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Volume 31 (2005)
- Issue 6 Pages 241-
- Issue 5 Pages 205-
- Issue 4 Pages 147-
- Issue 3 Pages 95-
- Issue 2 Pages 51-
- Issue 1 Pages 1-
Volume 31, Issue 4
Displaying 1-6 of 6 articles from this issue
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Tomonaga OKABE2005 Volume 31 Issue 4 Pages 147-159
Published: July 15, 2005
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSDownload PDF (9515K) -
Masato SEKISHIRO, Akira TODOROKI2005 Volume 31 Issue 4 Pages 160-167
Published: July 15, 2005
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSA stiffened composite panel is usually adopted for a structural component of an aircraft to avoid buckling. It is well known that stacking sequence optimizations are indispensable for the laminated composite structures. For the stiffened composite panel, they usually have more than two stacking sequences because they consist of a panel skin laminate and stiffener laminates. This causes that a couple of stacking sequences should be optimized together in the structural optimization of the stiffened composite panel. Authors have proposed a new stacking sequence optimization method called fractal branch and bound method for optimizing a single laminate. In the present study, the fractal branch and bound method is extended to optimize the multiple stacking sequences. The extended method is applied to obtain two optimal stacking sequences for a maximization of buckling load of a hat-stiffened composite panel. The improved method successfully provides two optimal stacking sequences determinately in a short time.View full abstractDownload PDF (6873K) -
Sachie URATA, Kazuo KUNOO, Nobuhide UDA, Kousei ONO, Tadashi NAGAYASU2005 Volume 31 Issue 4 Pages 168-176
Published: July 15, 2005
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSCarbon fiber reinforced polyimide resin composite is one of the promising candidate materials for high-speed civil transport (HSCT) that is expected to be developed in near future. In this research temperature dependence of mode-I interlaminar fracture toughness of carbon/polyimide composite has been investigated experimentally at temperatures ranging from 20°C to 200°C. Experiment was performed by way of double-cantilever-beam (DCB) tests. Crack length was measured continuously by the electric resistance method. At high temperature a large scale fiber bridging was observed. Those bridging fibers affect the measurement of crack-growth resistance curves significantly.View full abstractDownload PDF (5572K) -
Mitsugu TODO, Sangdae PARK, Kazuo ARAKAWA, Yasuharu TAKENOSHITA2005 Volume 31 Issue 4 Pages 177-183
Published: July 15, 2005
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSRecently, hydroxyapatite (HA) particle filled PLLA composite has been developed as a bioabsorbable bone fixation material to improve the bioactivity of the current PLLA implants used in oral and orthopedic surgeries. In this study, four kinds of HA fillers of different shape were used to fabricate HA/PLLA composites, and their fracture toughness values were evaluated. The result exhibited that the highest fracture toughness is induced by the micro-particle filler, while addition of the nano-particle filler to PLLA matrix leads to the lowest fracture toughness. Scanning electron micrography of the fracture surfaces showed that the highest fracture toughness of the microparticle filled composite is caused by debonding at the HA/PLLA interfaces and extensive local plastic deformation in the surroundings of the HA particles. On the contrary, the nano-particle filled composite having the lowest fracture toughness exhibits a flat smooth fracture surface, corresponding to low resistance to fracture.View full abstractDownload PDF (6484K) -
Koichi GODA, Junji OHGI, Jun-ichi TAMAOKI, Michiyuki SUZUKI2005 Volume 31 Issue 4 Pages 184-191
Published: July 15, 2005
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSA new finite element model for the damage analysis of fiber-reinforced ceramics matrix composites is proposed, in which the effect of the friction of interfacial sliding after debonding between the fiber and matrix are taken into account. It is assumed that three interfacial contact states, i.e. (1) interfacial bonding, (2) interfacial sliding, and (3) interfacial sliding with fiber breakage, exist in the composite during loading. Then, stiffness matrix of each interfacial contact state is newly formulated. It was found that the number of conditional unknown displacements was always equal to that of unknown loads. Therefore, the computation can be carried out without any change in size of the structure stiffness matrix. The calculated stress distribution was characterized by that the stress recovery region along a broken fiber is composed of two different stress distributions corresponding to the bonding and debonding regions. Monte-Carlo method was taken into the proposed finite element model, and stress-strain diagrams of a carbon-coated SiC fiber reinforced SiC matrix composite were predicted by superposition method. The results show that the average strength gradually decreases with an increase in the number of fibers; the coefficient of variation decreases. Finally, the simulated stress-strain diagram was compared with probabilistic models proposed by Phoenix-Raj and Goda et al.View full abstractDownload PDF (1022K) -
[in Japanese]2005 Volume 31 Issue 4 Pages 202
Published: July 15, 2005
Released on J-STAGE: August 11, 2009
JOURNAL FREE ACCESSDownload PDF (124K)
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