• Title/Summary/Keyword: transverse

Search Result 4,761, Processing Time 0.028 seconds

An Experimental Study on Shear Strength of RCS System Beam-Column Jointswith Various Transverse Beam Sections (직교보 단면크기 변화에 따른 RCS구조 보-기둥 접합부의 전단내력에 관한 실험적 연구)

  • An, Jae-Hyeok;Park, Cheon-Seok
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.10 no.6
    • /
    • pp.197-204
    • /
    • 2006
  • Recently, in order to realization of construction and economical saving, various studies are progressing. Also, the study on RCS system which is consisted of reinforced concrete column and steel beam is progressing actively. Actually, however, resisting mechanism of panel zone is influenced by transverse beams when the stress transfers inner panel to outer panel but existing literature didn't reflect the effect of transverse beams. This paper is to analyze the test result of five inner beam-column joints specimen with a variable such as web, flange thickness of transverse beam and face bearing plate(FBP) for RCS systems were tested under cyclic loadings conforming to NEHRP recommendation to investigate the effect of transverse beams and the structural performance of beam-column joints. From the test result, it was shown that transverse beams are effective to enhance the shear strength and structural performance of beam-column joints.

The Volumetric Ratio of Transverse Reinforcement of R/C Columns Considering Effective Lateral Confining Reduction Factor (유효횡구속압력 감소계수를 사용한 RC 기둥의 횡보강근량 평가)

  • Kim, Jong-Keun;Ahn, Jong-Mun;Shin, Sung-Woo
    • Journal of the Korea Concrete Institute
    • /
    • v.21 no.3
    • /
    • pp.311-318
    • /
    • 2009
  • An experimental investigation was conducted to examine the hysteretic behaviors of ultra-high strength concrete tied columns. The purpose of this study is to propose the volumetric ratio of transverse reinforcement for ultra-high strength concrete tied columns with 100 MPa compressive strength. Nineteen 1/3 scaled columns were fabricated to simulate an 1/2 story of actual structural members with the main variables of axial load ratio, configurations and volumetric ratios of transverse reinforcement. The results show that the deformability of columns are affected by the configurations and volumetric ratios of transverse reinforcement. Especially, it has been found that the behavior of columns are affected by axial load ratio rather than the amounts and the configurations of transverse reinforcement. To improve the ductility behavior of RC column using ultra high strength concrete in a seismic region, We suggested the amount of transverse reinforcement for all data that satisfy the required displacement ductility ratio over 4. It is means that the lateral confining reduction factor (${\lambda}^c$) considering the effective legs, configuration and spacing of transverse reinforcement and axial load ratio was reflected for the volumetric ratio of transverse reinforcement.

Effects of Transverse Reinforcement on Headed Bars with Large Diameter at Cut-off Points (컷오프 구간에 정착된 대구경 확대머리철근에 대한 횡보강근의 효과)

  • Jung, Hyung-Suk
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.22 no.5
    • /
    • pp.82-90
    • /
    • 2018
  • The nuclear structures are composed of large diameter bars over No.36. If the hooked bars are used for anchorage of large diameter bars, too long length of the tail extension of the hook plus bend create congestion and make an element difficult to construct. To address those problems, headed bars were developed. Provisions of ACI 318-08 specify the development length of headed bars and ignore the effect of transverse reinforcement based on the background researches. However, if headed bars are used at the cut-off or lap splice, longitudinal reinforcements, which are deformed in flexural members, induce tensile stress in cover concrete and increase the tensile force in the transverse reinforcement. The object of this research is to evaluate the effects of transverse reinforcement on the anchorage capacity of headed bar so anchorage test with variable of transverse rebar spacing was conducted. Specimens, which can consider the behavior at the cut-off, were tested. Test results show that failure of specimen without transverse reinforcement was sudden and brittle with concrete cover lifted and developed stress of headed bars was less than half of yield strength of headed bars. On the other hand, in the specimen with transverse reinforcement, transverse rebar directly resist the load of free-end so capacity of specimens highly increased.

A Numerical Study on Characteristics of Smoke Exhaust in Road Tunnel Fires for Different Ventilation System (터널 화재 시 환기 방식에 따른 배연 특성의 수치해석 연구)

  • Kim, Jong-Yoon;Yoo, Ji-Oh
    • Fire Science and Engineering
    • /
    • v.22 no.3
    • /
    • pp.201-207
    • /
    • 2008
  • In this study, three Dimensional CFD simulations were carried out to investigate the effective smoke extraction system in bi-directional road tunnel fires using FLUENT. Characteristics of transverse system with big size extraction port or with uniform extraction port, semi-transverse system and longitudinal system for smoke extraction system were analyzed. Air velocity, port size, and operating method were used with variable. Distributions of smoke spread, CO was analyzed. As a result, the transverse ventilation system with big size port was found to be more effective than the uniform ports for bi-directional road tunnel.

Characteristic Behavior of High-Strength Concrete Columns under Simulated Seismic Loading

  • Hwang, Sun-Kyoung
    • International Journal of Concrete Structures and Materials
    • /
    • v.18 no.2E
    • /
    • pp.79-87
    • /
    • 2006
  • The main objective of this research is to examine the behavior of high-strength concrete(HSC) columns. Eight test columns in one-third scale were tested under the conditions of cyclic lateral force and a constant axial load equal to 30% of the column axial load capacity. The $200{\times}200mm$ square columns were reinforced with eight DB bars constituting a longitudinal steel ratio of 2.54% of the column cross-sectional area. The main experimental parameters were volumetric ratio of transverse reinforcement(${\rho}_s$=1.58, 2.25 percent), tie configuration(Type H, Type C, Type D) and tie yield strength($f_{yh}$=548.8 and 779.1 MPa). It was found that the hysteretic behaviour and ultimate deformability of HSC columns were influenced by the amount and details of transverse reinforcement in the potential plastic hinge regions. Columns of transverse reinforcement in the amount 42 percent higher than that required by seismic provisions of ACI 318-02 showed ductile behavior. At 30% of the axial load capacity, it is recommended that the yield strength of transverse reinforcement be held equal to or below 548.8 MPa. Correlations between the calculated damage index and the damage progress are proposed.

