Multiphysical course-grained simulators for molecular scale to meso-scale ionic fluids dynamics of soft materials are under construction. First, Monte Carlo Brownian Dynamics simulations are used to calculate equilibrium structures of polyelectrolytes brush-grafted on planes. The effect of added salts and the charge density parameters of polyions are studied. Then, the solvent model is made to include the solvation effect of polymers and counter-, and co-ions. In the framework of dissipative particle dynamics, polarizability of a set of solvent molecules is described as oscillators. The solvent flows are then included by calculating the Brownian particles by Langevin dynamics and the solvent flows by the Lattice Boltzmann method. In this method, the dynamics of a huge amount of small ions are enabled by treating each Brownian particle as a point described by a Stokes-source. These methods essentially treat ions as particles. In order to treat macroscopic phenomena, a multiphysical simulator based on continuum equations of ion distribution, solvent flow, and electric fields is created. Distributions of small ions are treated by Nernst-Planck equations to treat transitional and non-bulk ion distribution. These simulators can be used to analyze low friction mechanism of synovial joints, electrolytes dynamics of batteries, and so on.

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Liposomes produced from lipids have been studied as promising materials for a drug delivery system (DDS), since the liposomes are relatively non-toxic and biodegradable. For using liposomes as a drug carrier, the size of liposomes and the homogeneity in their structure are the most important characteristics. In this study, a novel technique of liposome production using a gas/liquid interface in a T-shape micro-duct has been suggested. By this method, the liposomes can be obtained without harmful organic solvents and the miniaturization of liposome production can be realized. The behaviors of gas columns and liquid columns in the micro-duct were changed depending on flow rate. Diameters of the liposomes were decreased by increase of the flow rate. The diameters of liposomes seemed to be affected by the length of liquid columns. Thus, flow characteristics in a liquid column were also analyzed.

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In studies of dispersion, dispersed particles migrate in accordance with the external flows. In this talk, we discuss lateral migrations of particles, whose migration direction is perpendicular to the main flow. In 2D simulations of binary dispersed suspension of large and small fluid droplets in a channel flow, it is found that the large droplets move to the center of channel and the small ones move to the vicinity of the walls when the surface tensions of the large and small droplets are the same. This phenomenon corresponds to the so-called margination. On the other hand, the large droplets move to the wall when the surface tension of large droplets is higher than the tension of the small ones. These results are related to the dynamics of blood, which is mainly composed of platelets, leucocytes and red blood cells. The platelets are smaller and stiffer than the red blood cells and the leucocytes are larger and stiffer than the red blood cells. The platelets and the leucocytes exist near the wall of the blood vessel. We expect an innovation of soft material for particle dispersion systems from the stand point of the lateral migration.

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In recent years, the need of soft food is increasing in step with the aging of the population. There are so few satisfying foods for the elderly to enjoy a meal. A printer capable of printing delicious food gives the elderly a big dream and is promising. In this study, we aim at the development of a 3D edible gel printer in order to make tasty soft food. We made a prototype of the 3D edible gel printer. The printer consists of syringe pump and dispenser. The syringe pump extrudes the solution, dispenser allowing for three-dimensional modeling. We succeeded in making the gels and plate-shape gel using the 3D edible gel printer.

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Materials that can repair cracks and recover from mechanical failure are desirable for a number of applications, because remendable materials both repair and prevent the propagation of cracks on the micro scale. The remendable materials offer the potential for increased durability, safety, and cost efficiency. This work is focused on remendable gels that contain thermoreversible bonds formed through the Diels-Alder (DA) reactionof furan (a diene) and maleimide (a dienophile). The DA reaction requires very little energy to create a DA adduct. At room temperature, furan and maleimide will react to form a DA adduct. Above 60℃, these bonds begin to break apart, and by 100℃, all DA adducts have been cleaved and furan and maleimide are recovered completely. The DA reversible bonds act as crosslinking points for thermo-healing of gels, naturally, gels will have thermoplastic property, and become recyclable and reusable. The prepared self-healable gel is named Switching-Knot (SK) gel.

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Self-healing fiber-reinforced ceramics (shFRCs) are widely expected to be advanced structural materials for aerospace engineering. The most attractive feature of shFRC is ultra-high reliability and life time induced by self-healing during service. However, there has still been lack of evaluation methodology on design stress, which is necessary to be put to practical use as structural materials, because the self-healing occurs under completion to the crack propagation induced by service stress. The present study aims to establish the experimental method to clear the completion between crack self-healing and crack propagation. Furthermore, the maximum stress under which the composite can safely self-healing (Limit load stress) was defined as the design stress of self-healing materials. Actually the limit load stress of alumina fiber reinforced self-healing alumina containing SiC interlayer as healing agent, which is typical shFRC, was investigated at 1100 ℃ in the present study. The experimental set up revealed that the sfFRC can heal under the stress of 80 % of cracked strength, under which the considerable crack propagation occurs without self-healing (the competition at room temperature). Therefore, limit load stress of shFRC at 1100℃ was succeeded to be determined to be 80 MPa.

