• Journal of the Earthquake Engineering Society of Korea
• /
• v.6 no.3
• /
• pp.63-71
• /
• 2002

The seismic design regulations have not been applied to the low-rised buildings which are less than 6 stories in Korea. For these buildings which are designed only for gravity loads, theoretical formulas which can estimate the seismic strength of building are derived. The column hinge sway and beam hinge sway mechanism are assumed for the formulars. For the comparisons with the formulas, the results of push-over analyses of 3 and 4 storied buildings are used. It can be shown that the estimating formulas correspond well with the push-over analyses. And the seismic strength of building has a little relations with the number of bay and becomes larger as the building becomes lower. Also, as the ratio and strength of reinforcing steel increase, the seismic strength of building is increased.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.15 no.3
• /
• pp.186-194
• /
• 2011

The reinforced concrete beam-column connections are in lack of constructability and are likely to show anchorage failure because of the complex details of joint regions. Under seismic loads, a destruction of the column or the beam-column joint leads to collapse of the whole structures. For this reason, the safety of structures has to be guaranteed by following procedures which are based on the strong column-weak beam design concept: 1) failure of beam by generating plastic hinge in the beam maintained a certain distance from the surface of column, 2) failure of column or beam-column joint. In this study, headed bars were used as longitudinal reinforcements of beam and joint reinforcements in order to improve the strength and constructability of joint and to relocate plastic hinge. The finite element analyses (FEAs) were performed to the reinforced concrete beam-column joints utilizing headed bar reinforcements. To verify the availability of the analysis models, the FEAs for experimental tests performed by previous researchers were conducted and compared with the experimental results. Additional variables are also considered to confirm the excellence of headed bars. Analysis results indicate that the constructability of beam-column connections can be improved by using headed bars for the full anchorage of longitudinal reinforcements of beam under similar structural performance. In addition, the plastic hinge was relocated to the intended place by using headed bars as joint reinforcements. Under cyclic displacement loading, the energy dissipation capacity and ultimate stress were increased and the decrease in stiffness was minimized.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2004.07a
• /
• pp.88-88
• /
• 2004

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2011.04a
• /
• pp.10-13
• /
• 2011

내진설계의 기본 개념은 보를 기둥보다 약하게 설계하여 보에 소성힌지를 발생시켜 구조물 전체의 큰 변형을 방지하는 것이다. ACI 352R-02에서는 지역의 지진특성에 따라서 접합부의 상세 설계법을 구분하여 적용한다. 하지만 보와 접합부의 내력 차이가 상대적으로 작게 설계된 구조물의 경우 탄성 범위를 유지해야 하는 경우의 접합부에도 파괴가 발생할 가능성이 있다. 횡하중이 작용할 때 접합부 내부는 전단력의 지배를 받게 되고, 전단내력과 부착내력에 따라서 파괴모드가 결정된다. 본 논문에서는 양방향 반복하중이 작용하는 10개의 보-기둥 접합부를 통해서 접합부와 인접보의 전단내력 차이에 따라서 발생하는 파괴모드를 관찰하고 접합부 내의 전단내력 및 부착내력의 감소로 인해 발생하는 부재의 연성에 대해서 관찰하였다.

• 대한공업교육학회지
• /
• v.33 no.2
• /
• pp.312-324
• /
• 2008

To improve the newly designed HKS(hinge kit system) in common refrigerators, it was investigated the new robust methodologies. There were the study of failure modes, mechanisms in the marketplace, and the design parameters of HKS with various improvements using accelerated life testing. Based on the claimed marketplace product returns and 1st ALT reproduction, the fracturing and cracking occur in the housing of the HKS. The missing design parameters of the failed HKS in the design phase of the refrigerator was the housing hinge kit structure. The corrective action plans are the modifications of the housing hinge kit structure from the open supporting to all supporting structure. Based on 2nd ALTs, the fracturing and cracking occur in the torsion shaft. The missing design parameter was the roundness of torsion shaft. After a sequence of ALT testing, the levels of the missing design parameters were setup. The yearly failure rate and B1 life of the redesigned HKS, based on the results of ALT, were over 0.01 percent and 10 years, respectively. The parameter design through the inspection of the failed product, load analysis, and three rounds of ALT, was very effective in the new robust design methodologies of the mechanical system and this method can be applied to other design system.

