• Earthquakes and Structures
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• v.11 no.5
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• pp.905-924
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• 2016

Several two-dimensional analytical beam column joint models with varying complexities have been proposed in quantifying joint flexibility during seismic vulnerability assessment of non-ductile reinforced concrete (RC) frames. Notable models are the single component rotational spring element and the super element joint model that can effectively capture the governing inelastic mechanisms under severe ground motions. Even though both models have been extensively calibrated and verified using quasi-static test of joint sub-assemblages, a comparative study of the inelastic seismic responses under nonlinear time history analysis (NTHA) of RC frames has not been thoroughly evaluated. This study employs three hypothetical case study RC frames subjected to increasing ground motion intensities to study their inherent variations. Results indicate that the super element joint model overestimates the transient drift ratio at the first story and becomes highly un-conservative by under-predicting the drift ratios at the roof level when compared to the single-component model and the conventional rigid joint assumption. In addition, between these story levels, a decline in the drift ratios is observed as the story level increased. However, from this limited study, there is no consistent evidence to suggest that care should be taken in selecting either a single or multi component joint model for seismic risk assessment of buildings when a global demand measure such as maximum inter-storey drift is employed in the seismic assessment framework.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.603-611
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• 2006

The fundamental joint configuration that is often applied in offshore structures is the K-joint. The paper describes a numerical parametric study for K-joint parameters (using the finite element program) and compared with results of the experimental test. The stress effects of various parameters including $\alpha,\;\beta,\;\gamma,\;\tau\;and\;\theta$ were investigated. The paper introduces the stress distributions as per each parameter. From the study, the maximum stress of joint became different according to the variation of joint parameters.

• The Journal of Korean Physical Therapy
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• v.25 no.2
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• pp.117-125
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• 2013

Purpose: The purpose of this study was to investigate changes in movement strategies of lower limb joints depending on the type of heel during sit-to-stand. Methods: Twenty healthy females participated in this study. All subjects performed sit-to-stand three times each with three different types of heels - bare feet, 9 cm high-heeled shoes, and unstable shoes. Trails were conducted in random order. Three-dimensional motion analysis systems were used for collection and analysis of the kinematic data of lower limb movements. Results: Results of this study showed kinematic differences in pelvis, hip joints, knee joints, and ankle joints during sit-to-stand based on the type of heels. At the initial sit-to-stand, hip joint flexion, knee joint flexion, ankle joint flexion, and ankle joint inversion showed significant differences. The maximal angles of hip joint flexion, hip joint adduction, knee joint flexion, ankle joint flexion, and ankle joint inversion were significantly different, while hip joint adduction, pelvic forward tilt, hip joint rotation, knee joint flexion, ankle joint flexion, and ankle joint inversion differed significantly during the terminal of sit-to-stand. Conclusion: Therefore, the type of heel played an important role in selection of lower limb movements during sit-to-stand which were essential parts of daily life movements.

• International journal of steel structures
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• v.18 no.4
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• pp.1373-1383
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• 2018

Experimental study was conducted to investigate the seismic behavior of roof joint. Eight full-scale specimens were tested considering the effects of axial force, joint height, hole shape of base plate and edge distance of concrete on the failure mode and resistance capacity of roof joint. With the increase of axial force, the hysteretic curves were fuller. The mechanical model of roof joint change from bending to shear. With the increase of joint height, the ultimate strength of roof joint decreased. If the hole shape of base plate changed from circle to loose, the slip behavior of roof joint appeared and the ultimate strength of roof joint decreased. The damage of edge concrete may occur if the edge distance of concrete was not big enough.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.1
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• pp.94-99
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• 2004

The global stiffnesses and vibration characteristics of vehicle structures are mainly influenced by local stiffnesses of the joint structures consisted of complicated thin-walled panels. In this paper, the parametric study for the stiffnesses of the center pillar-roof rail joint of vehicle structure is performed through the linear static analysis. The analysis result shows that the reinforcement panel much affects the joint stiffness of out-plane direction (i.e., z-direction). And also, the flange radius and width of the joint structure much affect the Joint stiffness of out-plane direction. The study shows that vehicle joint stiffnesses can be effectively determined in designing vehicle structure through the parametric study.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.9-20
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• 2014

