• Title/Summary/Keyword: joint core

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Shear behavior of RC interior joints with beams of different depths under cyclic loading

  • Xi, Kailin;Xing, Guohua;Wu, Tao;Liu, Boquan
    • Earthquakes and Structures
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    • v.15 no.2
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    • pp.145-153
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    • 2018
  • Extensive reinforced concrete interior beam-column joints with beams of different depths have been used in large industrial buildings and tall building structures under the demand of craft or function. The seismic behavior of the joint, particularly the relationship between deformation and strength in the core region of these eccentric reinforced concrete beam-column joints, has rarely been investigated. This paper performed a theoretical study on the effects of geometric features on the shear strength of the reinforced concrete interior beam-column joints with beams of different depths, which was critical factor in seismic behavior. A new model was developed to analyze the relationship between the shear strength and deformation based on the Equivalent Strut Mechanism (ESM), which combined the truss model and the diagonal strut model. Additionally, this paper developed a simplified calculation method to estimate the shear strength of these type eccentric joints. The accuracy of the model was verified as the modifying analysis data fitted to the test results, which was a loading test of 6 eccentric joints conducted previously.

A Proposal of New MOE to Assess the Combat Power Synergistic Effect of Warfare Information System (전장 정보체계의 전투력 상승효과 측정을 위한 새로운 MOE 제안)

  • Lee, Yong-Bok;Jung, Whan-Sik;Kim, Yong-Heup;Lee, Jae-Yeong
    • IE interfaces
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    • v.22 no.3
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    • pp.205-213
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    • 2009
  • Warfare information system is a core factor of future combat operation under NCW(Network centric Warfare) environment. In this paper, we proposed a new MOE(Measure of Effectiveness) that can assess the combat power synergistic effect of warfare information system in the theater-level joint fire operation. This new MOE uses the rule of Newton's second law($F=(m{\Delta}{\upsilon})/{\Delta}t{\Rightarrow}(M{\upsilon}I)/T$). Four factors considered in combat power evaluation are network power(M), movement velocity(v), information superiority(I), command and control time(T). We applied this new MOE to the JFOS-K(Joint Fire Operating System-Korea) to assess its combat power effect and compared with other's effects obtained from different MOE.

Effect of bond and bidirectional bolting on hysteretic performance of through bolt CFST connections

  • Ajith, M.S.;Beena, K.P.;Sheela, S.
    • Earthquakes and Structures
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    • v.19 no.5
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    • pp.315-329
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    • 2020
  • Through bolt connections in Concrete Filled Steel Tubes (CFSTs) has been proved to be good in terms of seismic performance and constructability. Stiffened extended end plate connection with full through type bolt helps to avoid field weld altogether, and hence to improve the quality of joints. An experimental study was conducted on the hysteretic performance of square interior beam-column connections using flat extended end plates with through bolt. The study focuses on the effect of the bond between the tie rod and the core concrete on the cyclic performance of the joint. The study also quantifies how much the interior joint is getting strengthened due to the confinement effect induced by bi-directional bolting, which is widely used in 3D moment resisting frames. For a better understanding of the mechanism and for the prediction of shear capacity of the panel zone, a mathematical model was generated. The various parameters included in the model are the influence of axial load, amount of prestress induced by bolt tightening, anchorage, and the concrete strut action. The study investigates the strength, stiffness, ductility, and energy dissipation characteristics. The results indicate that the seismic resistance is at par with American Institute of Steel Construction (AISC) seismic recommendations. The bidirectional bolting and bond effect have got remarkable influence on the performance of joints.

Effects of Different Shielding Gases in Laser Welding of Secondary Ni battery with Multi-thin Plates (이차전지용 니켈 다층 박판의 레이저 용접 보호가스의 영향)

  • You, Young-Tae;Lee, Ka-Ram;Kim, Jin-Woo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.25 no.5
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    • pp.329-337
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    • 2016
  • The demand for the eco-friendly vehicles is skyrocketing because of the increasing $CO_2$ emissions and global warming. In the industrial field, the battery process, a core part of an eco-friendly vehicle, is drawing increased attention; its weight lightening as well as high energy density are becoming increasingly important. In this study, pure Ni plates that were used as the battery pole plate were welded using the laser. The lab joint welding was conducted on ten pure Ni plates at a laser power of 1900 W and a feed speed of 2.8-3.4 m/min. As observed in the experiment, a faster feed speed reduced the bead width, but the laser did not penetrate all ten specimen plates. In addition, pores were trapped when protective gas was used, but they were not trapped when the welding was conducted in atmospheric condition.

