• 제목/요약/키워드: mechanical joint

검색결과 2,028건 처리시간 0.03초

Design Optimization of Double-array Bolted Joints in Cylindrical Composite Structures

  • Kim, Myungjun;Kim, Yongha;Kim, Pyeunghwa;Park, Jungsun
    • International Journal of Aeronautical and Space Sciences
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    • 제17권3호
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    • pp.332-340
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    • 2016
  • A design optimization is performed for the double-bolted joint in cylindrical composite structures by using a simplified analytical method. This method uses failure criteria for the major failure modes of the bolted composite joint. For the double-bolted joint with a zigzag arrangement, it is necessary to consider an interaction effect between the bolt arrays. This paper proposes another failure mode which is determined by angle and distance between two bolts in different arrays and define a failure criterion for the failure mode. The optimal design for the double-bolted joint is carried out by considering the interactive net-tension failure mode. The genetic algorithm (GA) is adopted to determine the optimized parameters; bolt spacing, edge distance, and stacking sequence of the composite laminate. A purpose of the design optimization is to maximize the burst pressure of the cylindrical structures by ensuring structural integrity. Also, a progressive failure analysis (PFA) is performed to verify the results of the optimal design for the double-bolted joint. In PFA, Hashin 3D failure criterion is used to determine the ply that would fail. A stiffness reduction model is then used to reduce the stiffness of the failed ply for the corresponding failure mode.

스플라인결합 조인트의 볼트 예하중에 대한 유한요소 해석 (FEM Analysis of the Spline Joint with Bolt Pre-load)

  • 탁승민;강민규;박동진;이석순
    • 한국정밀공학회지
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    • 제28권11호
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    • pp.1316-1322
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    • 2011
  • Most of the mechanical structures use bolting or spot welding for the whole structure. In recent years, bolting & rivets are used rather than the welding due to reassembly and repair. Analysis of bolted joints is so complicate that many conditions must be considered such as pre-load and contact, etc.. Bolted joint analysis is done by theoretical, experimental & numerical methods. However, numerical analysis in the bolted joint is used because the contact and stress in the joints are changed due to the pre-load. In this study, we analysis the slip and the deformation of the contact area in the joint depending on the pre-load and find the optimized bolting condition.

세라믹-금속 브레이징 접합조인트의 고온 접합강도에 관한 연구 (High Temperature Flexural Strengths of the Ceramic-Metal Brazed Joints)

  • 이수정;정명영;이대길;구형회
    • 대한기계학회논문집A
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    • 제20권2호
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    • pp.520-528
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    • 1996
  • Four point bending tests of the brazed joint composed of sintered silicon nitride and 0.2% carbon steel with Cusil ABA filler which were fabricated at 86$0^{\circ}C$ were performed at temperatures, 25, 100, 200, 300, 400, 50$0^{\circ}C$ From the experiments, the maximum bending strength was measured at 30$0^{\circ}C$ From the 3D FE analysis of the residual stress of the brazed joint, it was revealed that the thermally induced residual stresses were minimized when the environmental temperature was 35$0^{\circ}C$ Considering the degradation of the filler material at high temperatures, it was calculated that the maximum bending strength of the brazed joint occured just below the temperature of the minimum thermal residual stress and the thermal residual stress was the dominative parameter of the brazed joint.

무릎관절 재활기구에 관한 연구 (A Study on the Rehabilitation Equipment for Knee Joint)

  • 이귀형;김용진;박석현;이효성;조현아
    • 한국생산제조학회지
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    • 제22권3_1spc호
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    • pp.509-517
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    • 2013
  • This paper presents upgraded equipment to assist a patient in rehabilitating of their knee-joint by themselves. A new automatic mechanism is suggested and developed in order to add functions for enforcing the leg muscles, which were absent in previous rehabilitation machines. Using the Pro-engineer software, we analyze the displacements and speeds of several moving points of the equipment during various planned exercises. In addition, an appropriate control panel for operation is developed. Three motors andthree motor drivers are used in a tilting part for the ankle joint, sliding guide part for the knee joint, and up-down moving part for the whole leg. Finally, various newly upgraded motions can be generated by controlling the three motors simultaneously. we show that by using this equipment, we can adjust the proper length of the equipment according to the user's height and the intensity of the rehabilitation exercise.

PD 검출을 통한 케이블 접속부 진단 (Diagnosis of cable joint by PD detection)

  • 이성희;이진희;이왕하
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 A
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    • pp.554-556
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    • 2002
  • It has little possibility that cable and cable joint causes any problem in transmission system. But when cable fault occurs, the damage is very severe. There are weak points to have potential problem due to many cable joint especially in high voltage transmission line. In this study, we propose nobel method to detect PD in cable joints and show the effectiveness of the proposed method through experiment results.

