• Title/Summary/Keyword: rigidity

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Arch-to-beam rigidity analysis for V-shaped rigid frame composite arch bridges

  • Gou, Hongye;Pu, Qianhui;Zhou, Yang;Hong, Yu
    • Steel and Composite Structures
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    • v.19 no.2
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    • pp.405-416
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    • 2015
  • We proposed the concept of nominal rigidity of a long-span V-shaped rigid frame composite arch bridge, analyzed the effects of structural parameters on nominal rigidity, and derived a theoretical nominal rigidity equation. In addition, we discussed the selection of the arch-to-beam rigidity ratio and its effect on the distribution of internal forces, and analyzed the influence of the ratio on the internal forces. We determined the delimitation value between rigid arch-flexible beam and flexible arch-rigid beam. We summarized the nominal rigidity and arch to beam rigidity ratios of existing bridges. The results show that (1) rigid arch-flexible beam and flexible arch-rigid beam can be defined by the arch-to-beam rigidity ratio; (2) nominal rigidities have no obvious differences among the continuous rigid frame composite arch bridge, V-shaped rigid frame bridge, and arch bridge, which shows that nominal rigidity can reflect the global stiffness of a structure.

Clinical study on Soyang-Kyong negative acupuncture effect of spasticity or rigidity (강직(强直) 및 경직(硬直)의 소양경(少陽經) 사침치료(瀉針治療)에 대한 임상적(臨床的) 고찰(考察))

  • Park, Jin-Yong;Kim, Jin-Gyu;Kim, Soo-Jung;Lee, Woon-Suk;Kim, Yong-Chan;Jung, Myong-Gul
    • The Journal of Internal Korean Medicine
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    • v.21 no.5
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    • pp.845-850
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    • 2000
  • Objective : This study was to investigate Soyang-Kyong negative acupuncture treatment of spasticity or rigidity in 41 patients. Methods : Let Sadok, Yangnungch' on, Kuho in side of spasticity or rigidity have negative acupuncture in the skin. Result and Conclusion : 1. Spasticity or rigidity was improved 33 case of 41 case by Soyang-Kyung negative acupuncture. 2. The spasticity was improved more than the rigidity. 3. Spasticity or rigidity of Basal Ganglia, Periventricular Whete Matter, Thalamrs is improved more than Spasticity or rigidity of M.C.A territory, Pons. 4. Spasticity or rigidity of Cb-mfaction is improved more than Spasticity or rigidity of Cb-hemorrloge.

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Analysis on Exact Rigidity and Free Vibration of Trapezoidal Corrugated Plates (사다리꼴형 주름판의 엄밀강성 및 자유진동 해석)

  • Kim, Young-Wann;Jung, Kang
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.7
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    • pp.787-794
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    • 2016
  • In this study, the exact rigidity and the free vibration of trapezoidal corrugated plate are analyzed by being based on the Kirchhoff's plate theory and the Ritz method. The previous rigidity of corrugated plate analyzed by considering just a geometric characteristic, a basic assumption and an equivalent idea can cause large errors in practical behaviors. Accordingly, the exact rigidity supplemented by correction factors of the theoretical rigidity is needed. Therefore an analysis on the exact rigidity and the free vibration using the rigidity for the plate is performed in this paper.

Buckling Analysis of Rectangular Lattice Dome According to Rise-Ratio -Evaluate Rigidity of Roof Material By Effective Width of Frame (라이즈비에 따른 사각형 격자 돔의 좌굴해석 -지붕재의 강성을 프레임의 유효폭으로 평가)

