• 제목/요약/키워드: Joints

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Creep-Rupture and Fatigue Properties of Transient Liquid Phase Bonded Joints of Ni-Base Single Crystal Superalloy (액상확산접합한 Ni기 단결정 초내열합금의 크리프 파단 및 피로특성)

  • 김대업
    • Journal of Welding and Joining
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    • v.19 no.1
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    • pp.82-87
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    • 2001
  • The creep-rupture and low cycle fatigue properties of transient liquid phase bonded joints of Ni-base single crystal superalloy, CMSX-2 was investigated using MBF-80 insert metal. The (100) orientation of bonded specimen was aligned perpendicular to the joint interface. CMSX-2 was bonded at 1523K for 1.8ks in vacuum, optimum bonding condition. The creep rupture strength and rupture lives of the joints were the almost identical to ones of the base metal. SEM observation of the fracture surfaces of joints after creep rupture test revealed that the fracture surfaces classified three types of region, ductile fracture surface, cleavage fracture surface and interfacial fracture surface. The low cycle fatigue properties of the joints were also the same level as those of base metal. The elongation and reduction of area values of joints were comparable to those of base metal while fell down on creep rupture condition of high temperature.

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Fatigue of Grout Type Transverse Joint

  • Kim, Yoon-Chil;Park, Jong-Jin
    • KCI Concrete Journal
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    • v.14 no.2
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    • pp.69-75
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    • 2002
  • This is the second of two part series on experimental studies of grout type transverse joints. In this paper, grout-type transverse joints between precast concrete slabs are tested to study the fatigue behavior. The tests are per-formed with loading equipment designed and constructed especially in the lab to introduce shear fatigue failures on the joints of the test specimens with repeated loads. Non-prestressed as well as prestressed specimens are selected based on static tests and these specimens are studied to identify the effect of prestress on the fatigue strength of the grout type joint. A comparison between prestressed and non-prestressed specimens indicates that longitudinal prestressing is an effective method to increase fatigue strength of the transverse joints. Based on the fatigue test, a rational estimation of the fatigue strength is proposed to aid design of the grout-type transverse joints.

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Analytical evaluation of the moment-rotation response of beam-to-column composite joints under static loading

  • da Silva, L. Simoes;Coelho, Ana M. Girao;Simoes, Rui A.D.
    • Steel and Composite Structures
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    • v.1 no.2
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    • pp.245-268
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    • 2001
  • The analysis of steel-concrete composite joints presents some particular aspects that increase their complexity when compared to bare steel joints. In particular, the influence of slab reinforcement and column concrete encasement clearly change the moment-rotation response of the joint. Starting from an energy approach developed in the context of steel joints, an extension to composite joints is presented in this paper that is able to provide closed-form analytical solutions. In addition, the possibility of tri-linear or non-linear component behaviour is also incorporated in the model, enabling adequate treatment of the influence of cracked concrete in tension and the softening response of the column web in compression. This methodology is validated through comparison with experimental tests carried out at the University of Coimbra.

Behavior of exterior reinforced concrete beam-column joints including a new reinforcement

  • Fisher, Matthew J.;Sezen, Halil
    • Structural Engineering and Mechanics
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    • v.40 no.6
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    • pp.867-883
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    • 2011
  • Six reinforced concrete beam-column joint specimens were constructed and tested under reverse cyclic loading to failure. The six specimens were divided into three groups, each group representing a different joint design. The main objectives of this study are to investigate the response of joints with three different design, reinforcement detailing and beam strengths, and to evaluate and compare the responses of beam-column joints reinforced with traditional steel rebar and a recently proposed steel reinforcement called prefabricated cage system (PCS). Each of the three test specimen designs included equivalent amount of steel reinforcement and had virtually identical details. The results of the research show that the PCS reinforced joints had a slightly higher strength and significantly larger deformation capacity than the equivalent rebar reinforced joints.

A new experimental technique on the tubular joints of spatial grid structures

  • Chen, Zhi-Hua;Sun, Guo-Jun;Luo, Zhi-Shan
    • Structural Engineering and Mechanics
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    • v.40 no.6
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    • pp.801-811
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    • 2011
  • A new experimental technique was developed on the plate-inserted welded tubular joints of spatial grid structures. In the experimental technique, a microcomputer controlling instrument of moire intervention (MCIMI) was adopted. A test was designed on the plate-inserted welded tubular joints of spatial grid structures to show the effectiveness of the MCIMI technique. Both traditional electrical measuring technique and MCIMI technique were employed in the test. The test results showed that the MCIMI technique was feasible in the case of the complicated tests on steel structures. The MCIMI technique not only implemented the limitation of traditional electrical measuring technique, but also improved the accuracy of the test. According to the test results, we further examined the plate-inserted welded tubular joints in the cable-stayed spatial grids of the Binhai International Convention & Exhibition in Tianjin, China. The analysis showed the joints are safely designed with adequate conservatism. The research provided a new application of MCIMI in the field of large-scale structure engineering.