PURPOSES : This study is to compare load transfer efficiency of key joint and dowel joint for airport concrete pavement. METHODS : As AC150/5320-6D of FAA's [Advisory Circular] was changed into AC150/5320-6E, Key joint type of rigid pavement were excluded from Construction Joints. LTE(Load Transfer Efficiency) of dowel joint and key joint were compared by times and seasons through pavement temperature measurement, ocular investigation and HWD measurement. RESULTS : For the joint performance grade of No. 2(The second) runway of airport, 12% of poor rate was observed in key joint and 2% of poor rate in dowel joint. Poor rate of key joint was increased to 17%, if only No. 3~No. 6 slabs, which are mostly loaded from the airplanes, were applied for the study. In apron area, LTE poor rate of key joint was high in winter, and LTE poor rate of dowel joint was at least above 'Fair' grade. In summer, 'Fair' for key joint, 'Acceptable' for dowel joint appeared. CONCLUSIONS : As results, dowel joint was superior than key joint for LTE. Deviations of seasons and times were smaller in dowel joint's result. And LTE in winter was lower than LTE in summer.

• Journal of architectural history
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• v.16 no.6
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• pp.87-100
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• 2007

This study examines on the structural Methods between purlin and beam at Wooden Architecture in Joseon Dynasty($1372{\sim}1910$). Through the investigation, it is verified that the structural methods between purlin and beam is the technique utilizing tenon joint(통장부맞춤), Sungeoteok joint(숭어턱맞춤), dovetailed tenon joint(주먹장맞춤). And the methods of tenon joint is followed by the Sungeoteok joint, which is used in the buildings after middle Joseon dynasty. The method of tenon joint(통장부맞춤) is to connect the beam with the purlin by carving out the head of the beam as '一' shape. And the structural methods between Janghyeo(장혀, timber under purlin) and beam is halved joint(반턱맞춤) and tenon joint (통장부맞춤). The buildings in late Goryeo Dynasty and Joseon Dynasty adopted the method of tenon joint between purlin and beam. The method of Sungeoteok joint is to connect the beam with the purlins by carving out the head of the beams '凸' shape. And the structural methods between Janghyeo and beams is halved joint(반턱맞춤) and tenon joint(통장부맞춤), the method of tenon and step joint(통장부턱맞춤), dovetailed joint between beam and Janghyeo to increase the security of shear force.

• Journal of the Korea Safety Management & Science
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• v.7 no.1
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• pp.179-198
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• 2005

The purpose of this study is to propose a strategic approach to improve firms competitive advantages by selecting main business body and business sector at the same time. In this study the strategy of an efficient business model for joint logistics is suggested by means of searching for a joint program. The methods applied to this study were literature survey, questionnaire and internet information as well as case studies on advanced domestics and foreign logistics enterprises. The research scope of this study has focused on the joint logistics of SMEs being in the DVD(Digital Video Disk) industry sector. The results of this study are shown as follows ; first, in short terms, main business operating body has, second, in long terms, logistics operating enterprise has a direct effect on the joint logistics operation strategy of the DVD(Digital Video Disk) industry in Korea. The conclusion of this study shows that this method as a model of consequence to increase the joint logistics implementation successfully.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1160-1165
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• 2004

The purpose of this study was to calculate three dimensional angular displacements, moments and joint reaction forces of the ankle joint during the waist pulling, and to assess the ankle joint reaction forces according to different perturbation modes and different levels of perturbation magnitude. Ankle joint model was assumed 3-D ball and socket joint which is capable of three rotational movements. We used 6 cameras, force plate and waist pulling system. Two different waist pulling systems were adopted for forward sway with three magnitudes each. From motion data and ground reaction forces, we could calculate 3-D angular displacements, moments and joint reaction forces during the recovery of postural balance control. From the experiment using falling mass perturbation, joint moments were larger than those from the experiment using air cylinder pulling system with milder perturbation. However, JRF were similar nevertheless the difference in joint moment. From this finding, we could conjecture that the human body employs different strategies to protect joints by decreasing joint reaction forces, like using the joint movement of flexion or extension or compensating joint reaction force with surrounding soft tissues. Therefore, biomechanical analysis of human ankle joint presented in this study is considered useful for understanding balance control and ankle injury mechanism.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.1
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• pp.51-56
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• 2007

The K-joint is one of the commonly applied element in offshore structures. Due to its structural configuration, the stress concentration occurs in the joint. Considering the important effect to the structural safety and the design optimization, a design guideline is strongly required. The main variables determining the configuration of K-joint including ${\alpha},\;{\beta},\;{\gamma},\;{\tau}$ and ${\theta}$ are closely investigated to find the individual effect to the Stress to K-joint. The maximum Stress of joint has been differed as per the variation of parameters. The parametric study has been numerically carried out and compare with the experimental data.