One technique of the control method for foams that have required internal structure was investigated, clarifying quantitatively effects of control factors on cell size and cell density and evaluating the characteristics of those factors. The following results were obtained. Equivalency is maintained between the foaming time and foaming temperature dependence of the cell density of foamed PC, and one master curve is obtained for the cell density. That is, the time-temperature equivalent law is held about cell density. Based on the time-temperature equivalent law, the control method, which can be predicted the required foaming conditions of plastics having arbitrary cell densities was proposed. Using above method, it is possible to predict the required foaming conditions of plastics having required cell densities.

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Tensile strength and creep behavior of a carbon.carbon composite (C/C) reinforced with a high modulus type PAN based carbon fiber (C/C (M40)) and a C/C reinforced with a low modulus type carbon fiber (C/C (T300)) were examined from room temperature to 2773 K in an inert atmosphere. Tensile strength of both C/Cs at the elevated temperatures enhanced up to 2273 K. Over 2273 K, tensile strength of the C/C (M40) continued to increase, on the other hand, tensile strength of C/C (T300) degraded. Tensile strength of C/C (T300) could not be obtained at 2773 K due to the decline of applied stress during tensile test by rapid creep deformation. Creep deformation appeared from 1873 K in both C/Cs regardless to the types of the reinforcing carbon fibers. No variation was found in the activation energy, however, C/C reinforced with a higher modulus carbon fiber exhibited lower stress exponent. The creep resistance of C/Cs could be enhanced by a carbon fiber processed at higher heat treatment temperature. The heat treatment of a C/C itself also enhanced creep resistance, however, its effect could not reach to that from the heat treatment of a carbon fiber.

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This paper presents temperature dependence of electric resistance and Joule heat properties in carbon fiber reinforced polyethersulphone (PES) resin composites. The composite specimens were fabricated using recycled CFRP pieces or carbon fibers mixed with PES resin through an injection molding method. First, resistivitytemperature curves of the composites specimens were measured during heat cycles. Next, temperature rise due to Joule heat was measured and plotted against input power. Finally, resistivity of carbon fiber was measured for temperatures up to 473 K. It is found that resistivity of the composites obeys the percolation power law and shows the negative temperature coefficient (NTC) in the temperature range lower than load-deflection temperature of the resin. This NTC is proved to be mainly due to the NTC of carbon fiber. Resistivity at room temperature is reduced after each heat cycle. Temperature rise due to Joule heat is approximately proportional to input power per unit volume.

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In order to evaluate the flexibility of matrix resin and hybridization of the carbon fiber with high compressive failure strain on the residual burst strength after impact, 6 types of FW-FRP composite pipes were tested. Impact tests with impactor radius of 20 mm were conducted on the specimens. Internal pressure tests were conducted on the specimen after impact tests. The burst strength of the virgin FW-CFRP composite pipes was decreased with decreasing Young's modulus of the matrix. The residual burst strength, however, increased with decreasing Young's modulus. The residual burst strength was also improved with carbon fibers with high compressive failure strain.

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In recent years, biodegradable plastics which have low effect on environment have been developed and attracted attention. However, many of them have lower mechanical properties than conventional engineering plastics. When considering their application as structural materials, reinforcing them with a natural fiber is one of the candidates of reinforcing method without a loss of their biodegradability. On such natural fiber reinforced biodegradable plastic composites, only some combinations of fibers and matrices have been tried and the mechanical properties of them are not well understood. In the present study, we use a bamboo fiber as the reinforcement and polybutylenesuccinate (PBS) as the matrix. We fabricate both a short fiber reinforced composite and long fiber unidirectional composites with different fiber volume fraction. We conduct tensile tests on these composites and evaluate the mechanical properties. In addition, we measure the bamboo fiber strength distribution. We discuss the experimentally-obtained composites properties based on the mechanical properties of the constituent materials.