Functional Cerebrospinal Therapy (FCST), a New Physiologic Therapeutics Developed as Meridian Yin-Yang Balance Approach (침구경락 음양론의 새로운 발전, 기능적 뇌 척주요법 FCST)

  • Yin, Chang-Shik;Koh, Hyeong-Gyun;Lee, Young-Jin;Chun, Sae-Il;Lee, Young-Jun
    • Korean Journal of Acupuncture
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    • v.22 no.4
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    • pp.169-174
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    • 2005
  • Objectives : Functional Cerebrospinal Therapy (FCST) is a new physiologic therapeutics developed in Korea as a meridian yinyang balance approach. The theory of yinyang balance has been at the core of health enhancement approach of meridian and acupuncture medicine ever since its start. Methods : Introductory overview of FCST is presented in relation with meridian yinynag balance theory. Results : As the temporomandibular joint (TMJ) and related tissues have direct interconnection with brainstem proprioceptive or motor systems and the face is where all the meridians converge, FCST applies a fine adjustment of the posture of TMJ as a treatment tool for neurologic conditions or meridian imbalances. Conclusions : Highly sophisticated diagnostic and therapeutic techniques to adjust various subset aspects of yinyang balance are developed within FCST, which is supposed to be one of major contributions to natural healing.

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Clinical Approach of Chukyu Pharmacopuncture and Brainspotting Through a Traffic Accident Patient Case (교통사고 환자 증례를 통한 척유약침과 Brainspotting의 임상적 접근)

  • Lee, Do-Eun;Ha, Ji-Su;Park, Hyun-Mee;Youn, In-Ae;Seo, Joo-Hee
    • Journal of Oriental Neuropsychiatry
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    • v.32 no.3
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    • pp.261-273
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    • 2021
  • The purpose of this study was to introduce effects of Chukyu pharmacopuncture and Brainspotting on knee pain, headaches, and acute stress disorder of a patient with a traffic accident. We treated a patient with Chukyu pharmacopuncture and Brainspotting. Numerical rating scale (NRS), Range of Motion (ROM), Hyperextension Position (HEP), Effusion (Eff), Patella Compression Test (PCT), Frontal Flexion Position (FFP), McMurray (MCM), Lateral Joint Line Tenderness (LJLT), Medial Joint Line Tenderness (MJLT), Anterior Drawer Test (ADT), Lachman Test, Varus/Valgus stress, Beck Anxiety Inventory (BAI), Patient Health Questionnaire-9 (PHQ-9), Pittsburgh Sleep Quality Index (PSQI), Core Seven Emotions Inventory Short Form (CSEI-S), Subjective units of disturbance scale (SUDs), and Heart rate variability (HRV) were used to evaluate the patient. After the patient was treated by Chukyu pharmacopuncture and Brainspotting, the patient showed improvement in NRS, physical examination, and psychological symptom assessment. These results indicate that Chukyu pharmacopuncture and Brainspotting are effective on knee pain, headache, and acute stress disorder after a traffic accident.

Joint Design and Strength Evaluation of Composite Air Spoiler for Ship (선박용 복합재 에어 스포일러의 체결부 설계 및 강도 평가)

  • Pi, June-Woo;Jeon, Sang-Bae;Lee, Guen-Ho;Jo, Young-Dae;Choi, Jin-Ho;Kweon, Jin-Hwe
    • Composites Research
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    • v.28 no.4
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    • pp.219-225
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    • 2015
  • Air spoiler, which can reduce the drag during operation, can be considered as a possible means to reduce carbon dioxide emission and to increase fuel efficiency. In this study, a composite air spoiler was designed and tested by static and repeated loads. The Green Water Pressure of 0.1 MPa a ship experiences during operation was perpendicularly applied to the air spoiler. Air spoiler was manufactured with sandwich panel which has glass fabric face and balsa core. Multiple sandwich panels were assembled to steel frame by bolt joint. The joint was designed to have bearing failure and examined by static and fatigue tests. Tests showed that the designed joint has enough margin of safety to endure joint failure. The developed sandwich panel to air spoiler is planned to be applied to a large scale commercial ship.

