• Title/Summary/Keyword: Pin-joint

Search Result 172, Processing Time 0.034 seconds

Fabrication of Tensegrity Modules for Spatial Structures (대공간 구조를 위한 텐세그리티 모듈 제작)

  • Lee, Seunghye;Jeong, Jinwoo;Ahn, Seungwhan;Lee, Jaehong
    • Journal of Korean Association for Spatial Structures
    • /
    • v.19 no.3
    • /
    • pp.61-68
    • /
    • 2019
  • A tensegrity module structure is suitable type for spatial structures. Because the tensegrity is composed of set of discontinuous compressive elements (struts) floating within a net of continuous tensile elements (cables), the system can provide the basis for lightweight and strong. However, despite the advantages of tensegrities, design and fabrication of the systems have difficulty because of form-finding methods, pin-connection and the control of prestress. In this paper, the new pin-connection method was invented to make the tensegrity module. The production process and practical implementation of uniformly compressed the tensegrity structures by using a UTM are described. Experiments showed the mechanical response and failure aspects of the tensegrity system.

Estimation of Indent Fracture due to the Moving Process of a Pin on PCB Plate (PCB 판에 대한 핀의 이동 공정에 따른 압입파괴 평가)

  • Kim, Young-Choon;Kim, Choon-Sik;Lee, Hee-Sung;Cho, Jae-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.15 no.12
    • /
    • pp.6967-6972
    • /
    • 2014
  • Assembly using a bolt and nut, and rivet or pin have been used widely for forming mechanical joints. The indent method is an easier process than other manufacturing techniques and the toughness of the material is excellent. On the other hand, there are many cases in which the cracks occur on the manufacturing process as the indent method. Therefore, two kinds of models, in which a pin goes into and out PCB plate in this study were developed using the CATIA program and finite element methods were performed using the ANSYS program. When a pin was passed through a PCB plate in cases 1 and 2, the maximum loads applied to the PCB plate were 79.708N and 90.277N, respectively. When the PCB plate came out of the pin in cases 1 and 2, the maximum loads were 63.783N and 33.75N, respectively. The damage prevention and durability can be improved by applying the study results to the design of real indentation.

Characteristics of Microwelded BLU CCFL Electrode in Terms of Glass Beading Heat Treatment Temperature (미세 용접된 BLU CCFL 전극의 유리비딩 열처리 온도에 따른 접합부 특성)

  • Kim, Gwang-Soo;Kim, Sang-Duck;Kwon, Hyuk-Dong
    • Journal of Welding and Joining
    • /
    • v.27 no.4
    • /
    • pp.73-78
    • /
    • 2009
  • Characterization of the microweld CCFL electrode for the TFT-LCD backlight unit was carried out in terms of the glass beading heat treatment conditions. We evaluate the weld zone and parent metal of the microweld CCFL electrodes that were exposed to simulated glass beading heat treatment. The CCFL electrode was composed of the cup made with pure Ni, the pin made with pure Mo and the lead wire made with Ni-Mn alloy. Each part of the electrode was assembled together by micro spot welding process and then the assembled electrodes were exposed to simulated glass beading temperatures of $700^{\circ}C,\;750^{\circ}C$ and $800^{\circ}C$. The microstructures of the microweld CCFL electrode were observed by using optical microscope, scanning electron microscope and EDS. Micro-tensile and microhardness test were also carried out. The results indicated that the grain coarsening in the HAZs(heat affected zones) for both the cup-pin weld and pin-lead wire were exhibited and the grain coarsening of the HAZ for the cup and the lead wire was more obvious than the HAZ of the pin. The micro-tensile test revealed that the fracture occurred at the cup-pin weld zone for all test conditions. The fracture surface could be classified into two parts such as pin portion and cup portion including weld nugget. The failure was seemed to be initiated from the boundary between nugget and pin through the weld joint. The result of the microhardness measurement exhibited that the relatively low hardness value, about 105HV was recorded at the HAZ of the cup. This value was about 50% less than that of the original value of the cup. The reduction of the microhardness was considered as the cause of the grain coarsening due to welding process. It was also appeared that there was no change in electric resistance for the standard electrodes and heat treated electrodes.