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An advanced self-healing polymer composite with shape recovery function was proposed. The composite consists of continuous aramid fiber having thermal contraction ability and epoxy resin in which, microencapsulated dicyclopentadiene (DCPD) as healing agent and Grubbs catalyst are dispersed. The thermal contraction of the fiber with self-healing reaction heat allows the polymer composite to shape-recovery and to close crack. In this study, the exothermic behavior of self-healing reaction by DCPD was investigated and the effect of shape-recovery on exothermal behavior was discussed. The polymerization reaction heat of DCPD with Grubbs catalyst was measured by isothermal calorimetry. For the polymerization, maximum reaction heat was about 800mW/g at surrounding temperature 60℃. While they were 800mW/g and 500mW/g with DCPD 1.1 mL and 0.2, 0.6mL, respectively at surrounding temperature 40℃. Using the result, the heat transfer of the composite was simulated by finite element analysis and it is found to exhibit a proportional relationship between branched crack length and thermal contraction with a fiber. Therefore, the crack length needed for shape-recovery can be expected. That is, it is suggested that the voluntary shape-recovery materials are allowed to design by controlling interlayer between fiber and matrix.

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Creation of repeatable healing function is one of the main topics in self-healing materials. As a solution of this problem, we proposed the introduction of micro-channels on the surface of microcapsules as self-healing medium. Here, the micro-channels must be opened by tensile stress induced by micro-cracks and the healing agent as core material of microcapsules will be repeatedly leaked from opened microcapsules. In this study, the method to apply channels to microcapsules was investigated utilizing the removal of secondary phase in membrane. Here, magnetic particles and biodegradable resin were used as secondary phase. Magnetic particles treaded with release agent could be removed from membrane of microcapsules. In addition, core material could be repeatedly leaked through the hole generated by removal of magnetic particles by applying compressive force to microcapsule. The generation of hole could not be successful by hydrolysis of biodegradable rest as secondary phase. However, biodegradable resin weaken by hydrolysis could be broken by applying compressive force to microcapsule, resulting in repeated leakage of core material. These results indicate that the removal of secondary phase is one of sufficient methods to apply channels to microcapsules for self-healing materials.

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There is a potentially hazardous finishing process in which hydrofluoric acid is used to etch glass surface 10-100 μm depth to increase residual stress hence bending properties. However, the environmentally-friendly process of water treatment (WT) on the flexural strength (σ_b) and its bending strain (ε_b) of ultra-thin soda glass was studied. Water treatment mostly improved the σ_b and ε_b by the annihilation of residual stress at surface in the soda glass. On the other hand, the electron beam irradiation (EBI) mostly improved the σ_b and ε_b by the generaton of residual compressive stress probably occurring in front of crack tips in the soda glass. WT for short period gets the dull of the sharp tips of Griffith crack, whereas small dose of EBI cut the chemical bonds and generated dangling bonds at terminated atoms with both repulsive force and stress relaxation. Thus, enhancements of bending strength of glass treated by both WT and/or EBI can be explained. The enhancement of the final process of both WT and/or EBI can often improved the yielding ratio in industrial production process, the large cost reduction can be expected.

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Low-energy electron beam (EB) irradiation is a successful surface treatment. It generally enhanced stiffness and wear resistance of polymer utilized for common industrial articles. The EB irradiation induced strengthening of impact test was found for acrylic acid resin as well as silicate glasses. When EB irradiation generates dangling bonds at the weaker-bonded metal-oxygen atomic pairs in the nano-scale glassy structure, partial relaxation occurs at points of residual strain in the network structure, resulting in improvement of Charpy impact value of acrylic acid resin as well as silicate glasses. Furthermore, the EB irradiation induced hardening was also found for crystalline chromium plating sheets at surface. Since EB irradiation generates lattice defects of including point defect, stacking faults and sessile and mobile dislocations in crystalline metals. Since the defects disordered the crystal lattice perfection, it is difficult to move the mobile dislocations at surface region, resulting in enhancement of Vickers' hardness at small load of metals.

