• Computers and Concrete
• /
• v.23 no.6
• /
• pp.377-398
• /
• 2019

Behavior of RC beam-column joint is very complex as the composite material behaves differently in elastic and inelastic range. The approaches generally used for predicting joint shear strength are either based on theoretical, strut-and-tie or empirical methods. These approaches are incapable of predicting the accurate response of the joint for entire range of loading. In the present study a new generalized RC beam-column joint shear strength model based on hybrid approach i.e. combined strut-and-tie and empirical approach has been proposed. The contribution of governing parameters affecting the joint shear strength under compression has been derived from compressive strut approach whereas; the governing parameters active under tension has been extracted from empirical approach. The proposed model is applicable for various conditions such as, joints reinforced either with or without shear reinforcement, joints with wide beam or wide column, joints with transverse beams and slab, joints reinforced with X-bars, different anchorage of beam bar, and column subjected to various axial loading conditions. The joint shear strength prediction of the proposed model has been compared with 435 experimental results and with eleven popular models from literature. In comparison to other eleven models the prediction of the proposed model is found closest to the experimental results. Moreover, from statistical analysis of the results, the proposed model has the least coefficient of variation. The proposed model is simple in application and can be effectively used by designers.

• Journal of the Korea Concrete Institute
• /
• v.22 no.3
• /
• pp.357-366
• /
• 2010

This paper presents experimental results about shear wall with various lateral reinforcement details in boundary elements. The research objective is to study the structural behavior of shear wall with boundary column confined by rectangular spiral hoops and headed cross ties developed to improve workability in the fabrication of boundary columns. These two details can be fabricated in a factory and put together on-site after being delivered so that the construction work may be reduced. Main parameters in the experimental study were the types of hoop and cross tie: rectangular spiral hoop and headed cross tie vs. standard hoop and cross tie with hook. Four half scaled shear wall specimens with babel shape were made and tested by applying horizontal cyclic load under constant axial force, 10% of nominal compressive strength of concrete. Based on the test result, it was shown that the shear wall with rectangular spiral hoop and headed cross tie in boundary columns has structural capacity compatible with conventional shear wall. The specimen SW-Hh which has bigger hoop bar and higher volumetric ratio of transverse reinforcements than other showed improved energy dissipating characteristic but it presented a rapid reduction of strength after peak point. The results indicates that, it is necessary to consider volumetric ratio of transverse reinforcements as well as hoop space in designing of shear wall with boundary columns for improved strength and ductility.

• Bulletin of the Korean Space Science Society
• /
• 2003.10a
• /
• pp.109-109
• /
• 2003

원자외선분광기(FIMS), 우주물리탑재체(SPP)를 탑재한 과학기술위성 1호는 무게 약 106kg으로 고도 690km의 원형궤도에 러시아의 COSMOS-3M에 의해 플레세츠크(Plesetsk)에서 발사 되었다. 과학기술위성 1호는 적층타입(Stack Type)으로 구조체가 설계되었으며, 하나의 모듈을 하나의 구조물로 만들어 여러 개의 구조물을 쌓아 타이바(Tie Bar)를 사용하여 체결하는 방식을 채택하고 있다. 이것은 모듈을 구조체로 사용함으로써 무게를 줄일 수 있으며, 강성이 높고, 하니스 처리가 용이한 장점이 있다. 구조체는 발사환경과 우주환경을 견디도록 설계되어야 하며, 그 과정을 지상에서 시험으로 검증을 하게 된다. 본 논문은 과학기술위성 1호의 구조물 개발과정과 제작과정을 설명하고, 제작된 구조물의 시험과정과 결과를 살펴보았다.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10a
• /
• pp.711-717
• /
• 2000

This paper presents an experimental study on evaluation of structural performance on corroded reinforced concrete columns under only axial load, combined axial load and lateral load. This test was carried on the twenty-six reinforced concrete columns with $150\times150\times800$mm size subjected to combined axial load and lateral load. Effects of key variables such as the corrosion level, the number of hoop, the corrosion of hoop are studied in this program. The results of this study show that the capacity of column axial force was decreased as corrosion level was increased, especially, rapid development was shown after 10% corrosion level and the maximum moment capacity of column was shown at corrosion level 1.2%, while rapid decrease was shown after 4.3% corrosion level. Also we found that influence of corrosion was decreased to number of tie bar was increased.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.03b
• /
• pp.35-38
• /
• 1999

Tube bending is an important factor of the hydroforming processes. The tube must be bent to the approximate centerline of the finished part prior to hydroforming to enable the tube to be placed in the die cavity. This paper presents the simulation results in prebending process by a rotary bending machne and a bend die that is used to form an automotive part a tie bar, Prebending simulation is carried out to obtain the shape change of cross section and thinning in bending process. To avoid occurring wrinkle in compressive zone during bending process a wiper die included,. A parametric study is carried out to obtain the effect of the forming parameters such as a bend radius and tube thickness

