• Title/Summary/Keyword: Resistant force

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Effect of Caisson Tilting on the Sliding Distance of a Caisson under Wave Impacts and Introduction of the Effect into Computation of Sliding Distance

  • Kim, Tae Min;Takayama, Tomotsuka
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.474-478
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    • 2004
  • Based on the recent laboratory experiments (Kim et al. 2004), comparisons of caisson sliding distance are made between the computations and experiments. The time history model of wave force, which is proposed by Tanimoto et al. (1996), is modified in the standing wave part of horizontal and uplift wave forces because of the overestimation of the time history model. The comparison between experimental and computational sliding distance has showed that the caisson tilting increases the resistant force to the horizontal sliding. Therefore, a titling resistant force, which is caused by caisson tilting, is introduced into computation of sliding distance.

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MEASUREMENT AND ANALYSIS OF THE RESISTANT MUSCLE FORCE OF MEDIAL PTERYGOID MUSCLE IN THE MANDIBULAR PROGNATHIC PATIENTS (하악전돌증 환자에서 내측 익돌근 근력측정 및 분석)

  • Hong, Jong-Rak;Kang, Na-Ra;Choung, Pill-Hoon
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.30 no.2
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    • pp.131-135
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    • 2004
  • The purpose of this study was to evaluate the resistant force of medial pterygoid muscles against the mandibular advancement and distraction to anterior, and inquire into the relationship between medial pterygoid muscles and cephalometric variables. Sixty six patients with class III malocclusion underwent bilateral sagittal splitting of ramus with intraoralvertico-sagittal ramus osteotomy for mandibular set-back. The spring scale was used to measure the resistance of medial pterygoid muscles after splitting of ramus. Skeletaldental cephalometric analysis was made and statistic package was used for correlation between resistance and cephalometric variables. The resistant force of the right medial pterygoid muscle was greater than the left one in Koreans with class III malocclusion, and the force had a linear regression relationship with facial depth. The results suggested that facial depth has significant correlation with the resistance of medial pterygoid muscle, which can be acquired from patient's cephalometric analysis.

Wind-Resistant Safety Reviews of Cable-Stayed Bridge by Wind Tunnel Tests (풍동실험을 통한 사장교의 내풍 안전성 검토)

  • Huh, Taik-Nyung
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.4_2
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    • pp.637-644
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    • 2020
  • Because suicide accidents sometimes were happened in grand bridges over rivers or sea water recently, it will be necessary that prevention measures be made preparation in advance from now on. Additional safety facilities must be needed in addition to existing safety facilities in such a way as this prevention measure. In order to make cable-stayed bridge safe on wind for additional safety facilities, main girder models with added safety facilities for wind-tunnel tests was made, and wind tunnel experiments was carried out to measure aerodynamic force coefficients. Also, wind-resistant analyses of 3D cable-stayed bridge were performed on the basis of wind-tunnel test results. From the wind experiments, force coefficients of main girder with added safety facilities were assessed, and it is known that there are little possibility of galloping and rotation of steel main girder. Finally, from the wind resistant analyses, it was concluded that wind-resistant safety of cable-stayed bridge was secured on wind speed 60.6m/sec.

Design of Additional Tendon Force and Evaluation of Resistant Moment for Prestressed Concrete Composite Section (프리스트레스트 콘크리트 합성단면에 도입되는 추가 긴장력 설계와 저항모멘트 평가)

  • Yon Jung-Heum;Kim Do-Goon
    • Journal of the Korea Concrete Institute
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    • v.16 no.3 s.81
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    • pp.335-344
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    • 2004
  • A general composite section of precast and cast-in-place concrete with prestressed and nonprestressed reinforcements was analyzed to calculate residual stresses and loss of prestressing force caused by internal constraints of concrete long-term deformation. From the analytical results, equations to design additional prestressing force and to evaluate resistant moment of the composite section were proposed. The equations shows that the additional prestressing force can be over-estimated if the loss rate of the first prestressing force is over-estimated from the lumped sum of a design code. The analytical procedure with the proposed equations has been applied to a composite section using the AASHTO Type 5 girder. The loss rates of the additional prestressing force appling to the precast concrete girder was less than those appling to the composite girder. However, the resistant moment of the additional prestressing force on the composite girder was much larger than that on the precast concrete girder. The additional prestressing force appling to the composite section was very effective for strengthening of the prestressed concrete composite girder.

Analysis of the resistant muscle force against distraction in the maxilla-facial deformities (악안면 기형환자에서 내측 익돌근 근력측정 및 의미분석)

  • Choung Pill-Hoon;Hong Jong-Rak;Bae Yong-Chul
    • Korean Journal of Cleft Lip And Palate
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    • v.4 no.2
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    • pp.45-50
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    • 2001
  • Recents reports have demonstrated that force and direction is important during mandibular distraction osteogenesis. The purpose of this study was to evaluate the resistant force of internal pterygoid muscles and inquire into relationship between internal pte'Ygoid muscles and cephalometric parameters. Eighty four patients with class III malocclusion underwent bilateral sgittal splitting of ramus with intraoral vertico-sagittal ramal osteotomy. A spring scale were used for measuring for resistence of internal pterygoid mescles after splitting of ramus. Skeletal-dental cephalometric analysis was made following statistic package was used for correlation between resistence and cephalometric parameters. The resistant force of right internal pterygoid muscle was greater than left muscle in Korean with class III malocclusion and the force had a linear regression relationship with facial depth (distance between nasion and gonion). The results suggested that facial depth has significant correlation of the resistance of internal pterygoid muscle (p<0.05).