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Friction Stir Welding Tool Geometries Affecting Tensile Strength of AA6063-T1 Aluminum Alloy Butt Joint

  • Kimapong, Kittipong;Kaewwichit, Jesada;Roybang, Waraporn;Poonnayom, Pramote;Chantasri, Sakchai
    • International journal of advanced smart convergence
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    • 제4권1호
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    • pp.145-153
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    • 2015
  • Friction Stir Welding (FSW) is a solid state welding that could successfully weld the difficult-to-weldmaterials such as an aluminum alloy. In this welding process, the stirrer of the welding tool is one of the important factors for producing the perfect sound joint that indicates the higher joint strength. So, this report aims to apply the friction stir welding using various stirrer geometries to weld the AA6063-T1 aluminum alloy butt joint, investigates the mechanical properties of the joint and then compares the mechanical properties with the microstructure of the joint. An experiment was started by applying the friction stir welding process to weld a 6.3 mm thickness of AA6063-T1 aluminum alloy butt joint. A study of the stirrer geometries effect such as a cylindrical geometry, a cone geometry, a left screw geometry and a right screw geometry at a rotational speed of 2000 rpm and a welding speed of 50-200 mm/min was performed. The mechanical properties such as a tensile strength and a hardness of the joint were also investigated and compared with the microstructure of the joint. The results are as follows. A variation of FSW Stirrer shape directly affected the quality AA6063-T1 aluminum alloy butt joint. A cylindrical stirrer shape and a cone stirrer shape produced the void defect at the bottom part of the weld metal and initiated the failure of the joint when the joint was subjected to the load during the tensile test. Left and right screw stirrer shapes gave the sound joint with no void defect in the weld metal and affected to increase the joint strength that was higher than that of the aluminum base metal.

590MPa급 고강도강 플래시버트 용접이음부의 기계적특성 (Mechanical Properties of the Flash Butt Welded Joint of 590MPa High Strength Steel)

  • 정보영;우인수;김정길;이종봉
    • Journal of Welding and Joining
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    • 제25권2호
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    • pp.55-61
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    • 2007
  • Flash butt weldability of 590MPa dual phase steel is carried out under micro metallographical examination and macro mechanical property tests. The objective of present study is to investigate the cause that brings on bond line fracture, and is to improve mechanical properties of the flash butt welded joint. The joint of flash butt welding has a superior tensile property, but has bad formability due to oxide formed at bond interface. The HAZ softening in the weld joint does not show. It was found that mechanical properties were increased with optimizing welding parameters and making application of oil dripping and post-weld heat treatment.

인간형 로봇관절의 개발 (Development of Anthropomorphic Robotic Joint)

  • 류성무;백상훈;최혁렬
    • 대한기계학회논문집A
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    • 제25권1호
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    • pp.89-97
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    • 2001
  • In this paper, we present a new two-dof anthropomorphic joint mechanism that enables to mimic the humanlike motion. The proposed mechanism, called Double Active Universal Joint(DAUJ), generates a two-dof swivel motion without rolling by the coupled motion of two independent motor. In addition, we perform basic experiments to confirm the effectiveness of the proposed mechanism and the results are reported.

육면형 병렬기구에서의 조인트 오차의 영향 (Effect of Joint Errors in a Cubic Parallel Device)

  • 임승룡;최우천;송재복;홍대희
    • 한국정밀공학회지
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    • 제18권6호
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    • pp.87-92
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    • 2001
  • An error analysis is very important for a precision machine to estimate its performances. This study proposes a new parallel device, cubic parallel manipulator. Errors of the proposed cubic parallel manipulator include upper and down universal joint errors, due to the directional changes in the forces in the links, and actuation errors. An error analysis is presented based on an error model formed through the relation between the universal joint errors of the cubic parallel manipulator and the end effector accuracy. The analysis shows that the method can be used in predicting the accuracy of other cubic parallel devices.

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인공관절용 초고분자량폴리에틸렌의 가교결합 공정변수와 기계적 특성과의 상관관계 (Relationship between Crosslinking Processes and Mechanical Properties of UHMWPE for Artificial Joint)

  • 김현묵;김성곤;이종대;윤인식
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1570-1574
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    • 2008
  • Various mechanical test were conducted on conventional and crosslinked ultra-high molecular weight polyethylene(UHMWPE) all prepared from the same lot of medical grade GUR 1050 for artificial joint. The conventional materials were not irradiated and treated by heating. The cosslinked materials were irradiated with $25kGy{\sim}200kGy$ by gamma-ray andthen annealed or remelted. Gamma-ray irradiation and heat treatment process were found to significantly impact the crystallinity, and hence the mechanical behavior, of the highly crosslinked UHMWPE. The radiation dose and heating conditions were key predictors of the uniaxial yielding, plastic flow, and failure properties of conventional and highly crosslinked UHMWPE. The correlation model from experiments would be the basic information to enhance the were resistance of artificial joint liner.

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