• Title/Summary/Keyword: 구조벽

Search Result 1,090, Processing Time 0.024 seconds

Comparative Studies on the structure of the Coelomic walls of the Korean Terrestrial Slugs(Limax flavus Incilaria fruhstorferi) (한국산 육생 민달팽이류(Limax nauus와 Incilaria fruhstoneri) 체강벽의 구조에 관한 비교 연구)

  • 장남섭
    • The Korean Journal of Zoology
    • /
    • v.34 no.3
    • /
    • pp.368-381
    • /
    • 1991
  • 한국산 육생민달팽이유(Limaxpouus와 상ciluria hhstoferi)의 체강벽을 배측부, 복측부 및 외투천 등 3부분으로 나누어 관찰하였으며, 그 결과는 다음과 같다. 1, Limaxpouus의 배측부 체강벽은 많은 모지상돌기 형 태의 근조직과 체강벽상피세포로 구성되어 있으나, 복측부 체강조은 많은 수의 중성점액질 형성세포와 근섬유들로만 형성되었다. 2. Incilaria hhstoferi의 배측부와 복측부는 공히 중성점액질 형성세포와 근섬유들로만 형성되고, 체강상피세포는 관찰되지 않았다. 3. Incilorlo jruhstor$\ulcorner$sri의 병투막측 체준벽은 불규칙한 모양의 단층 체강상피세포와 많은 근섬유로 구성되었다.

  • PDF

Shear Performance of Post and Beam Construction by Pre-Cut Process (프리컷 방식을 적용한 기둥-보 공법의 수평전단내력)

  • Hwang, Kweonhwan;Park, Joo-Saeng;Park, Moon-Jae
    • Journal of the Korean Wood Science and Technology
    • /
    • v.35 no.6
    • /
    • pp.1-12
    • /
    • 2007
  • For the purpose of effective utilization of domestic second-grown larch as structural members, post and beam construction applying traditional construction to Japanese larch glulam members was adopted with processing by machine pre-cut method. In general, horizontal shear test by KS F 2154 is conducted to assess the horizontal shear properties of the wooden structure by post and beam construction. The frame was consisted of post and beam member with appropriate fasteners, and members have their own processed parts (notch, hole, etc.) that can be well-connected each other. The shear wall was consisted of the frame with screw-nail sheathed panel (OSB). The results of horizontal shear loading tests without vertical loads conducted on the frame and the shear wall structures, the maximum strengths were about 1.9 kN/m and about 9.7 kN/m, the shear rigidities were about 167 kN/rad, 8198 kN/rad, respectively. The strength proportion of the frame specimen was about 20% of the wall's and about 2% in initial stiffness. Nail failures are remarkable on the shear wall specimen with punching shears and shear failures. The shear load factor for the shear wall specimen by the method of Architectural Institute of Japan was 1.5, which was obtained by the bi-linear method. Loading method should be considered to obtain smooth load-deformation relationship. For the better shear performance of the structures, column base and post and beam connections and sheathed panel should be further examined as well.

Performance Evaluation of Laminated-Tempered Glass as a Component of Noise Barrier on Metro Railway Elevated Bridge Against Train Induced Vibration and Wind Load (지하철 고가교 접합강화유리 방음판의 열차진동 및 풍하중에 대한 성능평가)

  • Kim, Suk-Su;Lee, Ho-Beom;Song, Jae-Ho
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.21 no.5
    • /
    • pp.30-41
    • /
    • 2017
  • Types of noise barrier installed for noise attenuation are largely divided into noise-absorbing format and noise-proofing format. In these days, installation of transparent noise barrier is general trend to solve problems that hinder sunshine and landscape. Some kinds of transparent boards are used to one of components in noise barriers, but in some cases, less transparency and worse pollution due to yellowing phenomena, and severe material deformation are to harm the urban aesthetics Therefore laminated-tempered glass board in that yellowing phenomena does not occur can be replaced as a transparent one to secure those shortcomings. In this paper, the structural safety against train induced vibration and the resistibility to wind load are analyzed for laminated-tempered glass system as a component of noise barrier installed on Metro railway elevated bridges. Also the appropriateness is evaluated through flexural bending performance test, compressive strength test, modulus of elasticity tests, and impact test for the system or the glass material itself. All of these processes are intended to present the deployment of logic to evaluate the adequacy for the system.

