• Title/Summary/Keyword: Lateral-Support

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Infilled frames: developments in the evaluation of cyclic behaviour under lateral loads

  • Cavaleri, L.;Fossetti, M.;Papia, M.
    • Structural Engineering and Mechanics
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    • v.21 no.4
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    • pp.469-494
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    • 2005
  • In order to consider the modified seismic response of framed structures in the presence of masonry infills, proper models have to be formulated. Because of the complexity of the problem, a careful definition of an equivalent diagonal pin-jointed strut, able to represent the horizontal force-interstorey displacement cyclic law of the actual infill, may be a solution. In this connection the present paper, continuing a previous work in which a generalised criterion for the determination of the ideal cross-section of the equivalent strut was formulated, analizes some models known in literature for the prediction of the lateral cyclic behaviour discussing their field of validity. As a support of the discussion, the results of an experimental investigation involving single story-single bay infilled reinforced concrete. Frames under vertical and lateral loads with different kind of infill (actually not yet so much investigated) are presented. Finally, an improvement of a model known in the literature is proposed, taking the results of the experimental tests before mentioned into account.

Drift Control for Multistory Moment Frames under Lateral Loading

  • Grigorian, Carl E.;Grigorian, Mark
    • International Journal of High-Rise Buildings
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    • v.2 no.4
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    • pp.355-365
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    • 2013
  • The paper reports results of recent studies on the effects of column support conditions on the lateral displacements of moment frames at incipient collapse. The article presents a number of exercises in the plastic theory of structures that lead to useful design formulae. It has been shown that Drift Shifting (DS) is caused due to differences in the stiffnesses of adjoining columns, and that changes in drift ratios are more pronounced at first level column joints in both fixed as well as pinned base frames. In well proportioned moment frames, DS in the upper levels could be minimized, even reduced to zero. It has been demonstrated that DS can be eliminated in properly designed fixed and grade beam supported (GBS) moment frames. Several examples, including symbolic P-delta effects, have been provided to demonstrate the validity and the applications of the proposed ideas to the design and drift control of moment frames. The proposed methodology is exact within the bounds of the theoretical assumptions and is well suited for preliminary design and teaching purposes.

A Study of Coupled Motion in Football, Baseball Players and General Students in Thoracic Spine

  • Moon, Ok Kon
    • Journal of International Academy of Physical Therapy Research
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    • v.3 no.2
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    • pp.464-468
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    • 2012
  • The objective of this study is to provide basic information on coupled motions in thoracic spine during lateral bending from a neutral position for football and baseball players as well as for general university students. In the experiment, a total of 30 subjects participated(football players: 10, baseball players: 10, general students: 10). All subjects were in their 20's. The subjects sat on a chair with lumbar support in a neutral position and bent to the right. As a result, for baseball players, coupled motions were observed in the opposite direction of the lateral bending in all parts of thoracic spine. For both football players and general students, coupled motions were observed in the same direction. These results confirmed that unilateral movements like baseball could affect coupled motions.

Effects of tube-support parameters on damping of heat exchanger tubes in liquids (튜브지지대 인자가 열교환기 튜브의 감쇠에 미치는 영향)

  • 김범식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.5
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    • pp.1003-1015
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    • 1988
  • Damping information is required to analyse heat exchangers for flow-induced vibration. The most important energy dissipation mechanisms in heat exchanger tubes are related to the dynamic interaction between tube and support. In liquids, squeeze-film damping is dominat. Simple experiments were carried out of a two-span tube with one intermediate support to investigate the effects of tube-support parameters, such as: tube-support thickness, diametral clearance, tube eccentricity, tube span length, location of tube-support, and nature of dynamic interaction between tube and tube-support. The results show that squeeze-film damping is much larger for lateral-type motion than for rocking-type motion at the support. Eccentricity was found to be very important. Diametral clearance, support thickness and frequency are also very relevant. The effects of these parameters on squeeze-film damping are formulated and proposed in a semi-empirical expression.

Effect of Relative Density on Lateral Load Capacity of a Cyclic Laterally Loaded Pile in Sandy Soil (모래지반의 상대밀도에 따른 횡방향 반복재하 시 말뚝의 극한지지력 평가)

  • Baek, Sung-Ha;Kim, Joon-Young;Lee, Seung-Hwan;Chung, Choong-Ki
    • Journal of the Korean Geotechnical Society
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    • v.32 no.4
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    • pp.41-49
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    • 2016
  • Pile foundations used as offshore support structures are dominantly subjected to cyclic lateral loads due to wind and waves. In this study, a series of cyclic lateral load tests were performed on a pre-installed aluminum flexible pile in sandy soil with three different relative densities (40%, 70% and 90%) in order to evaluate the effect of cyclic lateral loads on lateral load capacity of a pile. The cyclic lateral loads increased the lateral load capacity of a pile at 40% relative density, whereas they decreased it at 70% and 90% relative densities. This can be explained by the fact that the cyclic lateral loads slightly densified the surrounding soil in relatively loose sand (40%), while the surrounding soil was disturbed in relatively dense sand (70% and 90%). These effects were more obvious as the cyclic lateral load amplitude increased, being independent with the saturation. Also, from the test results, an empirical equation for the lateral load capacity of a cyclic laterally loaded pile in sandy soil was developed in terms of relative density of the soil and the cyclic lateral load amplitude.