  • Park, Sang-Hoon;Suk, Chang-Mok;Jung, Hwan-Mok;Kwon, Young-Hwan
    • Journal of Korean Association for Spatial Structures
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    • v.3 no.2
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    • pp.69-75
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    • 2003
  • In case of rectangular lattice dome which shearing rigidity is very small, it has a concern to drop Buckling strength considerably by external force. So, by means of system to increase buckling-strength, there is a method of construction that lattice of dome is one with roof material. In a case like this, shearing rigidity of roof material increases buckling-strength of the whole of structure and can be designed economically from the viewpoint of practice. In case of analysis is achieved considering roof material that adheres to lattice of dame, there is method that considers the rigidity that use effective width frame as method to evaluate rigidity of roof material. therefore, this study is aimed at deciding effective width of roof material united with rectangular lattice dome to evaluate rigidity of roof material by effective width of frame and investigating how much does rigidity of roof material united with lattice of dome increase buckling-strength of the whole of structure according to rise-ratio. Conditions of loading are vertical-type-uniform loading. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems.

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Modeling and Structural Analysis on the Bending Rigidity of Nonwoven Fabrics (부직포의 굽힘강성에 대한 모델링과 구조해석에 관한 연구)

  • ;Tushar K. Ghosh
    • Textile Science and Engineering
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    • v.36 no.6
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    • pp.455-462
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    • 1999
  • A theoretical prediction of bending rigidity of nonwoven fabrics with different bonding characteristics is presented. To study the bending behavior of nonwoven fabrics, we have modified Freeston & Platt's model assuming both no freedom and complete freedom behavior. By reconfiguring the fiber number in a unit cell ($N_{f}$), unit cell shape, and the contribution factor (K), a new equation for bending rigidity is derived. The closer the bonding point is, the more the fibers between adjacent bonding points are likely to behave with no freedom. This fact is relevant to the contribution factor which is the relative contribution portion to bending rigidity and can be determine from the reconfigured bond area and unit cell. The experimental bending rigidity is more dependent on theoretical bending rigidity of the no freedom region than that of the complete freedom region. In general, the theoretical and experimental values of bending rigidity of the nonwoven fabrics show considerably good agreement.

Studies on Characteristics of Torsional Rigidity on Single Spun Yarns(I) -Theoretical- (방적단사의 비틀림 강성의 특성에 관한 연구(I) - 이론-)

  • Kim, Seung-Jin;Lee, Jae-Gon;Gang, Tae-Jin
    • Textile Science and Engineering
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    • v.26 no.3
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    • pp.51-64
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    • 1989
  • The torsional rigidity of spun yarn is derived in terms of physical and mechanical characteristics of its constituent fibres and yarn structural parameters to investigate its torsional behavior. The torsional rigidity of spun yarn increases with fibre length, shear modulus and the ratio of bending rigidity to the torsional rigidity of its constituent fibres. Maximum yarn torsional rigidity was obtained with increasing yarn surface helix angle. However, the theoretical torsional rigidity of the spun yarn increases with the coefficient of interfibre friction.

A Study on the Torsional Behavior of 2-ply Multifilament Yams(I)-Theoretical Analysis on the Torsional Rigidity- (2합 멀티필라멘트사의 비틀림거동에 관한 연구(I) -비틀림강성의 이론적 고찰-)

  • Park, Jeong-Hwan;Kim, Deok-Ri;Kim, In-Hyeon
    • Textile Science and Engineering
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    • v.32 no.7
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    • pp.661-671
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    • 1995
  • The theoretical torsional rigidity of 2-ply multifilament yam is derived in terms of mechanical values of its constituent filaments and yarn structural parameters as follows. Theoretical analysis shows that the specific torsional rigidity of 2-ply multifilament yarn increases with the ratio, Ψ of the filament torsional rigidity to the bending rigidity at low plying helix angle, but it decreases with the ratio at high Plying helix angle. The maximum specific torsional rigidity of 2-ply multifilament yam was observed with increase of plying helix angle at the low value of 9, but the torsional rigidity of it decreases with increase of plying helix angle at the high value of Ψ.

