• Title/Summary/Keyword: dynamic/static

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A Comparative Study on Bearing Capacity of Single Pile Based on Calculation Method (산정방법에 따른 단말뚝의 지지력 비교연구)

  • 이영대;심재현
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.39 no.2
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    • pp.124-133
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    • 1997
  • Pile load test is good for estimating pile bearing capacity, but using this method is limited by time and cost required. Dynamic and static method is more convenient and economical, but confidence of estimated value by dynamic and static method are lower than that of pile load test. After being compared pile bearing capacity data obtained from pile load test with those of other two methods, the results from this study were summarised as follows. For allowable bearing capacity values greater than 175t per pile, bearing capacity acquired from static method was higher than that acquired from pile load test, whereas bearing capacity acquired from pile load test was higher than that acquired from static method for values under 175 per pile. It was that variance of bearing capacity was large when bearing capacity obtained by dynamic method was higher than 250t. Also bearing capacity based on dynamic method was higher than that based on pile load test. Allowable bearing capacity get from dynamic method suggested that carefull precautions are necessary in application for allowable bearing capacity values higher than 2S0ton per pile.

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Study on the Static and Dynamic Structural Analysis Procedure of Excavators (굴삭기의 정적/동적 강도 해석법에 대한 연구)

  • Choung, Joon-Mo;Kim, Gyu-Sung;Jang, Young-Sik;Choe, Ick-Hung;Heo, Min-Soo
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.537-543
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    • 2003
  • This paper presents the improved procedure to assess static and dynamic strength of crawler type excavators. A fully integrated model including front attachment and chassis was prepared for structural analysis. In this paper, two types of loading input methods were investigated and the method imposing digging force directly on bucket tooth was more convenient than imposing cylinder reaction force on cylinder pin even if the two methods showed no discrepancy in analysis results. Static strength analysis was carried out for eight analysis scenarios based on two extreme digging positions, maximum digging reach position and maximum digging force positions. The results from static strength analysis were compared with measured stresses, cylinder pressures and digging forces and showed a good quantitative agreement with measured data. Dynamic strength analysis was carried out for simple reciprocation of boom cylinders. It was recognized that the effect of compressive stiffness of hydraulic oil was very important for dynamic structural behavior. The results from dynamic strength analysis including hydraulic oil stiffness were also compared with measured acceleration data and showed a qualitative agreement with measured data.

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Testing for Identification of Dynamic Properties of Viscoelastic Material Subject to Large Static Deformation (정적 대변형을 받고 있는 점탄성 재료의 동적 물성치 규명 시험)

  • 이완술;이호정;조지현;김진성;윤성기;김광준
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.2
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    • pp.132-143
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    • 2003
  • Viscoelastic components for vibration isolation or shock absorption in automobiles, machines and buildings are often subject to a high level of static deformation. From the dynamic design point of view, it is requisite to predict dynamic complex stiffness of viscoelastic components accurately and efficiently. To this end, a systematic procedure for complex modulus measurement of the viscoelastic material under large static deformation is often required in the industrial fields. In this paper, dynamic test conditions and procedures for the viscoelastic material under small oscillatory load superimposed on large static deformation are discussed. Various standard test methods are investigated in order to select an adequate test methodology. The influence of fixed boundary condition in the compression tests upon complex stiffness are investigated and an effective correction technique is proposed. Then the uniaxial tension and compression tests are performed and its results are compared with analysis results from conventional constitutive models.