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Design for earthquake-resistant short RC structural walls

  • Zygouris, Nick St.;Kotsovos, Gerasimos M.;Kotsovos, Michael D.
    • Earthquakes and Structures
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    • v.8 no.3
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    • pp.713-732
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    • 2015
  • The application of the compressive force path method for the design of earthquake-resistant reinforced concrete structural walls with a shear span-to-depth ratio larger than 2.5 has been shown by experiment to lead to a significant reduction of the code specified transverse reinforcement within the critical lengths without compromising the code requirements for structural performance. The present work complements these findings with experimental results obtained from tests on structural walls with a shear span-to-depth ratio smaller than 2.5. The results show that the compressive force path method is capable of safeguarding the code performance requirements without the need of transverse reinforcement confining concrete within the critical lengths. Moreover, it is shown that ductility can be considerably increased by improving the strength of the two bottom edges of the walls through the use of structural steel elements extending to a small distance of the order of 100 mm from the wall base.

Experiments on the Resistant Force of the Trees in Rivers (하천 내 수목의 내력 시험)

  • Lee, Jin-Won;Yu, Dae-Yeong
    • Journal of Korea Water Resources Association
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    • v.30 no.3
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    • pp.211-223
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    • 1997
  • This study was focused on the investigation of the distribution of trees which is an important factor for the improvement of the river environment, and the experimental examination of resistant force of trees to the external forces. The investigation of plant distribution performed in 11 major rivers in Korea showed that the willow family grows spontaneously over the whole country. The field experiments on the resistant force of trees were carried out on the 78 trees of 8 species in 3 different sites to estimate whether pulled out trees damage downstream hydraulic structure. The experiments were performed by the method that a backhoe drew trees and the forces were measured when the trees were overturned and pulled out. The analysis of the experimental results showed that there is a linear correlation between the resistant force and DHB (diameter at breast height).

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Estimation of Machinability of Lead Brass Based on In-Situ Observation in Scanning Electron Microscope (전자현미경 In-Situ 관찰방법을 이용한 황동의 절삭성평가)

  • Jung, Seung-Boo;Lim, Ok-Dong;An, Seong-Uk
    • Applied Microscopy
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    • v.24 no.3
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    • pp.87-93
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    • 1994
  • In order to elucidate the machinability of lead brass, orthogonal machining experiment was conducted in SEM(Scanning Electron Microscope) equipped with a micro-machining device at a cutting speed of $7{\mu}m/s$ for brass containing 0.2 to 3wt% Pb. The microfactors (i.e., shear angle, contact length between chip and tool) were determined by in-situ observations. Machinability of brass containing lead is discussed in terms of the microfactors and the cutting resistant force tested by lathe cutting. The dynamic behavior of the chip formation of lead brass during the machining process was examined: The chips of lead brass form as a shear angle type. The shear angle increases with the content of lead in (6:4) brass. The pronounced effect of lead on the contact length between chip and tool was observed above 1% Pb. The cutting resistant force tested by lathe decreases remarkably with the lead content in brass. The observed microfactors are in close relation to the tested resistant force in macromachining.

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A Case Study on collapse and Reinforcement of Colluvial Deposit slopes in Kyeong-Nam Geo-Je area (경남 거제 지역 붕적토 사면의 붕괴 및 보강 사례 연구)

  • Jeong, Chang-Deok;Jang, Jeong-Wook;Park, Choon-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.870-877
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    • 2005
  • This study examined a case of collapse and reinforcement of the colluvial deposit slope in Kyeongnam Geoje Area. The reason for the collapse was found first in the reduction of the resistant force due to slope-cut for constructing retaining walls. This decreased the resistant force against sliding, which enabled precipitation during the rainy period to seep into the ground in the upper colluvium, resulting in increase in porewater pressure. This leads to decreased shear strength and increased sliding force, which ultimately caused the collapse of the slope. For the long-term stability, methods attained for stability reinforcement are summarized in the following table.

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Load-carrying Capacities of Safety Structures on Wind-resistant Analyses of Cable-stayed Bridge (사장교의 내풍해석을 통한 인명보호 구조물의 내하능력평가)

  • Huh, Taik-Nyung
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.4_2
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    • pp.587-594
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    • 2022
  • In the 2000s, a lot of cable-type grand bridges are being built in consideration of economic aspects such as the reduction of logistics costs and the distribution of traffic volume due to rapid economic development. In addition, because the recently installed grand bridges are designed in an aesthetic form that matches the surrounding environment as well as the original function of the road bridge, and serves as a milestone in an area and is used as an excellent tourism resource, attracting many vehicles and people, there is an urgent need for a safety structure that can ensure the safety of not only vehicles but also people. In order to make cable-stayed bridge safe on wind for additional five safety structures, main girder models with and without safety structures for wind-tunnel experiments was made, and wind tunnel experiments was carried out to measure aerodynamic force coefficients. Also, wind-resistant analyses of 3D cable-stayed bridge were performed on the basis of wind-tunnel experiment results. From the wind tunnel experiments for the aerodynamic force coefficients of main girder with five safety structures and the wind resistant analyses of cable-stayed bridge without safety structure and with safety structure, it was concluded that the best form of wind-resistant safety was shown in the order of mesh, standard, bracing, hollow, and closed type. And wind-resistant safety of cable-stayed bridge with hollow and closed type on design wind speed 68.0m/sec was not secured. Finally, as five safety structures are installed, maximum rate of stress increments was shown in the order of steel main beam, steel floor beam, concrete floor beam and cables.