Inelastic Behavior of Post-tensioned Wide Beam System with different Reinforcement ratios within Column core (포스트텐션을 도입한 넓은 보에서 기둥 폭 내부에 배근된 보강재의 정착비에 따른 비탄성 거동 평가)

  • Choi Yun-Cheul;Lim Jae-Hyung;Moon Jeong-Ho;Lee Li-Hyung;Kwon Ki-Hyuk
    • Journal of the Korea Concrete Institute
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    • v.17 no.1 s.85
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    • pp.85-94
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    • 2005
  • Post-tensioned Precast concrete System(PPS) consists of U-shaped precast wide beams and concrete column. The continuity of beam-column joint is provided with floor concrete cast on the PC shell beam and post-tensioning. The purpose of this paper is to evaluate the response of PPS interior beam-column joint subjected to cyclic lateral loading. To this end, an experimental investigation was performed with three half-scale specimens of interior connection. The design parameters are the amount of beam reinforcement placed inside the joint core. The test results showed that cracks were distributed well without my significant degradation of strength and ductility. Also, it was found that the prestressing may affect to alter the torsional crack angle. And the specimens sufficiently resist up to limiting drift ratio of 0.035 in accordance with the provisional by ACl of acceptance criteria for concrete special moment frames.

Effect of Brazing Condition on Tensile Properties in Brazing Joints of Inconel-625/Ni-201 Using MBF-30 (MBF-30을 사용한 Inconel-625/Ni-201 브레이징 접합부의 인장성질에 미치는 접합조건의 영향)

  • Yu, Jeong-Woo;Park, Sang-Hyun;Kim, Chang-Su;Kang, Chung-Yun
    • Journal of Welding and Joining
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    • v.30 no.6
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    • pp.106-112
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    • 2012
  • This study was carried out to investigate the effect of bonding temperature and holding time on microstructure and mechanical properties in brazing joints of Ni-base superalloy using MBF-30 (Ni-4.5Si-3.2B [wt.%]). The heating rate was $20^{\circ}C$/min to the bonding temperatures $1050^{\circ}C$, $1070^{\circ}C$, $1090^{\circ}C$ under high vacuum condition. The holding times were 100s, 400s, 900s and 1600s. $Ni_3B$ phases and proeutectic Ni were observed in the interlayer of Ni-201. Then, Ni3B and Ni3Si were found in the middle region of brazing joint. Cr-boride phase appeared in the interlayer of Inconel-625. Tensile strength and elongation were decreased at $1050^{\circ}C$-1600s, $1070^{\circ}C$-900s and $1090^{\circ}C$-400s. After observation the fracture specimens, There was Ni3B which is very brittle phase in the grain boundary of Ni201.

Implication from Technology Innovation, Growth Strategy and Industrial Policy of Chinese Automobile Industry (중국 자동차 산업의 기술혁신, 성장전략 및 산업정책의 시사점)

  • Baek, Seoin;Lee, Seongmin;Chang, Hyunjoon
    • Knowledge Management Research
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    • v.17 no.2
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    • pp.75-101
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    • 2016
  • Since 2009, China has become biggest automobile supplier and consumer all over the world. Chinese government and automobile firms have been executed strategic and aggressive industry policy and business strategy for nurturing automobile industry as a core manufacturing industry. However, can we assure that all of these policy and strategy have positive effect on Chinese automobile industry? For fulfilling this gab, our research examined the government policy and firm's strategy in different development stage of Chinese automobile industry. According to research result, at initial stage(1983-1996), Chinese automobile industry has grown by technological learning and reverse engineering from Soviet Union, Japan and Germany. In rapid growing stage(1996-2009), Chinese automobile firms have succeed to develop and produce own brand product with 100% own technology. And this kind of quantum jump in technology development was conducted by joint venture policy and M&A strategy. However, at the fourth stage(2010-), Chinese government and firms have over invested and focused on Electric Vehicle manufacturing without developing core technology or SW. Overall, the old-fashioned policy and strategy module in manufacturing industry of China could have negative effect on its industry development.