• Journal of Korean Society of Steel Construction
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• v.25 no.4
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• pp.409-419
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• 2013

A T-stub connection with high-strength bolts under tensile force is affected by prying action force and the contact force, among others, between members. If a design equation that does not consider such prying action force and contact force between members is not proposed, the T-stub under tensile force is liable to be fractured under the strength lower than the estimated design strength. To prevent it, many studies have proposed contact force estimation equations between members as well as the prying action force of the T-stub connection with high-strength bolts. However, no design equations based on such research have been proposed in South Korea. Therefore, this study aims to propose an estimation model for more accurate prying action force and contact force, and improve on previously proposed estimation models by implementing the three-dimensional, nonlinear finite element analysis. Throughout the results of three-dimensional, nonlinear finite element analysis, the prediction model proposed in this research for the prying action force and contact force of a T-stub provided much more accurate estimation than that of a existing prediction model previously suggested.

• Journal of Korean Society of Steel Construction
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• v.15 no.5 s.66
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• pp.541-549
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• 2003

Split-tee connection with High Strength Bolts is normally used in low and middle rise buildings in Europe because the structural efficiency and installation work of connections are excellent. However, the domestic situation is different from that in Europe. The analysis and the design for the T-split connection are complicated, because the structural behavior often T-split connection with High Strength Bolt is governed by so many parameters, i.e., prying action, bolt's tension, shear failure and plastic failure of flange plates. Many researches regarding the structural behavior of the split-tee connection have been undertaken in other parts of the world, such as the, Americas, Japan and Europe, but in the domestic context, this is a pioneering study. Therefore, the purpose of this paper is to supply basic data for the design of T-split connection, and to verify the structural characteristics that define reactions to prying action, based on an experimental study.

• Journal of Korean Society of Steel Construction
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• v.28 no.6
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• pp.459-465
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• 2016

In this paper, it was performed the fatigue test to examine the effect of cyclic loading for the simple T-joint. Axial force of bolt by clamping and the change of the force by applied load were measured in the joint. And the bolt force, the failure mode and the fatigue strength under cyclic loading were investigated. The parameters of the tension joint were set to be the flange thickness and the diameter of bolt to a different stiffness of the joint in response to the combination. From the fatigue test, failure mode of tensile joints under cyclic loading could be evaluated using a static ultimate load of the specific failure mode in EC3. The fatigue strength of the tension joints was considerably higher than the fatigue strength of the EC3(36) that does not consider a lever action. However, the additional axial force by lever action occurs to an increase in the axial force of the bolt it requires a careful evaluation of the fatigue strength.

• Journal of Korean Society of Steel Construction
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• v.27 no.2
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• pp.251-260
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• 2015

The end plate connection is applied to beam-column moment connections in various forms. Such end plate connection displays changes in the behavioral characteristics, strength and stiffness, and energy dissipation capacity based on the thickness and length of the end plate, the number and diameter of the high strength bolt, the gauge distance of the high strength bolt, prying action force of the high strength bolt, and dimensions and length of the welds. Accordingly, this study has apprehended the axial tensile stiffness and prying action force of the high strength bolt connected on the tensile side based on the difference in thickness of the end plate, and was conducted to propose an analysis model for the prediction of such variables that affect the operating properties of the end plate. To achieve this, this study has conducted a three-dimensional non-linear finite-element analysis of the unstiffened expanding end plate connection by selecting only the thickness of the end plate as the variable.

• Journal of the korean veterinary medical association
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• v.37 no.6
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• pp.566-572
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• 2001

체세포 수는 유우유선염증의 측정에 일반적으로 수용되었다. 염증에 대단히 중요한 유방염은 미생물의 존재 또는 유선에 감염된 것이 원인이 된다. 세계의 현대 낙농생산국 들은 SCC는 사람소비가 확대되는 우유 질과 안전성 측정에 유용하다라는 것에 동의한다. 그리고 거의 모든 나라들은 상한 이상을 이룩하였고, 우유는 가공공장에 운반하지 않거나 상한 이상은 현금으로 벌을 취한다. SCC는 우유와 유제품의 국제무역에서 지레 대(leverage)의 힘으로 또한 작용한다. 현재 SCC에 관련된 국제표준은 없다. 그러나 Codex표준과 같은 국제표준은 소비자를 도와 줄 것이다. 그리고 이들에 대한 것을 우유와 유제품국제무역에 포함 시키는 것이다. 많은 것을 낙농목장 내 유방염관리와 낮은 SCC우유생산에서 배웠다. 그리고 우리 지식의 현재상태는 400,000 초과 세계표준은 적절할 수가 없다는 것을 제시하였다. 낙농생산국들은 우유에 허용될 수 있는 염증산물의 수용량에 관하여 동의 되는 것이 필요하다. 염증산물은 현실적으로 SCC에 의한 것이 가장 좋은 측정이 된다 SCC에 대한 국제표준화 이익은 소비자와 낙농산업 양자에게 줄 수 있을 것이다.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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• pp.155-162
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• 2019

