Kou kouzou rombunshuu
Online ISSN : 1884-0329
Print ISSN : 1880-9928
ISSN-L : 1880-9928
Volume 16 , Issue 64
Showing 1-9 articles out of 9 articles from the selected issue
  • Katsunori KANEDA, Yoshihiro KIMURA, Yuta FUNATSU, Akira WADA
    2009 Volume 16 Issue 64 Pages 64_1-64_10
    Published: 2009
    Released: March 24, 2011
    JOURNALS FREE ACCESS
    There are some differences in the steel structures from the view of seismic design and practice between U.S., and Japan. In Japan all columns and beams are the seismic elements in X and Y directions. In U.S. frames in the perimeter zone are only the seismic elements, and the columns inside the building are designed as the gravity columns which support only the weight of the building. In our previous research, it is clarified that such gravity columns can control story drift concentration during an earthquake. We need more study about the effect of damage control for beams and columns by the gravity columns. We will discuss about the seismic limit capacity of the moment resisting frames when the beams or the columns reach their plastic deformation capacities.
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  • Samol YA, Kentaro YAMADA, Toshiyuki ISHIKAWA, Keita MURAI
    2009 Volume 16 Issue 64 Pages 64_11-64_20
    Published: 2009
    Released: March 24, 2011
    JOURNALS FREE ACCESS
    Fatigue evaluation of trough rib to deck weld joint failed in weld throat is presented. S-N curve of the joint is determined in term of stress range in weld throat by carrying out plate bending fatigue tests and collecting previous test data. Two approaches are proposed for calculating stress range in weld throat in actual bridge with orthotropic steel deck based on one or two points of measured stress. Both methods give approximate fatigue lives, suggesting one point of stress measurement is also possible in practice. By stress measurement at an actual bridge with orthotropic steel deck, stress range in summer tends to be higher and thus more damaging than in winter.
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  • Takeshi HANJI, Kazuo TATEISHI
    2009 Volume 16 Issue 64 Pages 64_21-64_30
    Published: 2009
    Released: March 24, 2011
    JOURNALS FREE ACCESS
    Steel bridge piers are often used for elevated highway bridges. The Hanshin-Awaji earthquake in 1995 revealed two types of failure mode in the pier, which are local buckling and low cycle fatigue. However, researches on low cycle fatigue of civil structures are limited, and design methods have not been established yet.
    In this study, low cycle fatigue strength curves for base joints of the steel pier based on nominal strain, which can be calculated by finite element analysis with a beam element, were proposed. Fatigue tests with steel pier specimens demonstrated that the proposed fatigue strength curves could provide fatigue life estimation with enough accuracy.
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  • Yoshitaka MIYAMOTO, Akihiko OBATA, Yasushi UEMATSU, Takuya NIGORIKAWA
    2009 Volume 16 Issue 64 Pages 64_31-64_40
    Published: 2009
    Released: March 24, 2011
    JOURNALS FREE ACCESS
    A new joint system named ‘elastic-hinge joint system’ is proposed. This system shows a non-linear elastic restoring force-rotation relation and can realize origin-oriented frames. These properties can control damage and reduce permanent distortion in structures or in structural elements after a severe earthquake. This paper describes experimental results on a beam-column connection to which this joint system is applied. The purpose of this paper is to clarify the separation and rotation behavior of the elastic hinge joint. Based on the results, a theoretical model of this joint system is proposed.
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  • Peng-bo ZHANG, Yuping SUN, Takashi FUJINAGA, Jae-hyouk CHOI
    2009 Volume 16 Issue 64 Pages 64_41-64_48
    Published: 2009
    Released: March 24, 2011
    JOURNALS FREE ACCESS
    Sixteen shear-type friction dampers were made and tested under cyclical loading to investigate the effect of the lap gap on the frictional resistance of the damper. The test results have indicated that the frictional resistance of a shear-type friction damper depends not only upon the tensile force by the high-strength bolts that clamp the slipping steel plate but also strongly upon the lap gap. Based on the experimental results, a formula for assessing the effect of the lap gaps on the frictional resistance of the damper was developed. Comparisons between the measured frictional resistances and the predicted ones have indicated that the frictional resistance of a shear-type friction damper with lap gap could be evaluated by the proposed formula very well.
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  • Yong Hun SONG, Hiroumi SHIMOKAWA, Takumi ISHII, Takahiko SUZUKI, Yoich ...
    2009 Volume 16 Issue 64 Pages 64_49-64_63
    Published: 2009
    Released: March 24, 2011
    JOURNALS FREE ACCESS
    This study describes fracture strength of electro-slag welded (ESW) connections under biaxial loading condition. The discussions are based on model test results of ESW joints and finite element analysis (FEA) results with corresponding analytical models. Case studies are also made where an axial force ratio and a penetration shape are the analytical parameters. Results are summarized as follows; 1) The model test results show roughly positive correlation between the fracture toughness and the fracture strengths of ESW joints; 2) The model test results and the corresponding FEA results correlate the fracture toughness with calculated equivalent maximum principal stress(MPA); 3) In the results of the case studies, the calculated MPA in a heat affected zone highly depends on an ESW fusion line position.
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  • Koji KINOSHITA, Shinpei ARAKAWA
    2009 Volume 16 Issue 64 Pages 64_65-64_70
    Published: 2009
    Released: March 24, 2011
    JOURNALS FREE ACCESS
    This paper investigates influence of incomplete penetration size on fatigue crack initiation points of load-carrying cruciform welded joints. The investigation was performed by fine meshed FEM using Effective Notch Stress Approach. As a result, to prevent fatigue crack initiated from welded root when the plate thickness is about 34mm, incomplete penetration size should be less than 10% of the plate thickness, and the influences of incomplete penetration size increase with an increase of the plate thickness. Also, a reduction of the stress at the weld root by increasing the weld size is not expected when the plate thickness is thick and welding becomes an unequal leg length welding.
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