• Title/Summary/Keyword: bar structure

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Bond Stress of the Bar Removed Rust with Concrete (전식녹을 제거한 철근과 콘크리트의 부착응력에 관한 실험적 연구)

  • Choi, Hyo-Seok;Lee, Joo-Il;Ryu, Soo-Hyun;Yu, Ho-Hyun;Kim, Jin-Mu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.5 no.1
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    • pp.188-194
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    • 2001
  • A reinforced concrete structure is complex structure that works as one body with bonding role of steel bar and concrete. The bonding action between steel bar and concrete makes possible the compound structure. The transmission of mutual strength of the steel bar with concrete in structure is determined by the bonding characteristic of steel bar and concrete surface. But the efficiency of bonding characteristic of steel bar is Questionable by the corrosion cause by the delay construction term, the wrong management, etc. So this study investigate bonding characteristic of reinforced concrete using pull-out test method which steel bar removed rust and the principal variables of this study are concrete compression strength and the degree of corrosion. The result showed that bonding strength tend to increase when removed rust of steel bar whereas it tend to decrease when not removed rust.

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The study of the effects to the structure borne noise in terms of the Anti-Roll Bar's mounting position (앤티롤바의 취부위치에 따른 철도차량의 실내소음에 대한 연구)

  • Park, Hee-Jun;Woo, Kwan-Je
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1794-1798
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    • 2008
  • Inside noise level of a running train in open field is the summation of air borne noise and structure-borne noise. Anti-roll bar is the major transmission path of vibration from bogie. And this vibration gives an effect to the structure borne noise. In this paper, the effect of anti-roll bar is investigated. Structure borne noise is analyzed in terms of changing the mounting position of anti-roll bar to reduce inside noise levels.

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A THREE DIMENSIONAL PHOTOELASTIC STRESS ANALYSIS OF IMPLANT-SUPPORTED MANDIBULAR OVERDENTURE ACCORDING TO IMPLANT NUMBER AND ATTACHMENT TYPE (임플란트의 수와 어태치먼트의 종류에 따른 하악 임플란트 지지 오버덴춰의 삼차원 광탄성 응력분석)

  • Han, Sang-Hoon;Tae, Yoon-Sup;Jin, Tae-Ho;Cho, Hye-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.35 no.3
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    • pp.577-608
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    • 1997
  • The purpose of this study is to evaluate the stress distribution in the bone around dental implants supporting mandibular overdenture according to the number of implant and the type of attachment. Two or four implants were placed in an edentulous mandibular model and three dimensional photoelastic stress analysis was carried out to measure the fringe order around the implant supporting structure and also to calculate principal stress components at cervical area of each implant. The attachments tested were rigid and resilient type of Dolder bar, Round bar, Hader bar and Dal-Ro attchment. The results were as follows ; 1. In 2-implant supported overdenture using Round bar, Hader bar, and Dal-Ro attachment, compressive stress pattern was observed on the supporting structure of implant on loaded side, while tensile stress pattern in unloaded side. 2. In 2-implant supported overdenture using Dolder bar, the rigid Dolder bar shared the occlusal loads between 2 implants in a more favorable manner than was exhibited by the resilient type, while the resilient type placed a more stress on the distocervical area of the implant on the loaded side. But compressive stress pattern was observed in both the loaded and unloaded sides in either case. 3. In 2-implant supported overdenture, rigid and resilient type of Dolder bar exhibited more cross arch involvement than the Round bar, Hader bar, or Dal-Ro attachment. 4. In 4-implant supported overdenture using resilient Dolder bar and Hader bar, stress turned out to be distributed evenly among the implants between loaded and unloaded side, but thor was no reduction in the magnitude of the stress in the surrounding structure of implant contratry to 2-implant supported overdenture. 5. The stress pattern at cervical area of implant was different with the number of implant or the type of attachment but the overload, harmful to surrounding structure of implant, was not observed.

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The Structure of the Theory of Three Natures from the Hermeneutic Perspective of "the Three Turns of the Dharma Cakra" ('3전법륜설'의 해석학적 지평으로 본 삼성설의 구조)