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Fluororesin, which exhibits high wear resistance as well as high strength and fracture toughness, can be applied to artificial blood vessel. However, the fluororesin is difficult to glue. To laminate the fluororesin and different polymers of polydimethylsiloxane (PDMS) and polyethylene (PE), the new treatment of hot-press after homogeneous low voltage electron beam irradiation (HLEBI) was innovated without glue. The adhesive force (^oF_p) of peeling resistance of laminated sheets of fluororesin and different polymers of PDMS and PE was evaluated. In order to evaluate the influence of the hot- pressing after HLEBI on ^oF_p, electron spin resonance (ESR) signals related to dangling bonds were observed. When HLEBI cut the chemical bonds and generated dangling bonds with nonbonding electrons at terminated atoms in monomers of fluororesin, PDMS and PE, the nonbonding electrons induced not only the intermolecular attractive force but also chemical bonding. Therefore, the hot- pressing after HLEBI was a useful tool for quick lamination of fluororesin and different polymers of PDMS and PE without glue.

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Acrylonitrile butadiene styrene (ABS) resin has been applied as light and inexpensive materials. In order to reduce the cost, the ABS resin covered with high strength CFRP sheets (CFRP/ABS/CFRP) has been proposed. Concequently, small dose of homogeneous 100 keV class EB-irradiation perfectly improved the a_<uc> of CFRP. The maximum a_<uc> value at mid P_f (0.50) for the CFRP/ABS/CFRP is approximately equal to or less than that for CFRP. Therefore, the maximum a_<uc> value at mid P_f (0.50) after 0.30MGy irradiation for the CFRP/ABS/CFRP was approximately equal to that for CFRP. It was also about 21.4% higher than that of these CFRP before treatment. The use of ABS resin as the core reduced other mechanical properties of tensile and bending, whereas the price of CFRP was apparently higher than that of ABS resin. Thus, it is possible that the sandwich structural composites of CFRP/ABS/CFRP could be utilized for daily articles.

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A new method with extremely large friction force by broad interface of carbon fiber (CF : 6μm diameter) coated by nickel (Ni) to prevent TiC formation and to enhance the ability of fiber rapping by molten Ti have been suggested for a joint (Ti/NiCF/CFRP) of carbon fiber reinforced epoxy polymer (CFRP) and titanium (Ti). The new joint part was strengthened by impregnated nickel-coated carbon fiber (NiCF) exhibited the high Charpy impact value (a_<uc>). Results showed overall, the Ti/NiCF/CFRP had higher a_<uc> than the Ti/Glue/Epoxy and Ti/Epoxy at each fracture probability (Pf). Based on the SEM and XRD pattern results, the chemical compound of TiC has not been observed in the Ti/NiCF/CFRP sample. Therefore, we concludes that the Ni coating prevents the formation of TiC in the of the Ti/NiCF/CFRP joint sample. Since molten titanium does not bite the carbon fiber, the Ni coated carbon fiber exhibits to maintain the high strength.

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Carbon fiber reinforced polymer (CFRP) and light metals are typical light structural materials with high specific strength to save their energy and to enhance the mobility of airplane. In order to prevent the fracture at joint interface, a joining method using impregnated nickel (Ni)-coated bundles of carbon fiber (CF) with:6 μm-diamete had been successfully developed in joining between CFRP and light metals. The joint with strong interfacial friction force of fiber and matrix enhanced the tensile strength and Charpy impact value of light metals/CFRP. Increasing the volume fraction of carbon fibers up to 7 vol% always enhanced both tensil fracture strength and Charpy impact value. Both values became to be satulation at more than 10 vol% carbon fibers. The Ni coating improved the contact condition between carbon fibers and molten aluminum, resulting making composite very well. In addition, it prevent to form the great amount of aluminum carbites, resulting in getting strong light metal/CFRP joint reinforced by carbon fibers.

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Energy harvesting is expected to use for collecting small and/or thin dispersed energy sources wasted in our daily life. A vibration generator, in this study, can convert the vibration energy such as noise and mechanical fluctuation behavior of the structures into electrical energy. Our group has been paying attention to the magnetostrictive vibration power generation using new Fe_based magnetostrictive alloys. The principle of the electrical generator is based on the inverse magnetostrictive effect by using the leakages of magnetic flux from the magnetostrictive oscillating object surrounded by the coil. Most large power is obtained at the resonance frequency point and it seems very important to develop the modified device fitting to wide-band spectrum of structure.

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In this study, authors presented the feasibility study of the magnetostrictive vibration energy harvester under the low intensity excitation condition, 0.71[mm/s] (RMS). The experimentally obtained power generation performance of the vibration energy harvester was quite low comparing with the previous authors' studies about the piezocomposite vibration energy harvester.