A theoretical calculation of coupled free, transverse vibration of the multi-supported shaft system by the finite element method (유한요소법에 의한 다점지지축계의 연성자유횡진동 계산에 관한 연구)

  • 유광택;전효중
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.10 no.4
    • /
    • pp.41-49
    • /
    • 1986
  • With the trend towards high propulsive level, increasing ship's dimensions and heavier shaft systems supported by the hull structure of relatively stiffness in modern ships, transverse vibrations of propulsion shaft system have become one of the problems that should be predicted in the early design stage. Regarding transverse vibrations, coupling terms such as oilfilm, gyroscope and hydrodynamic effect of the propeller exist between the vertical and horizontal vibration, furthermore for the shaft system with strut and bossing its physical properties incorporated with hull structure must be considered. In order to predict the transverse vibratory condition of the propulsion shaft and take some appropriate countermeasures, it is necessary to make a fairly strict estimation of the vibratory behaviours of it. In this paper, theoretical approach using the finite element method is investigated to calculate natural frequencies and vibration modes for coupled free transverse vibrations of shaft system in two planes. Based on the method investigated a digital computer program is developed and is applied to calculate the above-mentioned vibrations of an experimental model shaft system. The results of the calculation are compared with those of the experimental measurements and they show an acceptable agreement.

  • PDF

Transverse Vibration Control of an Axially Moving String by Velocity Boundary Control (속도경계제어를 이용한 축방향 주행 현의 횡진동 제어)

  • Ryu, Du-Hyeon;Park, Yeong-Pil
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.25 no.1
    • /
    • pp.135-144
    • /
    • 2001
  • In this study, the time varying boundary control using the right boundary transverse motion is suggested to stabilize the transverse vibration of an axially moving string on the basis of the energy flux between the moving string and the boundaries. The effectiveness of the active velocity boundary control is showed through the FDM simulation results. Sliding mode control is adopted in order to achieve velocity tracking control of the time varying right boundary to dissipate vibration energy of the string effectively. Optical sensor system for measuring the transverse vibration of an axially moving string is developed, and the angle of the incident wave to the right boundary, which is the input of the velocity boundary controller, is obtained. Experimental research is carried out to examine the validity and the performance of the transverse vibration control using the suggested velocity right boundary control scheme.

Clinical Study on a Case of Transverse Myelitis (비증(痺證)으로 변증한 횡단성 척수염 환자에 대한 증례 보고)

  • Kim, Jeong-Eun;Kim, Su-Min;Yoon, Hyun-Min;Ahn, Chang-Beohm;Jang, Kyung-Jun;Kim, Cheol-Hong;Kim, Jae-Hong;Kim, Won-Il
    • Journal of Pharmacopuncture
    • /
    • v.11 no.2
    • /
    • pp.141-149
    • /
    • 2008
  • Objectives This report intended to estimate effect taken by using Oriental medical method on the patient with Tranverse Myelitis. Methods From 28th April, 2006 to 19th June, 2006. The patient dignosed as a Transverse Myelitis receive acupuncture, moxibustion, cupping and physical therapy and herbal medication by estimating arthralgia syndrome(痺證). Results The patient's incipient symptoms-both lower limb paresthesia and weakness, voluntary urination and defecation-all were improved. Conclusions This study demonstrates that oriental medical treatment has respectable effect in improving as though we didn't exclude effect of western medical therapy on the patient with transverse myelitis. More research of transverse myelitis is needed.

Effects of Transverse Reinforcement on Strength and Ductility of High-Strength Concrete Columns

  • Hwang, Sun Kyoung;Lim, Byung Hoon;Kim, Chang Gyo;Yun, Hyun Do;Park, Wan Shin
    • Architectural research
    • /
    • v.7 no.1
    • /
    • pp.39-48
    • /
    • 2005
  • Main objective of this research is to evaluate performance of high-strength concrete (HSC) columns for ductility and strength. Eight one-third scale columns with compressive strength of 69 MPa were subjected to a constant axial load corresponding to 30 % of the column axial load capacity and a cyclic horizontal load-inducing reversed bending moment. The variables studied in this research are the volumetric ratio of transverse reinforcement (${\rho}_s=1.58$, 2.25 %), tie configuration (Type H, Type C and Type D) and tie yield strength ($f_{yh}=549$ and 779 MPa). Test results show that the flexural strength of every column exceeds the calculated flexural capacity based on the equivalent concrete stress block used in the current design code. Columns with 42 % higher amounts of transverse reinforcement than that required by seismic provisions of ACI 318-02 showed ductile behaviour, showing a displacement ductility factor (${\mu}_{{\Delta}u}$) of 3.69 to 4.85, and a curvature ductility factor (${\mu}_{{\varphi}u}$) of over 10.0. With an axial load of 30 % of the axial load capacity, it is recommended that the yield strength of transverse reinforcement be held equal to or below 549 MPa.