  • Kim, Jae-gweon
    • Journal of Korean Philosophical Society
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    • v.117
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    • pp.35-55
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    • 2011
  • This article purports to clarify the doctrinal characteristics of the $Yog{\bar{a}}c{\bar{a}}ra$ school's hermeneutic interpretations of the "theory of the three turns of the Dharma Cakra" in the Saṃdbinirmocana-sūtra through early Indian $Yog{\bar{a}}c{\bar{a}}ra$ treatises such as the $Yog{\bar{a}}c{\bar{a}}rabb{\bar{u}}mi-vy{\bar{a}}kby{\bar{a}}$ and the. $Vy{\bar{a}}khy{\bar{a}}yukti$. It will probe how these interpretations apply co the theory of two truths or that of three natures($trisvabh{\bar{a}}va$) among the main doctrines of the $Yog{\bar{a}}c{\bar{a}}ra$ school. Especially, the peculiar characteristic of the "theory of the three turns of the Dharma Cakra" is such chat the thought of ${\acute{s}}{\bar{u}}nyat{\bar{a}}$ in the lineage of $Praj{\bar{n}}{\bar{a}}p{\bar{a}}ramita-s{\bar{u}}tras$ is regarded as incomplete, as the early school of Madhyamaka represented by $N{\bar{a}}g{\bar{a}}rjuna$ is conceived of as belonging to the second period of turn. Speaking of the further details of the "theory of the three turns of the Dharma Cakra", the $Yog{\bar{a}}c{\bar{a}}ra$ school subdivides the realm of saṃvṛti satya in $N{\bar{a}}g{\bar{a}}rjuna^{\prime}s$ theory of two truths; that is, it divides the saṃvṛti into merely linguistic existence and actual existence, and the thus-created structure of the theory of three natures on the basis of ocher-dependent nature(paratantra-$svabh{\bar{a}}va$) makes it possible to establish the doctrinal system of the thought of ${\acute{s}}{\bar{u}}nyat{\bar{a}}$ that is not subject to "nihilism or ${\acute{s}}{\bar{u}}nyat{\bar{a}}$ attached to evil." In effect, the above hermeneutic interpretation of the "theory of the three turns of the Dharma Cakra" is inherited into the structure of the $abh{\bar{u}}taparikalpa$ in the $Madhy{\bar{a}}nta-vibh{\bar{a}}ga$ so that, as seen in the commentary of Sthiramati, it is ascertained to apply to later doctrines through its secure establishment. To summarize its characteristics succinctly, firstly the $abh{\bar{u}}taparikalpa$ newly established as a saṃvṛti-satya is set up as the other-dependent nature, which is seen to have been set up particularly in order to sublate both the $Sarv{\bar{a}}stiv{\bar{a}}da^{\prime}s$ realist "view of being" and the Madhyamaka's "view of ${\acute{s}}{\bar{u}}nyat{\bar{a}}$" that impairs the ocher-dependent nature as a samvṛti-satya. In other words, according to the five kinds of views suggested in Sthiramati's commentary, the three natures are seen to be presented as the fundamental truth in order to unify all the doctrinal systems available ever since the beginning of Buddhism. Then, the theory of three natures is established principally on the basis of the $abh{\bar{u}}taparikalpa$, while the two truths of the $Yog{\bar{a}}c{\bar{a}}ra$ school are clearly ascertained to have been embedded in the structure of the $abh{\bar{u}}taparikalpa$. In fact, this might be understood to reflect the unique ontological view of reality or truth in the $Yog{\bar{a}}c{\bar{a}}ra$ School.

A Study on the Structural Properties of Composite Beam with Attaching Method of Main Bar of Different Types of Structure. (이질구조부 보주근 정착방법에 따른 혼합구조보의 구조적 특성에 관한 연구)

  • 김상헌;임병호;이승조;박정민;김화중
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.121-126
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    • 2000
  • The attaching method of different types of structure and explanation of stress transfer mechanism are at important issue as beam having definitive factor such as the anchorage of RC main bar, the stress transfer of anchorage-end S member, RC member-anchorage, anchorage-end S member in the composite beam of S and RC member. In this study, the structural properties of composite beam according to attaching method of main bar about end RC-middle S beam were investigated in order to use them as fundamental data for the development of composite structure member. Throughout a series of study, it was shown that the proof stress of main bar - flange welding specimen is the highest and there is no difference between the deformation-properties according to attaching method of main bar.

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Mock-up Test for Nuclear Power Plant Rebar Modulation Applying Febrication (선조립공법을 활용한 원전구조물 철근모듈화 Mock-up 실험연구)

  • Lim, Sang-Jun;Lee, Byung-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.13-14
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    • 2015
  • To minimize construction of nuclear facility, it is required to reduce reinforcing bar amount and solve reinforcing bar concentration and for this, it is necessary to develop appication design technology and modular of high strength reinforcing bar. Hence, KHNP reduces excessive reinforcing bar amount which can cause possibility of poor construction of concrete through design standard development and modular of nuclear facility structure using high strength reinforcing bar to raise economics and has its purpose to maintain high-level safety and durability as they are. After reviewing the rebar drawing of the NPP structures and performing the mock-up test, the rebar modulation method in the various area of the NPP Structure has been established.