Analysis of Joint Behavior in Cement Concrete Pavements (시멘트 콘크리트 포장체 줄눈부의 거동해석)

  • 변근주;이상민;임갑주;한봉완
    • Proceedings of the Korea Concrete Institute Conference
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    • 1990.10a
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    • pp.1-6
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    • 1990
  • Joints are provided in cement concrete pavements to control transverse and longitudinal cracking that occur due to restrained deformations caused by moisture and temperature variations in the slab. But the construction of joints reduces the load-carrying capacity of the pavement at the joints, and pavements have beem deteriorated by cracks at the slab edges along the joints due to traffic loads. Therefore, it is important to analyze the behavior of joints accurately in the design of cement concrete pavements. In this study, the mechanical behavior of cement concrete pavement slabs is analyzed by the plate-finite element model, and Winkler foundation model is adopted to analyze the subgrades. The load transfer mechanism of joints are composed of dowel action, aggregate interlocking, and tied-key action, and the analytical program is developed using these joint models.

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Reliability analysis of the nonlinear behaviour of stainless steel cover-plate joints

  • Averseng, Julien;Bouchair, Abdelhamid;Chateauneuf, Alaa
    • Steel and Composite Structures
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    • v.25 no.1
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    • pp.45-55
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    • 2017
  • Stainless steel exhibits high ductility and strain hardening capacity in comparison with carbon steel widely used in constructions. To analyze the particular behaviour of stainless steel cover-plate joints, an experimental study was conducted. It showed large ductility and complex failure modes of the joints. A non-linear finite element model was developed to predict the main parameters influencing the behaviour of these joints. The results of this deterministic model allow us to built a meta-model by using the quadratic response surface method, in order to allow for efficient reliability analysis. This analysis is then applied to the assessment of design formulae in the currently used codes of practice. The reliability analysis has shown that the stainless steel joint design according to Eurocodes leads to much lower failure probabilities than the Eurocodes target reliability for carbon steel, which incites revising the resisting model evaluation and consequently reducing stainless steel joint costs. This approach can be used as a basis to evaluate a wide range of steel joints involving complex failure modes, particularly bearing failure.

Fatigue Fracture Behaviour of Hollow Section Joints

  • Lichun Bian;Lim, Jae-Kyoo
    • Proceedings of the KWS Conference
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    • 2001.10a
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    • pp.281-284
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    • 2001
  • Fatigue behaviour of eight different hollow section T-joints was investigated experimentally using scaled steel models. The joints had circular brace members and rectangular chords (CRHS). Hot spot stresses and the stress concentration factors (SCFs) were determined experimentally. Fatigue testing was carried out under constant amplitude loading in air. The experimental SCF values for CRHS joints were found to be between those of circular-to-circular (CCHS) and rectangular-to-rectangular (RRHS) hollow section joints. The fatigue strength referred to experimental hot spot stress was in reasonably good agreement with current fatigue design codes for tubular joints.

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Experimental Study on Circular Flange Joints in Tubular Structures (원형강관 플랜지 이음에 관한 실험적 연구)

  • Shin, Chang-Hoon;Han, Duck-Jen
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.4
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    • pp.119-127
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    • 2002
  • This paper presents a study of the behaviour of bolted circular flange joints in tubular structures. In the tests on nine circular flange joints, different tension forces was applied to the joints and bolt strains, displacements and strains in the joints have been measured. Bolt strain, contact force(prying force) between flanges and stress distribution in a joint have been studied. Different methods used for the design of circular flange joints are described.

SCFs in offshore two-planar tubular TT-joints reinforced with internal ring stiffeners

  • Ahmadi, Hamid;Imani, Hossein
    • Ocean Systems Engineering
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    • v.12 no.1
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    • pp.1-22
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    • 2022
  • The majority of tubular joints commonly found in offshore jacket structures are multi-planar. Investigating the effect of loaded out-of-plane braces on the values of the stress concentration factor (SCF) in offshore tubular joints has been the objective of numerous research works. However, due to the diversity of joint types and loading conditions, a number of quite important cases still exist that have not been studied thoroughly. Among them are internally ring-stiffened two-planar TT-joints subjected to axial loading. In the present research, data extracted from the stress analysis of 243 finite element (FE) models, verified against available numerical and experimental data, was used to study the effects of geometrical parameters on the chord-side SCFs in two-planar tubular TT-joints reinforced with internal ring stiffeners subjected to two types of axial loading. Parametric FE study was followed by a set of nonlinear regression analyses to develop six new SCF parametric equations for the fatigue analysis and design of axially-loaded two-planar TT-joints reinforced with internal ring stiffeners.