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Polar amino groups of the waste silk sericin (SS) were modified by isocyanate compounds : 2- (methacryloyloxy)ethyl isocyanate (MOI) or 2-(acryloyloxy)ethyl isocyanate (AOI). By hot-pressing the MOImodified silk sericin (MOISS) or the AOI-modified silk serisin (AOISS), vinyl groups in the MOI or AOI were polymerized and the flexible and transparent films were obtained. Tensile moduli and strengths of the MOISS films were significantly enhanced as the MOI content increased. By the addition of the isocyanate compound, sericin films exhibited the lower solubility to the distilled water (80℃) and also the lower swell ratio to the distilled water (room temperature). For the enhancement of tensile properties and to restrain the water swelling, MOI was more effective than AOI. Biochemical oxygen demand (BOD) / theoretical oxygen demand (TOD) of the pure sericin film was almost 100% after 10days immersion into the activated sludge. By adding the isocyanate compound, BOD/TOD was decreased and delayed. When more than 50mol% of polar amino groups remained unreacted, sericin films retained the biodegradability. From the viewpoint of biodegradability, AOI was more effective than MOI.

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The work deals with the fabrication of long and short fiber reinforced ternary blends of epoxy resin, their morphology and mechanical properties. The ternary blends of epoxy resin based on diglycidyl ether of bisphenol A was modified with poly (ether sulfone) (PES) and poly (acrylonitrile-co-butadiene) rubber (NBR) and then cured with 4, 4-diaminodipheysulfone. For the reinforcement of the above ternary blends, long and short carbon fibers and aramid fiber were used. Morphology, bending properties and fracture toughness of these fiber reinforced ternary blends were evaluated. Short carbon fiber (CF) reinforced ternary blends of epoxy resin, PES and NBR was moulded by the solution method in which the fibers were mixed together with the solution of epoxy, PES and NBR in polar solvent and then cured. From the morphology observation, short CF reinforced ternary blends had two characteristic morphologies. One is the phase.inverted morphology in which the NBR-rich phase forms a continuous matrix, and the epoxy-rich phase forms particles. The other is a continuous domain of epoxy-rich phase contained CF. This continuous epoxy-rich domain grew larger with the slight increase of CF content. The bending properties and the fracture toughness of CF reinforced ternary blends were higher than unreinforced ternary blends, however the fracture behaviour changed from ductile to brittle behaviour at the content at the 6vol.% or more. Long carbon and aramid fiber reinforced ternary blends were moulded by the powder method in which the resin films manufactured from their powders of the solution of the ternary blends and the reinforcement fiber mats prepared using the “Fiber separating and flying machine ” were laminated by turns and compression moulded. The mechanical properties of the various long fibers reinforced ternary blends were higher than the short fiber ones.

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A new Prony series approximation technique which can determine the coefficients involved in relaxation function from data obtained by the Dynamic measurement analyzer(DMA) is developed. The proposed technique keeps positive value of every coefficient and satisfies smoothness of relaxation spectrum. In order to verify the effectiveness of the proposed technique, the authors measured the storage and loss modulus by DMA, then determined the coefficients of relaxation modulus function. As results, it is confirmed that the proposed technique can automatically predict and compensate lack of the experimental data in high reliability.

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Objective
The prediction of long-term fatigue life of various FRP laminates combined with resins, fibers and fabrics for marine use under temperature and water environments were performed by our developed accelerated testing methodology based on the time-temperature superposition principle (TTSP).
Approach
The base material of five kinds of FRP laminates employed in this study was plain fabric CFRP laminates T300 carbon fibers/vinylester (T300/VE). The first selection of FRP laminate to T300/VE was the combinations of different fabrics, that is flat yarn plain fabric T700 carbon fibers/vinylester (T700/VE-F) and multi-axial knitted T700 carbon fibers/vinylester (T700/VE-K) for marine use and the second selection of FRP laminates to T300/VE was the combinations with different fibers and matrix resin, that is plain fabric T300 carbon fibers/epoxy (T300/EP) and plain fabric E-glass fibers/vinylester (E-glass/VE). These five kinds of FRP laminates were prepared under three water absorption conditions of Dry, Wet and Wet+Dry after molding. The three-point bending constant strain rate (CSR) tests for these FRP laminates at three conditions of water absorption were carried out at various temperatures and strain rates. Furthermore, the three-point bending fatigue tests for these specimens were carried out at various temperatures and frequencies.
Achievements
The flexural CSR and fatigue strengths of these five kinds of FRP laminates strongly depend on water absorption as well as time and temperature. The mater curves of fatigue strength as well as CSR strength for these FRP laminates at three water absorption conditions are constructed by using the test data based on TTSP. It is possible to predict the long-term fatigue life for these FRP laminates under an arbitrary temperature and water absorption conditions by using the master curves.

