2-Dimensional Flux Distribution Analysis of a Double Sided Linear Induction Motor (양축식 선형유도 전동기의 2차원 자속분포 해석에 관한 연구)

  • 임달호;김학린;조윤현
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.1
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    • pp.29-35
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    • 1990
  • This paper proposes a tow-dimensional magnetic flux distribution analysis of the double-sided linear induction motor(DLIM). Both the longitudinal end-effect and the transverse edge-effect, which are due to the finite length and width of the primary stator, are considered. Also each force which is due to the variation of slip frequency was computed to show the fact that the thrust force of DLIM is dependent on both the longitudinal end-effect and the transverse edge-effect. To ascertain the propriety of this analysis, the simulated results of the magnetic flux density distribution in the airgap are compared to the experimental data.

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