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A Comparative Analysis of the Kinetic Structure in Lectures on a High School Science (고등학교 공통 과학 강의에서 교사에 따른 역동적 구조의 정량적 비교 분석)

  • Yu, Seung-Geun;Lee, Joon-Sang
    • Journal of The Korean Association For Science Education
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    • v.20 no.4
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    • pp.505-509
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    • 2000
  • The kinetic structure of the content of instructions at the unit of 'heart and circulation' in "the common science", which was respectively given by two teachers majored in biology and two teachers majored in earth science was investigated. Concerning of the mean of the fundamental coefficient (B1), the mean of weighted coefficients (B2) and the progression of instruction (P), T4 (B1, 0.14; B2, 0.82; P; 0.86) teacher showed relatively lower kinetic structure and faster progression than those of the others. The other teachers showed a different level of the kinetic structure and progression: T1(B1, 0.21; B2, 0.86; P; 0.79), T2 (B1, 0.02; B2, 0.85; P; 0.80), and T3 (B1, 0.22; B2, 0.83; P; 0.78). T1 teacher who showed the largest total frequency of verbal elements, the great number of sorts of verbal elements and secondary span, had a higher level of the kinetic structure, but T4 teacher showed the lowest level of total frequency of verbal elements, the great number of sorts of verbal elements and secondary span. The main reason why T4 teacher's instruction achieved a lower level of kinetic structure was estimated that he neglected to reorganize teaching materials and he showed a small number of discourse units. In addition, the unit of 'heart and circulation' was less related to T4 teacher's major and T4 teacher had a shorter teaching experience than those of the others. T4 teacher also took charge of only one class, and this did not allow to instruct repeatedly.

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An experimental study on the operation mode of rapid flooding protection system in tunnel (축소모형실험을 통한 터널 내 급속침수 차폐자동화 시스템 작동형태에 대한 연구)

  • Kim, Yeon-Deok;Kong, Min-Teak;Hwang, Beoung-Hyeon;Kim, Sang-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.6
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    • pp.1147-1159
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    • 2018
  • This study focuses on the verification of a rapid protection automation system using an inflatable structure. The inflatable structure is an automatic rapid protection system against human and material damage when the subsea tunnel is flooded. Especially, it is essential for construction and operation of subsea tunnels. In this study, we have experimentally verified the rapid protection automation system using the inflatable structure designed for this problem. In order to verify this, a model tunnel with a 40: 1 reduction ratio was constructed, and air pressure of 0.1 bar and 0.15 bar was injected to divide the tunnel according to the expansion rate at 10 sec and 20 sec. According to the results of the study, the protection efficiency was better at 0.15 bar than 0.1 bar when the expansion structure was expanded, and the protection efficiency and influent control efficiency were different according to the pneumatic injection time of the inflating structure. As a result of this study, it was found that the higher the internal air pressure of the inflated structure and the faster the inflation of rate, the more effectively the inflated structure was inflated. As a result of this study, it is necessary to further study the wedge type structure which is useful for the storage method of expansion structure, shape and expansion derivative, inhibition of expansion structure during protection and control of inflow water.

The Study on the Development of Automatic Rebar Placement System Applying Selection Method of Optimum Reinforcing Bar Group on Shear Wall (최적배근그룹 선정방법을 적용한 전단벽체의 자동배근 시스템 개발에 관한 연구)

  • Cho, Young-Sang;Kim, Dong-Eun;Jin, Hyun-Ah;Jang, Hyun-Suk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.1
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    • pp.81-89
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    • 2015
  • This study takes shear wall of reinforced concrete structure as study object, and the purpose of this study is to suggest structure BIM based on automatic reinforcing bar placement system applying set-based design through the most optimum reinforcing bar placement group that was selected by applying AHP (analytical hierarchy process) method from design step. For this, the most optimum reinforcing bar placement group was selected by pairwise comparison analysis on complex standard of multiple alternatives. And shear wall automatic reinforcing bar placement system has been developed, which can automatically generate members and arrange reinforcing bar by structure design algorithm and using open API (application programming interface) provided by a BIM software vendor. As a result, the most optimum reinforcing bar placement group of the highest weight, ALT1, was selected and was generated using Tekla Structure program.

Thermal Stress Relief through Introduction of a Microtrench Structure for a High-power-laser-diode Bar (높은 광출력을 갖는 Laser Diode Bar의 열응력 개선: 마이크로-홈 도입을 통한 응력 분포 변화 분석)

  • Jeong, Ji-Hun;Lee, Dong-Jin;O, Beom-Hoan
    • Korean Journal of Optics and Photonics
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    • v.32 no.5
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    • pp.230-234
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    • 2021
  • Relief of thermal stress has received great attention, to improve the beam quality and stability of high-power laser diodes. In this paper, we investigate a microtrench structure engraved around a laser-diode chip-on-submount (CoS) to relieve the thermal stress on a laser-diode bar (LD-bar), using the SolidWorks® software. First, we systematically analyze the thermal stress on the LD-bar CoS with a metal heat-sink holder, and then derive an optimal design for thermal stress relief according to the change in microtrench depth. The thermal stress of the front part of the LD-bar CoS, which is the main cause of the "smile effect", is reduced to about 1/5 of that without the microtrench structure, while maintaining the thermal resistance.