• Journal of Korean Society of Steel Construction
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• v.24 no.1
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• pp.109-117
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• 2012

This study seeks to devise a design application for a beam structure with partially restrained composite connection to a CFT column. A cost-efficient and stable component is applied by adjusting the stiffness ratio of the column connection through partially restrained composite connection. Based on a review of the structure's stability, it was confirmed that in the case of a low-rise building as a moment frame, resistance without bracing is feasible because stiffness increased by virtue of the partial restrained composite connection by composite action. In the case of a high-rise building, lateral resistance load of moment frame was approximately 10% when proper partial restrained rate was at around 60%. With considerations related to economic efficiency, the partial restriction effect of the beam component was significantly activated by the uniform load, but that of the beam activated by concentrated load was not significantly indicative. The analysis indicated that 60% partial restrained girder at the connection was the most economical in the case of uniform load. It also showed that end moments can be reduced by approximately 25%.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.53-61
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• 2017

In this study, specimens were produced with a column member and a wooden gusset only by inserting an wooden gusset which is a substitute for steel plate into the center of a slit-processed column member. The moment resistance performance of the specimens was compared with that of control specimens that used a steel plate. The measured maximum moments of the specimens produced with GFRP-reinforced wooden laminated gussets and pins were lower by 24% on average compared to the steel plate-inserted specimens, but they showed good toughness. The fracture shape suggests that it was fractured along the annual rings between the pin and the end of the column member. The rigid specimen that integrated a laminated wood and a wooden laminated gusset with adhesive showed 2.8 times greater initial rigidity and 40% greater maximum moment on average compared to the control specimen. The rigid specimens mainly fractured on a glulam around glue line.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.3
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• pp.21-28
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• 2008

To evaluate the seismic performance of multi-degree of freedom(MDF) systems, repeated nonlinear response history analyses are often conducted, which require extensive computational efforts. To reduce the amount of computation required, equivalent single degree of freedom(SDF) systems representing complex multi-degree of freedom(MDF) systems have been developed. For the equivalent SDF systems, bilinear models and trilinear models have been most commonly used. In these models, the P-$\Delta$ effect due to gravity loads during earthquakes can be accounted for by assigning negative stiffness after elastic range. This study evaluates the adequacy of equivalent SDF systems having these hysteretic models to predict the actual response of steel moment resisting frames(SMRF). For this purpose, this study conducts cyclic pushover analysis, nonlinear time history analysis and incremental dynamic analysis(IDA) for SAC-Los Angeles 9-story buildings using nonlinear MDF models(exact) and equivalent SDF models(approximate). In addition, this study considers the strength limited model.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.484-492
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• 2023

The structural behaviour of concrete beam was examined by the three points bending test after the completion of the electrochemical chloride extraction (ECE), rather than bond strength mostly measured in previous studies. It was found that the flexural rigidity of concrete was lowered by the ECE, but the strength was enhanced in terms of the maximum load.The flexural rigidity, in the linear elastic range, was reduced by the loss of effective cross-section area. In fact, the inertia moment was substantially subjected to 70 % loss of the cross-section by the tensile strain at the condition of the failure. However, a lower rate of the inertia moment reduction was achieved by the ECE, implying the higher resistance to the cracking, but the higher risk of deformation.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.5
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• pp.1-12
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• 2023

This study evaluated the overturning stability of portable tripod ladders used for high-altitude work such as tree management and pruning work in landscaping construction and management. Portable tripod ladders, which are included in general mobile or portable ladders frequently used in industrial sites, are supported in a triangular support structure, not a 4-point support like common A-type Ladders. In addition, since the working height is more than twice that of a mobile or portable ladder, the possibility of an overturning accident that threatens the safety of workers with a fall accident is high. Therefore, based on the overturning stability test specified in ANSI-ASC A14.7 and EN 131-Part 7, which are related standards for about 130 types of portable tripod ladders sold and used in Korea. An equation to calculate each moment according to working height was derived. Then, each calculated moment was compared to evaluate the safety factor for overturning and stability. As a result of the overturning stability evaluation according to each standard, when the provisions of EN 131-Part 7 were applied, portable tripod ladders with 8 steps in the rear direction and 6 steps or more in the side direction were evaluated as unstable against overturning, but according to ANSI-ASC A14.7 regulations. It was evaluated that the stability against overturning was secured in all directions and number of steps.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.5
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• pp.277-286
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• 2022