• Journal of the Korea Concrete Institute
• /
• v.23 no.2
• /
• pp.177-184
• /
• 2011

This paper describes an analytical study on the design approach of PC system with continuous connections at member ends. In multi-ribbed moment resisting slab (MRS) system, double tee members are connected continuously over inverted tee beams with the continuous reinforcements placed within topping concrete. Thus, negative moments are concentrated within the narrow connection area. In order to propose a design method, experimental results of the companion study were examined using detailed nonlinear analysis. Then nonlinear static analysis was used to evaluate the partial continuity effect and the moment redistribution mechanism. Material and cross sectional properties were obtained from experimental results of the companion study. Plastic hinge properties for nonlinear static analysis were modeled with cracking moment, nominal moment, corresponding member deformations, etc. The analysis results showed that a large amount of negative moment of MRS slab can be reduced by applying partial continuity and moment redistribution in MRS joint.

• Journal of Korean Society of Steel Construction
• /
• v.9 no.4 s.33
• /
• pp.557-578
• /
• 1997

The objective of the study in this paper was to develop a beam-column element to model members with purely flexural yielding, as well as members with yielding under combined flexure and axial force during severe earthquake ground motins. The developed element can be considered as an one-component series hinge type model. It has the capability to model plastic axial deformation and changes in axial stiffness, and employs hardening rules to handle monotonic, cyclic or arbitrary loading. In general, when compared to experimental results and fiber model predictions, the element showed significantly better performance than the bilinear hinger model and could properly model the beam-column behavior of bare steel members in moment resisting frames. The developed element can more accurately predict local deformation demands and overall responses of structural systems under earthquake loadings than the bilinear hinge element.

• Journal of Korean Society of Steel Construction
• /
• v.27 no.2
• /
• pp.195-205
• /
• 2015

The rahmen bridge is well known common type of bridge in which all members are connected rigidly. The rahmen bridge is built for several situations because it has many advantages such as no need of bridge bearing system, easy of maintenance, reduction of the cross-sectional area of superstructure, and relatively low construction cost compared with other bridge types. Recently, to lengthen the span of rahmen bridge system, steel-concrete composite beam is used for superstructure of rahmen bridge instead of normal concrete girder with slab. However, member forces are increased because of extension of span length of superstructure and substructure is designed and constructed inefficiently when steel-concrete composite rahmen bridge is designed. In this study, new-type steel-concrete composite bridge is suggested. New-type steel-concrete composite rahmen bridge is adopted hinge connection between abutment and foundation for the reduction of the bending momemt at the foundation. In this study, we present the results of experiment conducted to estimate the load carrying capacity of new-type steel-concrete composite rahmen bridge and the structural characteristics of hinge connection.

• Journal of Korean Association for Spatial Structures
• /
• v.9 no.1
• /
• pp.69-78
• /
• 2009

Recent earthquake, such as the Northridge(1994), the Kobe(1995) and the Izmit(1990) earthquakes, gave serious damage in various buildings and bridges by the vertical seismic component. Most of the seismic designs neglect the vertical seismic component for usual frame structures. The purpose of this study is to evaluate the effects of the vertical seismic component and to compare the axial force of columns and plastic rotation angle of the analytical models in these effects. The vertical seismic component produced a large increment of axial force in columns. And the vertical seismic component caused a significant increase of the damage in the columns. As analysis result, increase of axial force cause the damage of columns and give possibility of story collapse mechanism of the structure system. Therefore, area that near fault ground motion is expected may be consider the effect of vertical component of seismic ground motions.

• Tunnel and Underground Space
• /
• v.8 no.4
• /
• pp.261-274
• /
• 1998

The brief results of laboratory and field tests of yieldable steel arches are represented. The test supports were fabricated with three U-sectional beams which are 25.8 kg/m of Glocken profile. The structural analyses of semi-circular and arch supports were conducted to find out shape factor of U beam to be 1.35 and the location of 2nd plastic hinges. Load capacity of arch supports under crown loading were examined as a function of leg length. Yieldable characheristics of test supports were investigated with various bolting torque of connection part. Determination method of bolting torque were also studied. Finally, test supports were installed in-situ with torque of 21 kg .m, which showed a typical yielding procedure.