• Title/Summary/Keyword: Bolt Joints

Search Result 144, Processing Time 0.024 seconds

An Experimental Study on Behavior of Field Splice Joints of Longitudinal Rib in Orthotropic Steel Decks (강상판 종리브 현장연결부의 실험적 거동 특성)

  • Choi, Dong Ho;Choi, Hang Yong
    • Journal of Korean Society of Steel Construction
    • /
    • v.13 no.6
    • /
    • pp.621-629
    • /
    • 2001
  • This study consists of static and fatigue tests to evaluate the behavior on the field splice joint of longitudinal rib in orthotropic steel deck specimens. Specifically, static and influence surface tests are performed for the stress distribution at the scallop area and high-strength bolt connection of longitudinal rib to examine the existence of handhole cover plate and the effect of eccentric loads. The ultimate strength of the field splice joint of longitudinal rib is obtained. In fatigue tests, cracks are observed at the scallop in the lower level test and the catastrophic failure of longitudinal rib is occurred following the failure of handhole cover plate in the higher level test. This study gives a basis for the better understanding of the field splice joint of longitudinal rib.

  • PDF

The practice of blind bolting connections to structural hollow sections: A review

  • Barnett, T.C.;Tizani, W.;Nethercot, D.A.
    • Steel and Composite Structures
    • /
    • v.1 no.1
    • /
    • pp.1-16
    • /
    • 2001
  • Due to aesthetic, economic, and structural performance, the use of structural hollow sections as columns in both continuous moment resisting and nominally pinned construction is attractive. Connecting the beams to these sections is somewhat problematic as there is no access to the interior of the section to allow for the tightening of a standard bolt. Therefore, bolts that may be tightened from one side, i.e., blind bolts, have been developed to facilitate the use of site bolting for this arrangement. This paper critically reviews available information concerning blind bolting technology, especially the performance of fasteners in shear, tension, and moment resisting connections. Also provided is an explanation of the way in which the results have been incorporated into design guidance covering the particular case of nominally pinned connections. For moment resisting connections, it is concluded that whilst the principle has been adequately demonstrated, sufficient data are currently not available to permit the provision of authoritative design guidance. In addition, inherent flexibilities in the connections mean that performance equivalent to full strength and rigid is unlikely to be achievable: a semicontinuous approach to frame design will therefore be necessary.

Determination of Shock Response Spectrum Using FRF of Statistical Energy Analysis Method (통계적 에너지 분석법의 FRF를 이용한 충격 응답 스텍트럼(SRS)의 결정)

  • 구성완;황철규;김인성
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.14 no.7
    • /
    • pp.551-560
    • /
    • 2004
  • A method how to determine the shock response spectrum from the FRF of the statistical energy analysis( SEA ) is presented here. The system of 3 different Plates connected by bolt joints is selected simulating missile structural sections Joined together. First, the SEA model was rendered by SEA parameters which were determined from experimental SEA method. Then, the mobility power was input to the SEA model and we can verify the validity of the model in the medium to high frequency range checking the reproduction of output average velocity. And, the shock induced shock response spectrum(SRS) was obtained using SEA FRF and arbitrarily chosen experimental FRF. We have compared the thus obtained SRS with actually measured SRS and they were relatively in good agreement. In this paper, we used the measured SEA FRF and therefore we have got the SRS well agreed with actually measured SHS even in the low frequency range. If the SEA FRF of well verified SEA model is used, the good result will come out in SEA effective frequency range which is more important at SRS.

Connection Resistance of Mechanical Joint using Connection plate for Improvement of Connectivity between PHC piles (PHC파일간 연결 시공성 개선 이음판형 기계적 연결부의 연결저항)

  • Ahn, Jin-Hee;Moon, Hong-duk;Ha, Min-Gyun;Cho, Kwang-Il
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.23 no.7
    • /
    • pp.25-32
    • /
    • 2019
  • Welded joints and mechanical joints using bolt connection have been used as a pile-to-pile connecting method for PHC piles. These PHC pile joint methods may have difficulty in securing connecting quality and connecting performance in PHC pile joining process. Therefore, this study proposes a non-welded connection plate type mechanical PHC pile joint to improve the disadvantages of existing PHC pile connection methods and to secure the connection performance of PHC pile joint. Its connection performance was evaluated from nonlinear FE analysis and loading tests for actual PHC piles with suggested pile joints. From nonlinear FE analysis for the proposed PHC pile joint, it was evaluated to have sufficient connection performance under flexural, compressive, tensile, shear, and eccentric compressive load condition. PHC piles connected by the suggested connection plate type mechanical PHC pile joint show that they show stable linear behaviors for the crack moment and the flexural moment level of the PHC pile. Therefore, the proposed a non-welded connection plate type mechanical PHC pile joint can secure sufficient connection performance in PHC pile.