Hybrid precast concrete panel is a wall element that is able to quickly construct the core wall structure for moderate-rise modular buildings. Hybrid precast concrete panel has unique characteristics which is a pair of C-shaped steel beams combined at the top and bottom of a concrete wall, In this study, an improved anchorage detail for vertical rebar is proposed to ensure the lateral force resistance performance of hybrid precast concrete panel emulating monolithic concrete wall. Also, the structural performance of horizontal connection is investigated experimentally with the bolt spacing parameter. And the behavior of hybrid precast concrete panel with the improved detail is compared with the monolithic concrete wall tested in a previous study. Finally, the required thickness of C-shaped steel beam to eliminate or minimize the deformation in horizontal connection is calculated by prying action equation.

• Journal of Korean Society of Steel Construction
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• v.29 no.2
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• pp.181-192
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• 2017

A beam splice method using inclined end-plates and high-strength tension bolts was developed. The end-plates welded to a bracket and a spliced beam are connected each other by using the tension bolts. In the present study, six exterior beam-to-column moment connections were tested under cyclic loading. Test parameters were the end-plate details and bolt arrangements. All specimens were designed so that moment resistances of the end-plates and bolts were greater than the required moment at the beam splice, in accordance with the design methods of AISC Design Guide 4. Test results showed that in the beam splices with the extended end-plates, the beam moment successfully transferred to the bracket, without any defeats such as excessive prying action of the end plates and brittle failure at the end plate-to-beam flange weld joints. However, the deformation capacities of the overall beam-to-column connections were limited due to the brittle failure of the beam-to-column flange weld joints. From the test results, recommendations for seismic design and detailing of the beam-to-column moment connection with inclined end-plate beam splice were given.

• Journal of Life Science
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• v.14 no.3
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• pp.484-489
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• 2004

Artificial joint replacement is one of the major surgical advances of the 21th century. The primary purpose of a TKA (Total Knee Arthroplasty) is to restore normal knee Auction. Therefore, ideally, a TKA should: (a) maintain the natural leverage of the knee joint muscles to ensure generating adequate knee muscle moments to accomplish daily tasks such as rising from a chair or climbing stairs;(b) allow the same range of motion as an complete knee; and (c) provide adequate knee joint stability. Four individuals (2 peoples after surgery one year and 2 peoples after surgery three years) participated in this study. All they were prescreened for health and functional status by the same surgeon who performed the operations. Two days of accommodation practice occurred prior to the actual strength testing. The isometric strength (KIN-COM III) of the quadriceps and hamstring were measured at 60$^\circ$ and 30$^\circ$ of knee flexion, respectively. During isokinetic concentric testing, the range of motion was between 10$^\circ$ to 80$^\circ$ of knee flexion (stand-to-sit) and extension (sit-to-stand). for a given test, the trial exhibiting maximum torque was analyzed. A 16-channel MYOPACTM EMG system (Run Technologies, Inc.) was used to collect the differential input surface electromyographic (EMG) signals of the vastus medialis (VM), vastus lateralis(VL), rectus femoris (RF) during sit-to-stand and stand-to-sit tests. Disposable electrodes (Blue SensorTM, Medicotest, Inc.) were used to collect the EMG signals. The results were as follows; 1. Less maximum concentric (16% and 21% less for 1 yew man and 3 years mm, respectively) and isometric (12% and 29%, respectively) quadriceps torque for both participants. 2.14% less maximum hamstrings concentric torque for 1 year man but 16% greater torque for 3 years mm. However, 1 year man had similar hamstring isometric peak torque for both knees. 3. Less quadriceps co-contraction by 1 year man except for the VM at 10$^\circ$-20$^\circ$ and 30$^\circ$-50$^\circ$ range of knee flexion.