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Volume 1989 (1989)
- Issue 140 Pages 222-
- Issue 139 Pages 175-
- Issue 138 Pages 133-
- Issue 137 Pages 81-
- Issue 136 Pages 2-
Volume 1989, Issue 137
Displaying 1-5 of 5 articles from this issue
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Kouichi Yasuda, Yohtaro Matsuo, Zuo Ming Wang, Shiushichi Kimura1989 Volume 1989 Issue 137 Pages 81-87
Published: April 20, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSRecently, we established a new theory by combining the statistical theory of fracture location with the competing risk theory. In this study, we developed new distribution functions of fracture stress and fracture location by assuming that a square cross-sectioned beam, which was composed of elastoplastic body, was subjected to three point bending load. It was found that there were some effects of the constitutive equation on distribution functions. We conducted three point bending test of polycrystalline graphites . Using our theory, we estimated shape parameters of Weibull distribution from fracture stress data, and also from fracture location data. Estimated values from fracture stress data coincided with the values from fracture location data fairly well.View full abstractDownload PDF (1225K) -
Miko Kaihara, Hiroaki Mametsuka, Naoki Gunji, Yohichi Gohshi1989 Volume 1989 Issue 137 Pages 88-92
Published: April 20, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe accuracy of a qualitative and a quantitative analysis in a FT-IR spectrum has been much disturbed because the large background of the spectra might hide the true absorption peaks. The problem of the disturbance caused by the large background in FT-IR spectra has remained unresolved since the backgrounds change much freely, depending on the subtle differences of sample preparation conditions. Therefore, the existences of the backgrounds has been said to be the very difficult problems to deal with. In our laboratory, a new characterization technique (scattering dilution method, SDM) has been investigated for solving the problems on the backgrounds. Our technique may become the clue to solve the problems and improve the accuracy of the qualitative and the quantitative analyses of pitches.View full abstractDownload PDF (672K) -
Akira Yoshida, Yoshihiro Hishiyama1989 Volume 1989 Issue 137 Pages 93-95
Published: April 20, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSKish graphite (KG) and highly oriented pyrolytic graphite (HOPG) were embedded in acetone at liquid nitrogen temperature, and were fractured with a knife-edge in liquid nitrogen. Fractured surfaces were observed by a scanning electron microscope with a low acceleration voltage. Well fractured regions have areas about 150μm length and about 10μm width for KG, and about 100μm length and about 10μm width for HOPG, for thelargest. The fractographs show a layered structure without regularity, in which thickness of the layer ranges between 0.05 and 0.2μm. The layered structure may be formed during complicated process induced in KG or HOPG crystal through fracture of solid acetone matrix.View full abstractDownload PDF (3331K) -
Shigeru Furukawa, Sugio Otani, Masao Miyamoto, Akira Kojima1989 Volume 1989 Issue 137 Pages 96-99
Published: April 20, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIt was tried to prepare unidirectional carbon-fiber/mortar using light weight sand composite (CFRC-L) (20 mm in thickness) and carbon-fiber/mortar using standard sandcomposite (CFRC-S) (20 mm in thickness) with long sheaf-type carbon fiber (CF) in tension side, and the mechanical properties of CFRC-L and CFRC-S were compar ed.
The CFRC specimens were prepared by the following process. A mortar layer of 1 mm in thickness was placed on the bottom of the mould first, and then unidirectional long sheaf-type CF previously impregnated with portland cement paste (reinforcement). Finally mortar was placed on the reinforcement, and then the CFRC specimens were cured in water.
The following factors were investigated on the mechanical properties of the CFRC specimens: (1) kinds of CF (PAN based HPCF and pitch based GPCF), (2) sand cement ratio (S/C), and (3) kinds of sand.
The CFRC-L (1.6 in S/C) prepared using HPCF or GPCF sheafs, exhabited the flexural strength of 18 MPa and 11 MPa, respectively. These values were 80-90% of that of CFRC-S's (1.6 in S/C).
The deflection of these CFRC-L's was nearly equal to that of CFRC-S's.
The specific strength of these CFRC-L's was over 20% larger than that of CFRC-S's.
Thus the mechanical properties of CFRC-L (1.6 in S/C) were nearly equal to those of CFRC-S. This reinforcing method is effective to lighten the specimen and for the application of CF.View full abstractDownload PDF (634K) -
1989 Volume 1989 Issue 137 Pages 104-114
Published: April 20, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1601K)
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