Solder Joint Reliability of Bottom-leaded Plastic Package (BLP 패키지의 솔더 조인트의 신뢰성 연구)

  • 박주혁
    • Proceedings of the International Microelectronics And Packaging Society Conference
    • /
    • 2002.05a
    • /
    • pp.79-84
    • /
    • 2002
  • The bottom-leaded plastic(BLP) packages have attracted substantial attention since its appearance in the electronic industry. Since the solder materials have relatively low creep resistance and are susceptible to low cycle fatigue, the life of the solder joints under the thermal loading is a critical issue for the reliability The represent study established a finite element model for the analysis of the solder joint reliability under thermal cyclic loading. An elasto-plastic constitutive relation was adopted for solder materials in the modeling and analysis. A 28-pin BLP assembly is modeled to investigate the effects of various epoxy molding compound, leadframe materials on solder joint reliability. The fatigue life of solder joint is estimated by the modified Coffin-Hanson equation. The two coefficients in the equation are also determined. A new design for lead is also evaluated by using finite element analysis. Parametric studies have been conducted to investigate the dependence of solder joint fatigue life on various package materials.

  • PDF

Failure Behavior of Pin-jointed Carbon/Epoxy Composites using Acoustic Emission (음향방출법을 이용한 탄소섬유/에폭시 복합재의 핀 체결부 파괴거동)

  • Kim, Chan-Gyu;Hwang, Young-Eun;Yoon, Sung-Ho
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2011.11a
    • /
    • pp.520-522
    • /
    • 2011
  • In this paper, the bearing strengths and fracture behaviors of the pin-jointed carbon fiber/epoxy composites were investigated through pin loading test. The composites were fabricated by a filament winding process, and two types of laminated patterns were considered. According to the results, type 1 pattern revealed a net-tension failure mode, whereas type 2 pattern exhibited a bearing failure mode. Also, acoustic emission energy of the type 2 pattern was higher than that of the type 1 pattern. Therefore, the type 2 pattern was found to be structurally safer than the type 1 pattern.

  • PDF

Weldability and properties of lap joints by pin FSW with 1050 Al sheet (1050 Al판재의 핀 마찰 교반용접에 의한 실험적 연구)

  • Jang, Seok-Ki;Park, Jong-Seek;Han, Min-Su
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.31 no.4
    • /
    • pp.394-400
    • /
    • 2007
  • The properties and weldability of lap joints by PFSW with 1050 Al sheet was investigated according to tool shape. dimension and welding condition. Tensile shear test was carried out for lap jointed specimen, and the hardness in the joint regions was examined. Moreover interfacial joining length, metallograph and failure location of the lap-jointed cross section were discussed. Two tool types were a simple cylindrical type and a notched cylindrical type. Under joining conditions such as plunging depth of 2.2mm. rotating speed of 1600rpm and dwelling time of 3s, the tensile shear strength of lap-jointed specimen by the notched type tool was superior to that by simple cylindrical type tool. The maximum tensile shear load of lap jointed specimen was 5807N. Optimal dimensions of the notched type tool were as follows : diameters of the shoulder and pin were $18{\phi}mm$ and $10{\phi}mm$, and pin length was 2.2mm.

Failure of Cross-Pin Femoral Fixation after Anterior Cruciate Ligament Reconstruction - A Case Report - (전방십자인대 재건술후 대퇴골 경골핀 고정의 실패 - 증례보고 -)

  • Lee Kee-Byoung;Kwon Duck-Joo;Ji Yong-Nam
    • Journal of the Korean Arthroscopy Society
    • /
    • v.7 no.1
    • /
    • pp.92-95
    • /
    • 2003
  • A 34-year-old man with ACL total rupture due to slip down injury, had received ACL reconstruction using autogenous hamstrings tendon with cross-pin femoral fixation. Postoperative course was as usual. But postoperative 3 months later, he complained posterolateral knee pain, recurrent effusion and mild instability. He was managed repeatitive aspiration and nonsteroid antiinflammatory drugs but was failed to relieve symptoms & signs. In CT scans, perforation of posteromedial femoral cortex of lateral femoral condyle was found. In second look arthroscopy, two pieces of broken femoral cross pin were found in between tibiofemoral Joint which was badly injured cartilage. We considered malposition of pins was the main cause of failure. We propose that femoral tunnel must be made more acute angle and femoral cross-pin guide must be positioned more external rotation 10-20 degree than transepicondylar axis made confirm the cross-pin tunnel position in order to avoid posterior cortex perforation and early failure.