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Objective
The damage tolerance performance of CFRP laminates for marine use was evaluated based on the clarification of impact damage and its propagation behavior. The damages within CFRP laminates were clarified with nondestructive methods and the direct observation of cross-section three-dimensionally.
Approach
The impact damage and its propagation behavior under fatigue loading and water environment of T300-3K plain woven and T700S-12K multi-axial knitted CFRP laminates were discussed. Matrix resin was vinylester, and the molding method was vacuum assisted resin transfer molding (VARTM). The damage mechanism within candidate CFRP laminates was evaluated based on the precise observation. Ultrasonic scanning was conducted as a non-destructive observation method, and the cross-sectional observation was also conducted at multiple sections of laminate. The difference between impact damage morphology of plain woven and multi-axial stitched CFRP laminates was characterized three-dimensionally.
Achievements
The damage tolerance performance of CFRP laminates for marine use was evaluated. For this purpose, the impact damage mechanism and its propagation behavior of T300 plain woven and T700 multi-axial knitted CFRP laminates were observed by non-destructive and destructive observation methods. Each image observed by these approaches was integrated and ‘three-dimensional’ damage distribution images were obtained. In addition, environmental effects on mechanical properties of damaged CFRP laminate were evaluated.

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1. Notes for Licensee
This MSRL-ONR database (version 1.0) (hereinafter “Database”) records the mechanical characteristics of the composites resulted from the ONR project named “Long-Term Durability and Damage Tolerance of Innovative Marine Composites (NICOP)” operated by the Materials System Research Laboratory, Kanazawa Institute of Technology (hereinafter“MSRL” or “Licensor”). It is requested that a user (hereinafter“Licensee”) uses Database only for the purpose of academic development or technological improvement. Please carefully read the terms and conditions of license below and agree to the same before the use. Please refrain from using Database if any item of the terms and conditions is disagreed. It is deemed that Licensee has fully agreed with the terms and conditions once Licensee starts to use Database.
2. Terms and Conditions
2.1 Copyright
Licensor holds and will continue to hold all the intellectual property including copyright, the right to use and the like, with regard to all the mechanical characteristics provided in Database.
2.2 Limitation of Use
If Licensee intends to use Database for business purposes, Licensee shall obtain a prior written consent by Licensor by contacting Mr. Masayuki NAKADA of MSRL (e-mail:nakada@neptune.kanazawa-it.ac.jp). If Licensee publishes the outcome in any sense obtained from the use of Database for purposes other than businesses, Licensee shall quote Database as a reference by inserting the wording “MSRL-ONR Database (Version 1.0), Materials System Vol.25 (2007), Materials System Research Laboratory, Kanazawa Institute of Technology, Japan.”. In any event, the copyright shall be retained by Licensor. If Licensee breaches any obligation under the terms and conditions, Licensor may limit or refuse the use of Database.
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LICENSOR DOES NOT WARRANT THE COMPLETENESS, ACCURACY OR USEFULNESS OF ANY ITEMS IN THE MECHANICAL CHARACTERISTICS OF DATABASE. IN NO EVENT WILL LICENSOR BE LIABLE FOR ANY LOSS OF OR DAMAGE TO REVENUES, PROFITS OR GOODWILL OR OTHER SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGE OF ANY KIND RESULTING FROM THE LICENSE GRANTED HEREUNDER.

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