The elastic and inelastic responses obtained from the experimental and analytical results of two RC building structures under the service level earthquake (SLE) and maximum considered earthquake (MCE) in Korea were used to weinvestigate the characteristics of the mechanisms resisting shear and torsional behavior in torsionally unbalanced structures. Equations representing the interactive effect of translational drift and torsional deformation on the shear force and torsional moment were proposed. Because there is no correlation in the behavior between elastic and inelastic forces and strains, the incremental shear forces and incremental torsional moments were analyzed in terms of their corresponding incremental drifts and incremental torsional deformations with respect to the yield, unloading, and reloading phases around the maximum edge-frame drift. In the elastic combination of the two dominant modes, the translational drift mainly contributes to the shear force, whereas the torsional deformation contributes significantly to the overall torsional moment. However, this phenomenon is mostly altered in the inelastic response such that the incremental translational drift contributes to both the incremental shear forces and incremental torsional moments. In addition, the given equation is used to account for all phenomena, such as the reduction in torsional eccentricity, degradation of torsional stiffness, and apparent energy generation in an inelastic response.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.2
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• pp.1-12
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• 2017

In this study, It was purpose to provide preliminary data for extension of the applicability of deep corrugated steel plate composite members by steel grade and shear reinforcement method. From the result of flexural test on deep corrugated plates composite members using GR40 and SS590, positive moment capacity was increased about 28% by SS590 steel. But to change steel grade was proved to have insignificant effects for increasement of negative moment capacity. In the moment test result of same overlapping length, Increasement rate of positive and negative moment capacity was not significantly improved by increasing the number of bolt. It was estimated to be due to the characteristics of bolt connection such as distance between centers of bolts, edge distance of bolt. In the test result on the spacing of shear reinforcement, positive moment capacity was increased and deformation of negative moment was reduced as the distance decrease. In the test result on the shape of shear reinforcement, positive and negative moment resistance was increased about 2% ~ 7% by U shaped shear reinforcement. In conclusion It was estimated that moment capacity of deep corrugated steel plate composite members are depend on steel grade of deep corrugated steel plate, spacing of shear reinforcement and reinforcing bar.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.6
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• pp.238-245
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• 2010

Progressive collapse is defined as a collapse caused by sectional destruction of a structural member which links to other surrounding structures. Currently the design guidelines for the prevention of progressive collapse is not available in Korea. So, structural engineers have a difficulty in evaluating progressive collapse. In this study, the static and dynamic analysis to evaluate the methods and procedures are conducted using commercial analysis program for RC moment resisting frames. According to the study, DCR value of RC moment resisting frame system based on code in Korea is over 2 and it shows that it can't provide alternate load paths due to the progressive collapse. And additional reinforcement should be considered for the progressive collapse resistance. As a result of vertical deflection and DCR value of linear static analysis and linear dynamic analysis, the results of dynamic analysis were underestimated more than the result of static analysis. Thus, the dynamic coefficient value of 2 provides conservative estimation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.84-91
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• 2022

This study investigated the behavior of out-of-plane skewed moment connections that were designed as IMFs, as per the Korean standards. A total of 14 finite element models were constructed with the consideration of two types (single- and double-sided connections) and four levels of skew angle (0°, 10°, 20°, and 30°). The results indicated that the skewed connections considered in this study met the acceptance criteria for IMFs given by the codes. However, the load-carrying capacities of skewed connections were decreased as the skew angle increased. For the connection with a skew angle of 30°, the peak load was noted to be 13% less and the energy dissipation capacity could be 26% less than that of non-skewed connection. In addition, because of the skewed nature, the stress distribution in the skewed beam flange near the connection was asymmetric and the stresses were concentrated on the beam inner flange. Column twisting induced by the skewed configuration was very small and negligible in the beam and column combination considered in this study.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.150-153
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• 2010

본 논문에서는 비내진 설계된 철근콘크리트 골조로 이루어진 저층의 노후공동주택의 내진성능을 향상시키기 위한 구조물의 보강방법에 대해 연구하였다. 이를 위하여 비선형 정적 해석과 시간 이력 해석을 수행하여 추가되는 철골 모멘트골조와 가새의 내진보강 효과를 검증하였다. 해석결과에 따르면 $H150{\times}150{\times}6{\times}8$로 구성된 철골 모멘트골조는 탄성구간에서는 하중의 약 1%, 구조물이 항복한 이후, 최대 3.5%까지 하중을 부담하여 자체적으로 지진하중에 대한 저항 성능은 크지 않았다. 그러나 철골 모멘트골조와 가새를 동시에 사용함으로써 접합부의 조기 파괴를 방지하고 구조물의 내진성능을 큰 폭으로 증진시킬 수 있는 것으로 나타났다.