  • PDF

Dynamic Characteristics of Link Mechanism with Clearance (간극이 있는 링크기구의 동특성)

  • 최연선;배성준
    • Journal of KSNVE
    • /
    • v.9 no.5
    • /
    • pp.1050-1057
    • /
    • 1999
  • The existence of clearance at the link joint of a machine is inevitable for assembly and mobility. During the cyclic operation of a machine, rapid changes of the direction and magnitude of connection forces cause momentary loss of contact between the pin and the bushing at the link joint. Contact loss at the clearance joint gives rise to undesirable impact. The impulsive force affects on the performance of the machine, and leads to excessive vibration, noise and faster wear in the connecitons. In this paper, experiment and theoretical analysis were carried out for the variation of crank speed and clearance size. The link mechanism employed in this investigation was newly designed to check the effects of parameter changes on the occurrence of contact loss and on the magnitude of the impact force. The contact loss and impact position were calculated with various driving conditions.

  • PDF

Studies on Evaluation for Long-term Loading of Composite Wood-joint and Characteristics of Joint Strength (I) - The strength properties of mechanical joints of Pinus densiflora with drift pin and bolt - (목재 접합부의 강도특성 및 장기 내력 평가 (I) - 소나무재의 Bo1t 및 Drift pin 접합부 능력(耐力) 성능 평가 -)

  • Hong, Soon-Il;Hwang, Won-Jung;Kim, Eun-Sam;Jin, Kwang-Sung
    • Journal of the Korean Wood Science and Technology
    • /
    • v.29 no.4
    • /
    • pp.1-8
    • /
    • 2001
  • This study was carried out to investigate the strength and stiffness of drift pinned and bolted joints with steel-plates by the tension-type lateral strength tests. Specimens were solid wood of Pinus densiflora. Bolt and drift pin were jointed with inserted steel plates. Tests were conducted with combinations of two loading directions (parallel to the grain : 0 degree, perpendicular to the grain : 90 degree) and three diameters of fasteners (d = 6 mm, 10 mm, 12 mm). The results obtained were as follow: 1. In the test of the parallel to the grain, maximum loads were increased with increasing of the diameter of bolt and drift pin in the same end distance. In the test of perpendicular to the grain with diameter 10 mm and 12 mm, specimens mostly were failed with horizontal splits in woods reaching the yield load of drift pinned and bolted joints. 2. The ratio of maximum load to the yield load determined by the so-called "5% offset method", was great in bolted joints in the parallel to the grain This trend become more remarkable as the slenderness ratio was increased. 3. The calculated yield strength was agreed well with the experimental results of drift pinned joint(0 degree).

  • PDF

A study on the strength of mechanically fastened composite joint using the linear analysis (선형해석을 이용한 복합재료 기계적 체결부의 강도평가에 관한 연구)

  • Chun, Young-Jun;Choi, Jin-Ho;Kweon, Jin-Hwe;Lee, Sang-Chan
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.32 no.9
    • /
    • pp.49-56
    • /
    • 2004
  • With the wide application of fiber-reinforced composite material in aero-structures and mechanical parts, the design of composite joint have become a very important research area because they are often the weakest areas in composite structures. In this paper, the linear finite element analyses in which the pin of the composite joint was assumed to be the frictionless rigid body were performed and predict the strength of the mechanically fastened composite joint using the failure area index method. By the failure area index method, the strength of the mechanically fastened composite joint which has the specimen of different shape, hole size and stacking sequence could be predicted within 12.2%.