Effects of Static, Dynamic, PNF Stretching on the Isokinetic Peak Torque

  • Lim, Chang-Hun
    • The Journal of Korean Physical Therapy
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    • v.23 no.6
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    • pp.37-42
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    • 2011
  • Purpose: The aim of this study is to suggest the basic materials for proposing effective and efficient methods when stretching by measuring isokinetic muscular strength according to static, dynamic and PNF stretching. Methods: This study was conducted on 45 healthy persons (male and female) in their twenties who are attending universities. The subjects are randomly divided into three (3) groups, and static stretching is applied in group 1, dynamic stretching is applied in group 2 and PNF stretching is applied in group 3. After carrying out static, dynamic and PNF stretching, peak torque was measured using isokinetic muscular strength measurement. Results: According to the results, at $60^{\circ}$/sec and $180^{\circ}$/sec isokinetic peak torque of the knee joint according to types of stretching, the largest changes were shown in Group 2 extension and flexion, and the least changes were shown in Group 1. There were significant differences among the three groups (p<0.05), and the result of after-analysis by LSD showed that there were significant differences between Groups 1 and 2, and Groups 1 and 3 (p<0.05). Conclusion: The intention of this study was to determine the peak torque using Cybex after applying three stretching methods to hamstring muscles, and the case of dynamic and PNF stretching was found to be more significant in both the $60^{\circ}$/sec and $180^{\circ}$/sec angular speeds than that of static stretching. Using the results of such studies, if dynamic and PNF stretching are applied together with warming-up before performing sports, the risk of suffering wounds would reduce and the exactness of sports would increase.

Dynamic to static eccentricity ratio for site-specific earthquakes

  • Kamatchi, P.;Ramana, G.V.;Nagpal, A.K.;Iyer, Nagesh R.;Bhat, J.A.
    • Earthquakes and Structures
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    • v.9 no.2
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    • pp.391-413
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    • 2015
  • Damage of torsionally coupled buildings situated on soil sites has been reported in literature, however no site-specific studies are available for torsionally coupled buildings having site characteristics as a parameter. Effect of torsion is being accounted in seismic codes by the provision of design eccentricity where the dynamic to static eccentricity ratio is a parameter. In this paper, a methodology to determine dynamic to static eccentricity ratio of torsionally coupled buildings has been demonstrated for Delhi region for two torsionally coupled buildings on three soil sites. The variations of average and standard deviations of frame shears for stiff and flexible edges are studied for four eccentricity ratios for the two buildings for the three sites. From the limited studies made, it is observed that the dynamic to static eccentricity ratios observed for site-specific earthquakes are different from Indian seismic code specified value, hence a proposal is made to include a comment in Indian seismic code. Methodology proposed in this paper can be adopted for any region, for the estimation of dynamic to static eccentricity ratio for site specific earthquake.

Importance of Dynamic Cue in Silhouette-Based Gait Recognition (실루엣 기반 걸음걸이 인식 방법에서 동적 단서의 중요성)

  • Park Hanhoon;Park Jong-Il
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.3 s.303
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    • pp.23-30
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    • 2005
  • As a human identification technique, gait recognition has recently gained significant attention. Silhouette-based gait recognition is one of the most popular methods. This paper aims to investigate features that determine the style of walking in silhouette-based gait recognition. Gait can be represented using two cues: static(shape) cue and dynamic(motion) cue. Most recently, research results have been reported in the literature that the characteristics of gait are mainly determined by static cue but not affected by dynamic cue. Unlike this, experimental results in this paper verifies that dynamic cue is as important as and in many cases more important than static cue. For experiments, we use two well-blown gait databases: UBC DB and Southampton Small DB. The images of UBC DB correspond to the 'ordinary' style of walking. The images of Southampton Small DB correspond to the 'disguised' (not ordinary by wearing special clothes or bags) style of walking. As results of experiments, the recognition rate was 100% by static cue and $95.2\%$ by dynamic cue for the images of UBC DB. For the images of Southampton Small DB, the recognition rate was $50.0\%$ by static cue and $55.8\%$ by dynamic cue. The risk against correct recognition was 0.91 by static cue and 0.97 by dynamic cue for the images of UBC DB. For the images of Southampton Small DB, the risk was 0.98 by static cue and 0.98 by dynamic cue. Consequently, the characteristics of ordinary gait are mainly determined by static cue but that of disguised gait by dynamic cue.

