Papers - OBATA Makoto
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A rigorous method for the analysis of localization behavior of compression plate Reviewed
Y. GOTO, Q. WANG, M. OBATA
J. Structural Mechanics and Earthquake Engineering, JSCE 543 55 - 70 1996.04
Language：Japanese Publishing type：Research paper (scientific journal)
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Localization of axisymmetric buckling patterns of cylindrical shells under cyclic loading Reviewed
Y. GOTO, Y. TOBA, K. ONO, M. OBATA
Proc. Of JSCE 543 41 - 53 1996.04
Language：Japanese Publishing type：Research paper (scientific journal)
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Bending fracture of steel fiber reinforced concrete beam Reviewed
K. Hioki, T. UEHARA, M. OBATA, Y. NOBUTA
J. of JCI 18 ( 2 ) 1415 - 1420 1996.04
Language：Japanese Publishing type：Research paper (scientific journal)
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Ultimate behavior of tie plates at high-speed tension Reviewed
M. OBATA, Y. GOTO, S. MATSUURA, H. FUJIWARA
J. of Struct Engrg. 122 416 - 422 1996.04
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
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Modeling of ultimate behavior of stgeel pier-to-footing connections Reviewed
Y. GOTO, T. KAMIJO, H. FUJIWARA, M. OBATA
J. Struct. Engineering, JSCE 42A 987 - 998 1996.04
Language：Japanese Publishing type：Research paper (scientific journal)
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Ultimate behavior of the plates at high-speed tension Reviewed
M Obata, Y Goto, S Matsuura, H Fujiwara
JOURNAL OF STRUCTURAL ENGINEERING-ASCE 122 ( 4 ) 416 - 422 1996.04
Language：English Publishing type：Research paper (scientific journal) Publisher：ASCE-AMER SOC CIVIL ENG
Tie plates are integral components of pin connectors, lifting modules, and bridge restrainers. As a bridge restrainer, they are supposed to bear the dynamic seismic loads. In a previous work (Obata et al. 1991), the writers elucidated the ultimate behaviors of tie plates under quasi-static loading by the experiments and the numerical analysis. The objective of this work is to investigate the ultimate behaviors of tie plates at high-speed tension both experimentally and numerically. The high-speed tension experiments showed that the maximum strength increases with the increase of the tensile velocity. On the other hand, the deformation at the load maximum point is relatively insensitive to the tensile velocity. Therefore, the quasi-static test results always give the conservative values for the design. The numerical analysis is based on the J(2) power law strain-rate-dependent plasticity theory. Despite the simplification of the complex phenomena, the numerical results give useful insights into the experimental results and in the meantime serve as reliable tools for a rational design of these tie plates.
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Localization of plastic buckling patterns of plates and cylindrical shells under cyclic loading Reviewed
Y Goto, QY Wang, K Ono, M Obata
ADVANCES IN STEEL STRUCTURES, VOLS 1 AND 2 869 - 874 1996
Language：English Publishing type：Research paper (international conference proceedings) Publisher：PERGAMON PRESS LTD
This paper theoretically investigates the localization of plastic buckling patterns in compression plates and cylindrical shells because this phenomenon has a large influence on the strength deterioration under cyclic loading. The localization behavior is caused by a plastic bifurcation on the decreasing equilibrium path subsequent to the maximum load point. Thus, we first show a rigorous numerical method based on the finite-element method technique to analyze the plastic bifurcation. Then, using this method, we examine the localization behavior of rectangular compression plate and that of the axisymmetric cylindrical shells under cyclic loading, Specifically, we investigate how the structural parameters and constitutive models affect the strength deterioration.
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Analysis of the ultimate behavior of a slit-type bridge restrainer Reviewed
M Obata, T Kurihara, Y Goto
ADVANCES IN STEEL STRUCTURES, VOLS 1 AND 2 1 559 - 564 1996
Language：English Publishing type：Research paper (international conference proceedings) Publisher：PERGAMON PRESS LTD
The prevention of the falling out of girders is one of the important issues of the seismic design for highway bridges. A bridge restrainer is a structural element designed for this particular purpose that constraints the displacement by tying a girder to adjacent girders or piers during earthquake. The Hyogoken-Nanbu earthquake was the first major earthquake that the modern bridge restrainers have experienced since their installation. Unfortunately, some of them were destroyed to lead the falling out of girders. The objective of this work is to propose a new type bridge restrainer for steel bridge girders after the lessons of the disaster. The behaviors of the new type restrainers are investigated by Finite Element Analysis to give the fundamental basis of the rational design of them.