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The miniaturization of GPS buoys is important for reducing tsunami hazard because a lot of them enable to observe marine phenomenon swiftly. A smart structure is effective for making vibration powered generator small without performance degradation. However the resonance type cannot generate enough electricity when input frequency is different form resonant one. The downsizing of them requires to reduce buoy weight and increase buoyancy. The increase in decay constant of the generator is also effective realistically. This policy to improve the generator is serviceable for the device with piezoelectric element. To increase rigidity of the beam and decay constant of piezoelectric element contributes to improve the generator.

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This paper describes the new engineering "Disaster Mitigation and Sustainable Engineering" where the "Smart Materials and Structural Systems" field can be effectively applied. A couple of examples such as a smart material and structural system based on honeycomb like active laminates to be used against Tsunami, which has been investigated by the authors and many others, are also introduced in this paper and discussed.

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In this study, porous aluminum core filled in hollow thin-walled steel pipe composite materials (porous core pipe) was fabricated by applying friction welding. Precursor of ADC12 porous A1 was fabricated by adding blowing agent powder into ADC 12 plates by means of applying friction stir processing. The precursor was put into the hollow thin-walled steel pipe, and the rotating tool was pressed into the precursor. Friction heat was generated and ADC12 precursor / SUS304 thin-walled steel pipe composite materials were fabricated by friction welding. Porous core pipe with metal bonding was successfully fabricated by heating the precursor. The compression properties and deformation behavior of porous core pipe was obtained by the compression test. As a result, deformation behavior of porous core pipe was different from the hollow pipe and compressive stress of porous core pipe increased compare with the hollow thin-walled steel pipe and ADC 12 porous Al.

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Porous aluminum is a lightweight material with high energy absorption properties. In this study, impact test of A1050-ADC12 functionally graded porous aluminum fabricated by friction stir processing (FSP) route was carried out. It was shown that deformation began from low strength A1050 layer. This result is consistence with result of static compression test of A1050-ADC 12 functionally graded porous aluminum.

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Porous aluminum is a lightweight material with high energy absorption properties. In this study, porous aluminum core sandwich panel consisting of ADC 12 porous aluminum and dense ADC6 plates was fabricated by friction stir processing (FSP) route. In the FSP route, both fabricating ADC12 precursor and bonding the ADC12 precursor to dense ADC6 plate can be conducted simultaneously. It was shown that fabricated sandwich panel has good bonding between ADC 12 porous aluminum and dense ADC6 plates. Also, lightweight sandwich panel, which has porous aluminium core with porosity of higher than 70 %, can be successfully obtained.

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Porous aluminum (porous Al) is a multifunctional material with lightweight and high energy absorption properties. Functionally graded (FG) porous Al is fabricated by combining different pore structures and Al alloy. In this study, pure Al(A1050)/Al-Mg-Si(A6061)/Al-Si-Cu(ADC12) FG porous Al of three layer structure was fabricated by friction stir welding route. Pore structures of A1050-A6061-ADC12 FG porous Al was observed nondestructively by X-ray computed tomography inspection. The compression properties and deformation behavior of A1050-A6061-ADC12 FG porous Al was obtained by compression test. It was shown that the fabricated A1050-A6061-ADC12 FG porous Al compressive test specimen had potential to exhibit three different deformation stages and three plateau regions corresponding to the uniform porous Al with A1050, A6061 and ADC 12.

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Microstructural evolution of Al-Al_3Ti multi-phase material by equal-channel-angular pressing (ECAP) is 3-dimenstionally investigated. The Al-Al3Ti multi-phase materials have Al_3Ti platelet particles in Al matrix. Especially, the distribution changes of the Al3Ti particles with ECAP are focused in this study. The Al_3Ti platelet particles are fragmented by ECAP under all of processing routes. When the Al-Al_3Ti specimen is deformed by ECAP under route A, the fine Al3Ti particles are homogeneously distributed along to deformation axis and the plane normal of the Al_3Ti particles are aligned perpendicular to deformation axis. On the other hand, the Al_3Ti particles in the specimens deformed under route Bc and route C are gathered and form several groups. Moreover, orientation distribution of the Al_3Ti particles in the specimen deformed under route Bc is random, and the Al_3Ti particles in the ECAPed sample under route C are aligned. The differences of the Al_3Ti particle distribution depending on the processing routes comes from shear deformation mechanism and plastic flow of the A1 matrix. Furthermore, it is found that fragmentation of the Al_3Ti particles by ECAP are preferentially occurred on (112)_<A13Ti>.