• Journal of the Korea Concrete Institute
• /
• v.12 no.4
• /
• pp.3-14
• /
• 2000

Structural performance of the walls subjected to lateral load reversals depends on various parameters such as loading history, sectional shape, reinforcement, lateral confinement, aspect ratio, axial compression, etc. Thus, the performance of the shearwall for wall-type apartment should be evaluated properly considering above parameters. This study investigates the effect of sectional shape on the structural performance of the wall. Sectional shape of the specimen is rectangular, barbell and T. Based on this experimental results, all specimens behaved as ductile fashion and failed by concrete crushing of the compression zone. Deformation index of those specimens evaluated better than 3 of ductility ratio, and 1.5% of deformability specified by seismic provision. Moreover, the performance of the rectangular shaped specimen, whose compression zone was confined with U-bar and cross tie, was as good as the barbell shaped specimen. Therefore, if we considered construction practice such as workmanship and detailing, shearwall with rectangular section may be more economical lateral load resisting system.

• The Safety technology
• /
• no.171
• /
• pp.18-19
• /
• 2012

경기도 안산시 반월공단에 소재한 (주)승진기계는 국내 최초이자 유일의 대형 롤러(Roller)류 전문 제작업체로, 1985년 설립됐다. 이곳은 27년의 역사를 자랑하는 만큼 상당한 생산 및 기술력을 지니고 있다. 프레스용, 사출기용 Tie-bar, 제지용 Calener roll 등 산업현자에서 쓰이는 각종 대형 롤러 대부분을 제작 생산할 수 있는 시스템을 갖추고 있는 것이다. 이런 방대한 능력을 반영하듯 국내 굴지의 기업인 포스코, 현대제철, 두산중공업, 동부제철 등이 이곳과 협력관계를 맺고 있다. 이곳 임직원들은 이같은 우수한 기술력과 생산력의 비결로 '안전을 향한 도전의식'을 꼽는다. 작업현장의 안전이 기술 및 생산력 제고의 원전이라는 신념 아래, 끊임없는 노력을 기울인 결과 지금의 성과를 이룩했다는 것이 그 설명. 안전으로 국내 최고의 대형 롤러 제작업체로 우뚝 서는데 크게 기여한 (주)승진기계의 나란수 공장장을 만나봤다.

• Journal of Powder Materials
• /
• v.6 no.1
• /
• pp.18-35
• /
• 1999

Phase equilibria in the system Si3N4-TiC-TiCxN1-x-C-N were determined by thermodynamic calculations (CALPHAD-method). The reaction peaction paths for Si3N4-TiC and SiC-TiC composites in the Ti-Si-C-n system were simulated at I bar N2-pressure and varying terpreatures. At a temperature of 1923 K two tie-triangles (TiC0.34N0.66+SiC+C and TiC0.13N0.87+SiC+Si3N4) and two 2-phase fieds (TiCxN1-x+SiC; 0.13

• Journal of the Korea Institute of Building Construction
• /
• v.18 no.2
• /
• pp.99-107
• /
• 2018

The objective of the present study is to propose a reliable shape of supplementary V-ties in the section jacketing approach for seismic strengthening of reinforced concrete columns. A total of 24 pull-out specimens were prepared. The test parameters selected with regard to bond strength of V-ties were the shape of V-ties, embedment length of V-tie legs, and compressive strength of concrete. The measured bond strength of V-ties with different shapes were compared with that of the conventional V-ties and predictions using CEB-FIP equation. Ultimately, V-ties with pressed end-details at their legs could be recommended for the supplementary lateral reinforcement of strengthening columns with jacketing thickness less than the embedment length [= max (75mm, $6d_b$)] of conventional V-ties, where $d_b$ is the diameter of the reinforcing bar used for V-ties.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.12 s.189
• /
• pp.88-94
• /
• 2006

In this study, the dynamic impact analysis for the passenger air-bag(PAB) module has been carried out by using FEM to predict the dynamic characteristics of vehicle ride safety against head impact. The impact performance of vehicle air-bag is directly related to the design parameters of passenger air-bag module assembly, such as the tie bar bracket's width and thickness, respectively, However, the product's design of PAB module parameters are estimated through experimental trial and error according to the designer's experience, generally. Therefore, the dynamic analysis of head impact test of the passenger air-bag module assembly of automobile is needed to construct the analytical methodology At first, the FE models, which are consist of instrument panel, PAB Module, and head part, are combined to the whole module system. Then, impact analysis is carried out by the explicit solution procedure with assembled FE model. And the dynamic characteristics of the head impact are observed to prove the effectiveness of the proposed method by comparing with the experimental results. The better optimized impact performance characteristics is proposed by changing the tie bracket's width md thickness of module. The proposed approach of impact analysis will provides an efficient vehicle to improve the design quality and reduce the design period and cost. The results reported herein will provide a better understanding of the vehicle dynamic characteristics against head impact.