Yasumitsu Tomita

Marymount University

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Co-Authors

Kiyoshi Hashimoto

Mie Chuo Medical Center

Naoki Osawa

Marymount University

Yoshihiro Deguchi

Xi'an Jiaotong University

Nobutaka Shinkai

Marymount University

Sadayoshi Chiaki

Shanghai Ship and Shipping Research Institute

Kei‐ichi Sugiyama

National Institute of Health Sciences

Junji Sawamura

Osaka University

Daisen Tsubouchi

Marymount University

Nobuyuki Yamaga

Marymount University

Tsuyotoshi Yamaura

Mitsubishi Heavy Industries (Germany)

Cooperative Institutions

Marymount University

Mitsubishi Heavy Industries (Germany)

The University of Tokyo

Osaka University

Keio University

Xi'an Jiaotong University

Tokushima University

California Maritime Academy

Mitsubishi Heavy Industries (Japan)

Mitsubishi Heavy Industries (Italy)

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Study on Heat Transfer Phenomena between the Combustion Flow Field and the Heating Plate during Line Heating Process (3rd Report)

Journal of the Society of Naval Architects of Japan (2001)

Yasumitsu Tomita Naoki Osawa Kiyoshi Hashimoto Nobutaka Shinkai Junji Sawamura

The transient 3-dimensional temperature distribution within the gas flame during line heating is measured in detail by a high performance L. I. F. measurement system. It has been found that the relative distribution of gas temperature around the torch is almost the same as that in spot heating. It has also been found that this relative distribution is almost unchanged regardless of the temperature increase in the steel plate. Thease results lead us to a new hypothesis that the relative distributions of gas temperature and local heat transfer coefficient around the torch remain unchanged and they are almost the same as those in spot heating during line heating process. A new method of heat input estimation for line heating process based on this hypothesis has been propounded.

Torch

Line (geometry)

10.2534/jjasnaoe1968.2001.190_479

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Citations (4)

Study of Deformation Mechanism and Strength Characteristics of Ship Structural Materials under Cyclic Loading Conditions (1st Report)

Journal of the Society of Naval Architects of Japan (1993)

Yasumitsu Tomita Kiyoshi Hashimoto Naoki Osawa Sadayoshi Chiaki

On the bases of the assumption that certain materials can be typed as visco elastic-plastic bodies, a constitutive equation for the stress-strain response of such materials was derived. Then, the correlation was investigated between fatigue limit and the stress at the transition point, the point where the deformation mechanism of the material changed from visco elastic into visco elastic-plastic behavior.Complete compression-to-tension load-controlled axial constant amplitude loading test progmam was performed for mild steel plane specimens. As a result, following two main points are obtained.1) The constitutive equation derived from the visco elastic-plastic model can satisfactory represent cyclic stress-strain response.2) Both fatigue limit and the stress at the transition point were obtained, and they were found to be almost identical.

Tension (geology)

Transition point

Constant (computer programming)

10.2534/jjasnaoe1968.1993.174_509

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Study on Fatigue Crack Initiation Process by Using Crystalline FEM analysis (4th Report)

Journal of the Society of Naval Architects of Japan (2001)

Naoki Osawa Yasumitsu Tomita Kiyoshi Hashimoto Nobuyuki Yamaga Ryo Yasunaga

The micromechanical hardening rules developed by the authors are employed in the FE analysis of cyclic hardening behaviour of a Cu single crystal. The validity of the presented theory is examined by comparing the changing nature of the hysteresis loop shape parameters of the simulation results and experimental results. The nature of non-uniform deformation in the crystal is also investigated.As results, the followings are found : i) The constitutive relation employed gives a good account of the changing nature of hysteresis loop of Cu single crystals qualitatively when the mutual trapping of dislocations into dipoles and multipoles is considered. ii) The Bauschinger energy parameter reaches its maximum when the finite secondary slip onsets. This leads to the assumption that PSB formation begins when the finite secondary slip arises. iii) The localization of secondary slip occurs even if there is not severe stress concentration. The stress redistribution caused by the onset of secondary slip in the area at which stress concentrates leads this phenomena.

Bauschinger effect

Hardening (computing)

10.2534/jjasnaoe1968.2001.190_539

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