The effect of trunk stabilization exercise according to face-to-face, non-face-to-face, and self-exercise on balance ability (대면, 비대면, 자가운동에 따른 체간안정화 운동이 균형능력에 미치는 영향)

  • Kyung-eun Lee;So-eun Kim;Hyun-jeong Kim;Jeongwoo Jeon;Jiheon Hong;Jaeho Yu;Jinseop Kim;Seong-Gil Kim;Yeongyo Nam;Dongyeop Lee
    • Journal of Advanced Technology Convergence
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    • v.3 no.1
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    • pp.65-72
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    • 2024
  • Study of the effect of interbody stabilization exercises on the static and dynamic balance of face-to-face, non-face-to-face, and self-group. We recruited healthy young adults The subjects were randomly divided into three groups to perform inter-body stabilization exercises, and static and dynamic balance were measured, respectively, before and after intervention. In the Face to Face Group, dynamic balance significantly increased in the anterior and posteriomedial directions before and after intervention. There was also a significant increase in static balance. In the Non face to face Group, there was a significant increase in the three directions of dynamic and static balance. The self-exercise group significantly increased in three directions of dynamic balance, but there was no significant difference in static balance. No significant differences between groups were found in any variables. The results of this study showed that interbody stabilization exercises are effective in improving static and dynamic balance. In the face-to-face group, the inter-body stabilization exercise was effective in improving dynamic balance and static balance, and in the non-face-to-face group, the inter-body stabilization exercise was effective in improving dynamic balance and static balance. In the self-contained group, it was effective in improving dynamic balance.

Compromise Optimal Design using Control-based Analysis of Hypersonic Vehicles

  • Liu, Yanbin;bing, Hua
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.2
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    • pp.137-147
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    • 2015
  • Hypersonic vehicles exhibit distinct dynamic and static characteristics, such as unstable dynamics, strict altitude angle limitation, large control bandwidth, and unconventional system sensitivity. In this study, compromise relations between the dynamic features and static performances for hypersonic vehicles are investigated. A compromise optimal design for hypersonic vehicles is discussed. A parametric model for analyzing the dynamic and static characteristics is established, and then the optimal performance indices are provided according to the different design goals. A compromise optimization method to balance the dynamic and static characteristics is also discussed. The feasibility of this method for hypersonic vehicles is demonstrated.

The Effect of Microstructure on the Static and Dynamic Deformation Behavior of Ti-6Al-4V Alloy (Ti-6Al-4V 합금의 미세조직에 따른 정적 및 동적 변형에 관한 연구)

  • Lee D. G.;Lee Y. H.;Lee S. H.;Hur S. M.;Lee C. S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.10a
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    • pp.277-280
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    • 2001
  • The effects of a -phase morphology on the static and dynamic deformation behavior of a Ti-6Al-4V alloy was investigated in this study. Static tension test, static and dynamic tension test and hot compression test were conducted on three microstructures of Ti-6Al-4V alloy, i.e., equiaxed, widmanstatten and bimodal microstructures. Fracture surfaces of all three microstructures represented ductile fracture appearance, though the formation of adiabatic shear bands was noticed at dynamic torsion test. The susceptibility of forming adiabatic shear bands was greatest in the equiaxed microsoucture and lowest in the bimodal microstructure, which was evidenced by hot compression test.

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Failure analysis of composite plates under static and dynamic loading

  • Ray, Chaitali;Majumder, Somnath
    • Structural Engineering and Mechanics
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    • v.52 no.1
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    • pp.137-147
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    • 2014
  • The present paper deals with the first ply failure analysis of the laminated composite plates under various static and dynamic loading conditions. Static analysis has been carried out under patch load and triangular load. The dynamic failure analysis has been carried out under triangular pulse load. The formulation has been carried out using the finite element method and a computer code has been developed. The first order shear deformation theory has been applied in the present formulation. The displacement time history analysis of laminated composite plate has been carried out and the results are compared with those published in literature to validate the formulation. The first ply failure load for laminated composite plates with various lamination schemes under static and dynamic loading conditions has been calculated using various failure criteria. The failure index-time history analysis has also been carried out and presented in this paper.