A Study on Improvement of Aircraft Handling Quality for Asymmetric Loading Configuration from Flight Test (비행시험을 통한 비대칭 무장 형상의 조종성 개선에 관한 연구)

  • Kim Chong-Sup;Hwang Byung-Moon;Kim Seung-Jun
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.7
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    • pp.713-718
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    • 2006
  • Supersonic jet fighter aircraft have several different weapon loading configuration to support air-to-air combat and air-to-ground delivery of weapon modes. Especially, asymmetric loading configurations could result in decreased handling qualities for the pilot maneuvering of the aircraft. The design of the T-50 lateral-directional roll axis control laws change from beta-betadot feedback structure to simple roll rate feedback structure and gains such as F-16 in order to improve roll-off phenomena during pitch maneuver in asymmetric loading configuration. Consequently, it is found that the improved control law decreases the roll-off phenomenon in lateral axes during pitch maneuver, but initial roll response is very fast and wing pitching moment is increased. In this paper, we propose the lateral control law blending between beta-betadot and simple roll rate feedback system in order to decreases the roll-off phenomenon in lateral axes during pitch maneuver without degrading of roll performance.

Performance of Innovative Prestressed Support Earth Retention System in Urban Excavation (도심지 굴착에 적용된 IPS 흙막이 구조물의 현장거동)

  • Kim Nak Kyung;Park Jong Sik;Jang Ho Joon;Han Man Yop;Kim Moon Young;Kim Sung Bo
    • Journal of the Korean Geotechnical Society
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    • v.21 no.2
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    • pp.27-36
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    • 2005
  • The performance of innovative prestressed support (IPS) earth retention system applied in urban excavation was presented and investigated. The IPS wales provide a high flexural stiffness to resist the bending by lateral earth pressure, and the IPS wales transfer lateral earth pressure to Corner struts. The IPS wale provides a larger spacing of support, economical benefit, construction easiness, good performance, and safety control. In order to investigate applicability and stability of the IPS earth retention system, the IPS system was instrumented and was monitored during construction. The IPS system applied in urban excavation functioned successfully. The results of the field instrumentation were presented. The measured performances of the IPS earth retention system were investigated and discussed.

A New Lane Departure Warning System using a Support Vector Machine Classifier and a Fuzzy System

  • Kim, Sam-Yong;Oh, Se-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.110.3-110
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    • 2002
  • $\textbullet$ Lane detection by TFALDA $\textbullet$ SVM for large scale data and multiclass classification problem $\textbullet$ TLC Classification $\textbullet$ Lateral offset estimation by IPT $\textbullet$ Lane departure warning by a fuzzy system $\textbullet$ Experimental results by HiLS $\textbullet$ Conclusion

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Bending Behavior of Nailed-Jointed Cross-Laminated Timber Loaded Perpendicular to Plane

  • Pang, Sung-Jun;Kim, Kwang-Mo;Park, Sun-Hyang;Lee, Sang-Joon
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.6
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    • pp.728-736
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    • 2017
  • In this study, the bending behavior of cross-laminated timber (CLT) connected by nails were investigated. Especially, the load-carrying capacity of the nail-jointed CLT under out-of-plane bending was predicted by the lateral resistance of the used nails. Three-layer nail-jointed CLT specimens and a nail connection were manufactured by 30 mm (thickness) ${\times}$ 100 mm (width) domestic species (Pinus koraiensis) laminas and Ø$3.15{\times}82mm$ nails using a nail-gun. Shear test for evaluating the nail lateral resistance and bending test for evaluating the load-carrying capacity of the nail-jointed CLT under out-of-plane bending were carried out. As a result, two lateral resistance of the used nail, the 5% fastener offset value and the maximum value, were 913 N and 1,534 N, respectively. The predicted load-carrying capacity of the nail-jointed CLT by the 5% offset nail lateral resistance was similar to the yield points on the actual load-displacement curve of the nail-jointed CLT specimens. Meanwhile, the nail-jointed CLT specimens were not failed until the tension failure of the bottom laminas occurred beyond the maximum lateral resistance of the nails. Thus, the measured maximum load carrying capacities of the nail-jointed CLT specimens, approximately 12,865 N, were higher than the predicted values, 7,986 N, by the maximum nail lateral resistance. This indicates that the predicted load-carrying capacity can be used for designing a structural unit such as floor, wall and roof able to support vertical loads in a viewpoint of predicting the actual capacities more safely.

Theoretical and experimental analysis of the lateral vibration of shafting system using strain gauges in 50,000-DWT oil/chemical tankers (스트레인 게이지를 이용한 5만 DWT 석유화학제품 운반선의 횡진동 분석에 관한 연구)

  • Lee, Jae-Ung
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.4
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    • pp.301-306
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    • 2016
  • During the initial stage of propulsion shaft design, the shaft alignment process includes a thorough consideration of lateral vibration to verify the operational safety of the shaft. However, a theoretical method for analyzing forced lateral vibrations has not been clearly established. The methods currently used in classification societies and international standards can only ensure a sufficient margin to avoid the blade-passing frequency resonance speed outside the range of ${\pm}20%$ of the maximum continuous rating (MCR) for the engine. Typically, in shaft alignment analyses, longer center distances between the support bearings promote affirmative results, but the blade order resonance speed can approach the lower limit for lateral vibration. Therefore, this matter requires careful attention by engineers, and a verification of the theoretical analysis by experimental measurements is highly desirable. In this study, both theoretical and experimental analyses were conducted using strain gauges under two draught conditions of vessels used as 50,000-DWT oil/chemical tankers, introduced recently as eco-friendly ships. Based on the analyses, the influence of the lateral vibration on the shafting system and the system's reliability was reviewed.