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Akita, Koichi; Miyashita, Daisuke*; Takeda, Kazuya*; Oya, Shinichi*; Shobu, Takahisa; Sano, Kenji*; Saito, Toshiyuki*
Nihon Zairyo Gakkai Dai-44-Kai X Sen Zairyo Kyodo Ni Kansuru Shimpojiumu Koen Rombunshu, p.46 - 50, 2010/07
Relaxation process of surface compressive residual stress during tensile or compressive loading on a laser peened aluminum alloy was investigated. The residual stress was measured by X-ray, synchrotron and neutron diffractions and analyzed by a finite element method. The relaxation process clarified in this study was described as follows. When the tensile loading was increased, plastic deformation was occurred at the tensile residual stress region that existed inside of the material to be balanced with the surface compressive residual stress. On the other hand, when the compressive loading was applied, the plastic deformation was started at the maximum compressive residual stress region located just beneath the surface. Because the plastic deformation of the inside of the material induced the redistribution of the residual stress in the sample, the surface compressive residual stress was relaxed prior to the surface yielding.
Takeda, Kazuya*; Oishi, Masayuki*; Akita, Koichi; Oya, Shinichi*; Sano, Kenji*; Saito, Toshiyuki*
Nihon Zairyo Gakkai Dai-44-Kai X Sen Zairyo Kyodo Ni Kansuru Shimpojiumu Koen Rombunshu, p.51 - 55, 2010/07
Effects of compressive residual stress on fatigue strength on a laser peened aluminum alloy were investigated. The changes of the compressive residual stress were measured using X-ray diffraction. The residual stress was relaxed at the first loading cycle and after that the residual stress was almost kept until the final fracture. The number of fatigue cycles to failure could be predicted quantitatively if the compressive residual stress after the first loading cycle was estimated.
Suzuki, Hiroshi; Moriai, Atsushi; Shimojo, Yutaka; Xu, P. G.; Shiota, Yoshinori; Akita, Koichi
no journal, ,
Diffractometer for residual stress analysis, called RESA, has been installed at JRR-3 (Japan Research Reactor No.3) guide hall in JAEA (Japan Atomic Energy Agency) since 1993 and the fundamental studies on the materials engineering have been performed using RESA. Recently, not only academic users but also industrial users are interested in using the neutron stress measurement for ensuring the reliability of mechanical components and the number of such users is rapidly increasing each year. To respond to the increase of users of RESA, RESA has been upgraded to improve efficiency and versatility, and RESA-2 has been installed at T2-3-2 beam port in JRR-3 guide hall as well. Current status of RESA-1 and RESA-2 will be introduced in the presentation.
Harjo, S.; Aizawa, Kazuya; Ito, Takayoshi; Arima, Hiroshi; Abe, Jun; Moriai, Atsushi; Kamiyama, Takashi
no journal, ,
no abstracts in English