A Special Purpose FE Program for the Collapse Strength Analysis of Bulk Carrier Corrugated Bulkheads Subject to Accidental Flooding (침수시 산적화물선 파형 횡격벽 붕괴강도해석 전용 유한요소 프로그램 개발)

  • Jeom-Kee Paik;Sung-Geun Kim
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.35 no.2
    • /
    • pp.63-73
    • /
    • 1998
  • Due to the collapse of corrugated bulkheads subject to accidental flooding which is thought to be a primary cause of bulk carrier losses International Maritime Organization(IMO), the International Association of Classification Societies(IACS) and the leading classification societies are taking a growing concern for the structural safety of corrugated bulkheads of bulk carriers. To prevent progressive collapse of corrugated bulkhead in flooded condition particularly of forward cargo ho1d they try to make rules which require reinforcement of corrugated bulkhead structure. However, we are still confronted with the urgent problem of more accurate and efficient ultimate strength assessment for corrugated bulkheads. This paper develops a special purpose nonlinear FE program for analyzing progressive collapse behavior of corrugated bulkheads subject to lateral pressure loads. As verification examples, the program is applied to collapse strength analysis of steel corrugated bulkhead test model.

  • PDF

Behavior of Three Story Bearing Wall Structure under Lateral toad Reversals (반복 수평하중을 받는 3층 철근콘크리트 내력벽 아파트 구조물의 거동 특성)

  • Chang Kuk-Kwan;Oh Young-Hun;Kim Ki-Hyun
    • Journal of the Korea Concrete Institute
    • /
    • v.16 no.5 s.83
    • /
    • pp.627-634
    • /
    • 2004
  • The purpose of this study is to investigate seismic performance of a bearing wall system for apartment buildings. An 1/3 scale three-story specimen was constructed and tested under cyclic lateral loads. The specimen was consisted of pierced walls and coupling elements as well as floor slabs. The bearing wall system is considered to have a adequate deformation capacity up to $2.0\%$ of roof drift ratio, and the experimental results showed the ductile load-deformation characteristics even though some walls were failed in shear Nonlinear analysis was peformed to compare the load-deformation curve obtained from the experimental program. The result of nonlinear analysis could be useful to predict the actual behavior characteristics of the bearing wall system subjected to lateral loads.

Study on Cracking Causes and Patterns in Median Barrier and Guardrail Concrete in RC Bridge (콘크리트 교량 방호벽의 균열원인 및 패턴 분석에 대한 연구)

  • Choi, Se-Jin;Choi, Jung-Wook;Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.18 no.5
    • /
    • pp.19-26
    • /
    • 2014
  • Concrete guide rail and median barrier are an attached RC member, however they are vulnerable to cracking due to slip form construction and large surface of member. In this study, causes and pattern of cracking are analyzed through assessment and NDT (Non-Destructive Technique) evaluation for concrete guide rail and median barrier on highway structure. For this work, analysis on drying shrinkage and hydration heat are performed considering installation period, and plastic shrinkage is also analyzed considering their environmental conditions. From the evaluation, plastic settlement around steel location, drying/ plastic shrinkage, and aggregate segregation are inferred to be the main causes of cracking in the structures. The crack causes and patterns are schematized and techniques of crack-control are suggested. Furthermore concrete guide rail/ median barrier in the bridge on the sea are vulnerable to cracking at early age so that special attentions should be paid at the stages of material selection and construction.

Shotcrete-Retrofit of Shear Walls with an Opening (개구부를 가지는 전단벽의 숏크리트 보강)

  • Choi, Youn-Cheul;Choi, Chang-Sik;Kim, Hyun-Min;Lee, Li-Hyung
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.11 no.5
    • /
    • pp.71-80
    • /
    • 2007
  • Because of the characteristics relating to high tensile ductility, High Performance Fiber Reinforced Cementitious Composites (HPFRCC) are studied to be adopted in repair and retrofit of buildings. A series of three shear wall specimens was tested under constant axial stress and reversed cyclic lateral loading in order to evaluate the seismic retrofit that had been proposed for the shear wall with the opening. The retrofit involved the use of newly developed ECC and MDF(Macro Defect Free), both of which are sprayed through the high pressure pump, over the entire face of the wall. The results indicate that two difference types of retrofitting strategy make the different effects of a rise in the strength and ductility of each specimen.