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Volume 25 (1999)
- Issue 6 Pages 211-
- Issue 5 Pages 171-
- Issue 4 Pages 131-
- Issue 3 Pages 87-
- Issue 2 Pages 45-
- Issue 1 Pages 1-
Volume 25, Issue 4
Displaying 1-4 of 4 articles from this issue
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Hiroshi AOYAMA, Hiroyuki WATANABE, Motoaki TERAI1999 Volume 25 Issue 4 Pages 131-139
Published: July 15, 1999
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSDownload PDF (8659K) -
Osamu MAJIMA, Hiroshi SUEMASU1999 Volume 25 Issue 4 Pages 140-148
Published: July 15, 1999
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSPropagation of multiple circular interlaminar delaminations in circular axi-symmetric plates subjected to a quasi-static transverse load, which is an idealized problem of damage accumulation in composite laminates due to low velocity impact loading, is numerically studied by a finite element analysis. A special fracture element is proposed for the analysis. The element, a nonlinear spring element, is characterized that the failure occurs at the stress equal to the maximum allowable stress of the material. The power form nonlinear property is defined so that the stored strain energy in the element becomes equal to the toughness of the material at moment of the failure. Then, both failures due to maximum stress and fracture mechanical instability are possible to be considered by using the element. Definitely, the failed surface must be presumed beforehand such as the case of delamination propagation in composite laminates when the present element is used. The element is applicable to the dynamic process accompanying damage accumulation, where the dissipated energy due to delamination propagation must be considered. The convergence of the solution with the element size is quite smooth and consistent with the theoretical results of fundamental problem of fracture mechanics. The propagation of the multiple delaminations in the circular laminate is well calculated.View full abstractDownload PDF (10238K) -
Yasuhiro TANABE, Takuji ISHIMOTO, Takashi AKATSU, Eiichi YASUDA1999 Volume 25 Issue 4 Pages 149-155
Published: July 15, 1999
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSCFRPs, reinforced with fibers having different modules/strain-to-breaks but a similar strength, were impacted by a 4 mm diameter steel sphere at a velocity of 900 m/s to 1, 800 m/s. Spall area and kinetic energy absorption of the sphere by CFRPs were investigated. In this velocity range, energy absorption ratio was independent with impact velocity in both CFRPs. A fiber cloth and a CFRP with low modules, i.e., high strain-to-breaks showed a high-energy absorption. Spall area increased with increasing specimen thickness. Tensile-stress applied areas simulated by a computer code also increased; The tendency of the experiments and simulation was quite similar. Most kinetic energy of spheres was absorbed at early stage of the impact.View full abstractDownload PDF (7208K) -
Shinji OKA1999 Volume 25 Issue 4 Pages 156-159
Published: July 15, 1999
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSDownload PDF (2346K)
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