The Study on Rigidity Index of the Soft Clay in Korea (국내 연약지반의 강성지수(Ir)에 관한 연구)

  • 서수봉;윤일형;이재식;구남실
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.49-54
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    • 2000
  • Several soil parameters can be calculated for results of Piezocone test; sensitivity, soil classification, OCR, undrained shear strength, coefficient of consolidation etc., and used to analysis geotechnical problems. Particularly, the coefficient of consolidation which is related to degree of consolidation varies according to rigidity index(I/sub r/). In this study, rigidity index(I/sub r/) was analyzed by Roy's formula. Trixial tests and unconfined compression tests data in the ten sites was analyzed. In conclusion, rigidity index(I/sub r/) was suggested such as rigidity index(I/sub r/) = 15∼60, average rigidity index value(I/sub r/) of approximately 33 within a country.

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Nominal Wage Rigidity and Employment Volatility (명목임금의 경직성과 고용변동성)

  • Hwang, Sanghyun;Lee, Jin-Young
    • Asia-Pacific Journal of Business
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    • v.10 no.4
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    • pp.137-151
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    • 2019
  • Using Korean Labor and Income Panel Study data, this paper estimates nominal wage rigidity in Korea by industry from 2005 to 2017 and evaluates the level of inefficiency of Korean labor market. And, after estimating employment volatility by industry using the Labor Force Survey at Establishments data for Korea, we combine the nominal wage rigidity and the employment volatility estimates and analyze the effect of nominal wage rigidity on employment volatility in Korea from 2011 to 2017. If the level of wage rigidity is high, it may be hard for the labor market to be in the equilibrium, and therefore, the market may have inefficiency. We find that the inefficiency of the labor market in Korea have increased from 2005 to 2017 and the industry of accommodation and food service activities has the highest level of inefficiency over the period. We also find that one-percent-point increase in wage rigidity increases employment volatility by 2.3-2.9 percent and the positive effect is bigger for workers with part-time and temporary jobs. The result implies that firms may adjust their labor costs by changing the number of casual workers, rather than permanent workers, when the labor market suffers from a high level of wage rigidity.

A Study on Buckling Characteristics of 2-way Grid Single-Layer Domes Considering Rigidity-Effect of Roofing Covering Materials (지붕마감재 강성효과를 고려한 2방향 그리드 단층돔의 좌굴특성에 관한 연구)

  • Park, Sang-Hoon;Suk, Chang-Mok;Jung, Hwan-Mok;Kwon, Young-Hwan
    • Journal of Korean Association for Spatial Structures
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    • v.2 no.1
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    • pp.85-92
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    • 2002
  • Two way grid single-layer domes are of great advantage in fabrication and construction because of the simple fact that they have only four members at each junction. But, from a point of view of mechanics, the rectangular latticed pattern gives rise to a nonuniform rigidity-distribution in the circumferential direction. If the equivalent rigidity is considered in the axial direction of members, the in-plane equivalent shearing rigidity depends only on the in-plane bending rigidity of members and its value is very small in comparison to that of the in-plane equivalent stretching rigidity. It has a tendency to decrease buckling -strength of dome considerably by external force. But it is possible to increase buckling strength by the use of roofing covering materials connected to framework. In a case like this, shearing rigidity of roofing material increases buckling strength of the overall structure and can be designed economically from the viewpoint of practice. Therefore, the purpose of this paper, in Lamella dome and rectangular latticed dome that are a set of 2-way grid dome, is to clarify the effects of roofing covering materials for increasing of buckling strength of overall dome. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems. The conclusion were given as follows: 1. In case of Lamella domes which have nearly equal rigidity in the direction of circumference, the rigidity of roofing covering materials does not have a great influence on buckling-strength, but in rectangular latticed domes that has a clear periodicity of rigidity, the value of its buckling strength has a tendency to increase considerably with increasing rigidity of roofing covering materials 2. In case of rectangular latticed domes, as rise-span-ratio increases, models which is subjected to pressure -type-uniform loading than vertical-type-uniform loading are higher in the aspects of the increasing rate of buckling- strength according to the rate of shear reinforcement rigidity, but in case of Lamella dome, the condition of loading and rise-span-ratio do not have a great influence on the increasing rate of buckling strength according to the rate of shear reinforcement rigidity.

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