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Experiment on cyclic behavior of steel column to base connections with double anchor beams Reviewed
Y. GOTO, K. HIBI, T. KAMIJO, H. FUJIWARA, M. OBATA
J. Struct. Engineering, JSCE 41A 1137 - 1143 1995.04
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Ultimate behaviors of tie plates under quasi-static and high speed loading Reviewed
M. OBATA, H. FUJIWARA, S. MATSUURA
Proc. the 4th PSSC 1 487 - 494 1995.04
Authorship：Lead author Language：English Publishing type：Research paper (international conference proceedings)
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Study on the fracture toughness of the fiber reinforced high strength concrete Reviewed
K. YUKI, T. UEHARA, M. OBATA, Y. NOBUTA
J. of JCI 17 ( 1 ) 445 - 450 1995.04
Language：Japanese Publishing type：Research paper (scientific journal)
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Analysis of Greenhill problem by a co-rotational method Reviewed
Y. GOTO, Xiao-Song LI, T. KASUGAI, M. OBATA
J. Struct. Engineering, JSCE 41A 411 - 420 1995.04
Language：English Publishing type：Research paper (scientific journal)
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Y. GOTO, N. KAWANISHI, Y. TOBA,M. OBATA
J. Structural Mechanics and Earthquake Engineering, JSCE 483 ( 483 ) 87 - 96 1994.04
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers
In case of structures under compressive loading, it is often observed experimentally that the ductility of structures is considerably lost due to the localization of plastic buckling patterns. This implies that the phenomena of this kind has an unfavorable effect on the earthquake resistance. Herein, we present a versatile theoretical method to analyze the localization of buckling patterns including that under cyclic loading. As numerical examples, two types of structures, i. e. a multiply supported column and a truss tower under compressive force, are analyzed in order to show the validity of the proposed method. In these examples the cyclic localization phenomena is also discussed in terms of the influence on deformation capacity.
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On the behavior of the residual stresses near a notch after cyclic loadings Reviewed
M. OBATA, T. ITOH, Y. GOTO, S. MATSUURA
J. Struct. Engineering, JSCE 40A 135 - 142 1994.04
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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An advanced avaraging technique for multi-phase materials Reviewed
M.OBATA, Y.GOTO, S. MATSUURA
Proc. Of JSCE 459 ( 459 ) 63 - 71 1993.04
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers
It is an important and interesting problem to obtain averaged mechanical behaviors of multi phase composite materials. We propose an advanced averaging technique for three or more phase materials. The new technique, which we call Generalized Periodic (GP) method, borrows basic idea from two different existing schemes, a periodic structure and a self consistent method. The GP accounts for the interaction among the same phase inclusions by the model of periodic distributions, while the homogeneity of surrounding inhomogeneous matrix is assumed. Simple numerical examples show the character of GP method. GP's character is appreciable when the number of phase is relatively small and each volume fraction is large. On the other hand, when the number of phases increases, the GP's estimation of averaged behavior rapidly gets close to that of the self consistent method.
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Mechanical properties of bond type anchor bolt in situ experiment Reviewed
M.OBATA, Y.GOTO, H. MAENO, S. MATSUURA
J. of Construction Steel 1 801 - 806 1993.04
Language：Japanese Publishing type：Research paper (scientific journal)
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Failure mechanism of new bond-type anchor bolt subject to tension Reviewed
Y. GOTO, M. OBATA, H. MAENO, Y. KOBAYASHI
J. of Struct. Engrg. 119 ( 4 ) 1168 - 1187 1993.04
Language：English Publishing type：Research paper (scientific journal) Publisher：ASCE-AMER SOC CIVIL ENGINEERS
The objective of this study is to investigate the failure mechanism of a new bond-type anchor bolt under tensile force so that a design method may be established. A conventional headed anchor bolt embedded in a concrete footing normally fails by pulling out a stress cone; however, the bond-type anchor bolt exhibits a complex failure mode. here referred to as a mixed bond-cone failure. To date, the theoretical aspects of this failure mechanism have not been established. With the needs of design application in mind, an analytical model to predict the ultimate strength of the bond-type anchor bolt is presented. Experimental data confirm that this model can be used with acceptable accuracy to assess the ultimate strength and the failure mode of the bond-type anchorage system.
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Experiment on the ultimate strength of steel pier base fastened by bond-type anchor bolts Reviewed
H. MAENO, Y. GOTO, M. OBATA, Y. KOBAYASHI, S. MATSUURA
J. Struct. Engineering, JSCE 39A 1321 - 1334 1993.04
Language：Japanese Publishing type：Research paper (scientific journal)
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Bonding characteristics of a very large deformed bar with headed studs Reviewed
H. MAENO, Y. GOTO, M. OBATA, S. MATSUURA
Proc. Of JSCE 441 87 - 96 1992.04
Language：Japanese Publishing type：Research paper (scientific journal)
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A new bond-type anchorage system for steel piers Reviewed
Y. GOTO, H. MAENO, M. OBATA, Y. KOBAYASHI
Proc. PSSC 971 - 978 1992.04
Language：English Publishing type：Research paper (international conference proceedings)