Effect of Chemical Composition of Nut Material on the Fracture Behavior in Nut Projection Welding of Hot-Stamped Steel Sheet (핫스탬핑강의 너트 프로젝션 용접시 너트 재질이 용접부 파단모드 변화에 미치는 영향)

  • Lim, Sung-Sang;Kim, Young-Tae;Chun, Eun-Joon;Nam, Ki-Sung;Park, Young-Wan;Kim, Jae-Wan;Lee, Sun-Young;Choi, Il-dong;Park, Yeong-Do
    • Journal of Welding and Joining
    • /
    • v.34 no.2
    • /
    • pp.1-10
    • /
    • 2016
  • The use of materials for modern lightweight auto-bodies is becoming more complex than hitherto assemblies. The high strength materials nowadays frequently used for more specific fields such as the front and rear sub frames, seat belts and seats are mounted to the assembled body structure using bolt joints. It is desirable to use nuts attached to the assembled sheets by projection welding to decrease the number of loose parts which improves the quality. In this study, nut projection welding was carried out between a nut of both boron steel and carbon steel and ultra-high strength hot-stamped steel sheets. Then, the joints were characterized by optical and scanning electron microscope. The mechanical properties of the joints were evaluated by microhardness measurements and pullout tests. An indigenously designed sample fixture set-up was used for the pull-out tests to induce a tensile load in the weld. The fractography analysis revealed the dominant interfacial fracture between boron steel nut weld which is related to the shrinkage cavity and small size fusion zone. A non-interfacial fracture was observed in carbon steel nut weld, the lower hardness of HAZ caused the initiation of failure and allowed the pull-out failure which have higher in tensile strengths and superior weldability. Hence, the fracture load and failure mode characteristics can be considered as an indication of the weldability of materials in nut projection welding.

Evaluation of Tensile Behaviors of Beam Splice with High Strength Bolts According to Steel Grades (강종에 따른 고력볼트 보 이음부 인장거동 평가)

  • Kim, Hee-Dong
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.21 no.1
    • /
    • pp.129-137
    • /
    • 2020
  • In designing a high strength bolted beam splice using steel for building structures, it is necessary to present the appropriate steel grade selection criteria for how to determine the cover plate steel grade. This study examined the difference in tensile behavior according to the steel grades through static tensile tests simulating the beam member high strength bolt joints flange. For this purpose, the specimens were designed and fabricated with the main variables, such as the thickness, steel grade and the strength of flange and cover plate, which are expected to affect the splice strength and behavior. The tensile test results for a total of 48 specimens showed that the tensile-load capacity exceeded the design tensile strength applied with a nominal strength of steel in all specimens. When the design strength of the cover plate exceeded 1.25 times that of the flange plate, the flange plate governed the behavior of splice. The change in maximum tensile load due to the change in flange steel grade is not very large, but there is a difference in deformation. The test results confirmed that the steel grade and thickness of the cover plate were the main factors affecting the beam splice behavior.

A Study on the Slip Behavior of Coated High Tension Bolted Joints (도장처리한 고장력볼트 연결부의 미끄러짐 특성에 관한 연구)

  • Kyung, Kab Soo;Lee, Seung Yong;Kim, Ki Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.28 no.5A
    • /
    • pp.691-697
    • /
    • 2008
  • Coating the high tension bolted frictional joint has been generally allowed for anti-corrosion purpose. However in case of painting on paying surface of the high tension bolt, the influence on a slip strength of the joint depending on precision of painting has remained controversial. The study thus was intended to identify the slip behavior on high tension bolted frictional joint when applying ceramic painting, which has been currently developed. A slip test was conducted on a high tension bolted frictional joint specimen on which ceramic painting has been applied and a slip load and slip coefficient were measured. Based on result, the safety and usability of ceramic painting-applied high tension bolted frictional joint was evaluated. As a result, a difference to some extent by specimen in terms of load-displacement when a slip occurred was observed but an average slip coefficient appeared to have exceeded 0.4, which is the design frictional coefficient set forth in the specification. To secure the safety and usability of ceramic painting-applied high tension bolted frictional joint, it's necessary to establish the standard for painting as well as to revise the relevant specification.

Seismic Tests of Steel Beam-to-column Moment Connections with Inclined End-plate Beam Splice (경사단부강판 보 이음을 갖는 강재 보-기둥 모멘트접합부의 내진실험)

  • Lim, Jong Jin;Kim, Dong Gwan;Lee, Sang Hyun;Park, Choul Soo;Lee, Chang Nam;Eom, Tae Sung
    • Journal of Korean Society of Steel Construction
    • /
    • v.29 no.2
    • /
    • pp.181-192
    • /
    • 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.

Initial Stiffness of Beam Column Joints of PCS Structural Systems (PCS 구조 시스템 접합부의 초기 강성에 대한 연구)

  • Park, Soon-Kyu;Kim, Moo-Kyung
    • Journal of the Korea Concrete Institute
    • /
    • v.20 no.3
    • /
    • pp.271-282
    • /
    • 2008
  • Specific joint devices composed of end-plates and through bolts are under development to assemble steel beams to PC columns efficiently by dry construction method for the PCS structural system, of which major structural components are precast concrete columns and steel beams. Seismic performance of the joint devices had been evaluated by experimental tests in the previous studies and it was showed that all the performance requirements regarding to strength deterioration, stiffness degradation and energy dissipation capacity were satisfied to the criteria of ACI requirements, but the initial stiffness was not. In order to find out possible causes of the insufficient rigidity of the joint devices and provide the proper measures to improve the performance of the joint accordingly, numerical analyses were carried out by using ABAQUS. Parameters, such as thickness of neoprene pad, conditions of surface between PC column and end-plate, magnitude of pretension forces of through bolts, stiffness of end-plate were taken into consideration. As the result, it was found that the rigidity of the PCS system was negatively affected by the magnitude of initial gaps between PC columns and end-plates, and insufficient stiffness of neoprene fillers and end plates. In order to improve the initial stiffness performance of the joints, measures such as increase of the magnitude of pretension forces on through bolts and increase of the stiffness of end-plate by reducing the bolt pitch and providing adequate stiffeners are recommended.

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.