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It is known that the equilibrium shape of Al3Ti particles in Al_3Ti grain refiner is platelet, and the aspect ratio of Al_3Ti platelet in Al-5mass%Ti alloy grain refiner is reported to be 13. Therefore, average disregistry value for the platelet shaped Al_3Ti can be estimated to be 4.78%. On the other hand, the average disregistry value for the granular shaped Al_3Ti is 2.99%, which is much smaller than that for platelet shaped Al_3Ti. In this study, Al/granular shaped Ti particles sintered compact is fabricated by spark plasma sintering (SPS) method. Since granular shaped Al_3Ti particles can formed by the reaction, 3A1 + Ti -> Al_3Ti, the fabricated Al/granular shaped Ti particles sintered compact can act as a better grain refiner.

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Diamond-particle-dispersed-aluminum (Al) matrix composites were fabricated in solid-liquid co-existent state by Spark Plasma Sintering (SPS) process from the mixture of diamond powders, Al powders and Al-5mass%Si powders. As the diamond powders, two kind of powders, monomodal diamond powders of 310μm in diameter and a bimodal diamond powder mixture of 310μm and 34.8μm in diameter, were used. The microstructures and thermal conductivities of the composites fabricated were examined. These composites were all well consolidated by heating at a temperature range between 798K and 876K for 1.56ks during SPS process. No reaction at the interface between the diamond particle and the Al matrix was observed by scanning electron microscopy for the composites fabricated under the sintering conditions employed in the present study. Although the relative packing density of the monomodal composite decreased from 99.1% to 87.4% with increasing the diamond volume fraction in a diamond volume fraction range between 50% and 60%, that of the bimodal composite was higher than 99% in a diamond volume fraction range up to 65%. The thermal conductivity of the bimodal composite was 455-581W/mK, which is higher than that of the monomodal composite in a diamond volume fraction range higher than 60%, and it is 530-58 lW/mK in a diamond volume fraction range between 60 and 70vol.%. -

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The martensitic and the reverse transformation temperatures are directly related to the bending rigidity of the TiNi shape memory alloy (SMA) wire. In this paper, aiming at obtaining a functionally graded TiNi shape memory alloy wire that varies in bending rigidity from high to low along the wire axis, a new fabrication process of combined powder metallurgy and plastic working is proposed. First, a multi-layered TiNi green compact, where Ti-Ni compositions varied layer by layer, was sintered by means of spark plasma sintering process, and then it was hot-extruded into a wire. In this paper, we investigated functionally graded properties of deformation properties of the extruded wires. According to tensile test, it is found that the wire having both shape memory effect and superelasticity was successfully fabricated because functionally graded properties of transformation temperatures still retain even in the hot-extruded wire.

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In this research, the fabrication conditions of Ni-rich Ti-55at%Ni alloy by pulse-current sintering and the shape memory properties of the sintered alloy were investigated experimentally. The sintering was performed at various temperatures in a vacuum, and then the solution treatment was carried out at various temperatures in Ar gas atmosphere. Finally the aging treatment was performed to improve the shape memory properties of the alloy. As a result, the optimum sintering and solution treatment conditions could be obtained. It was also found that the alloy shows shape memory properties by performing aging treatment and the deformation resistance and recovery strain depend on the microstructure of the aged alloy.

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The purpose of present study is to investigate the effect of heat treatment conditions on mechanical properties of Cu-Al-Mn shape memory alloy. The Cu-17mol%Al-l lmol%Mn wire with a 1.8mm in diameter is used. The heat treatment condition is 900℃ for 10 minute and then aged 100℃ for 15 minute (1 time or 2 times). The transformation temperatures were measured by differential scanning calorimetly (DSC). The mechanical properties were measured by tensile machine at 25℃. The property of bending fatigue life is measured by bending fatigue tester. The results in present study are as follows: (1) Both aging condition specimens were shown super elasticity. (2) The average of fatigue life is about 3000 times at 2% strain (gained 1 time) and about 5000 times (aged 2 times), respectively.

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The creep and creep recovery behavior under the stress-controlled subloop loading in TiNi SMA tape were investigated. The results obtained can be summarized as follows. (1) If stress is kept constant at the upper stress plateau after loading up to the stress-holding start strain under a constant stress rate, creep deformation occurs due to the spread of the SIMT process. (2) If stress is kept constant at the lower stress plateau after unloading down to the stress-holding start strain from the maximum strain under a constant stress rate, creep recovery deformation occurs due to the reverse transformation. (3) If the stress-holding start strain is large, the creep strain rate under constant stress is high and the maximum strain is large. The creep strain rate increases based on temperature increase due to the exothermic SIMT up to the stress-holding start strain.

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The SMC belt composed of two kinds of SMAs with different phase transformation temperatures and SMP was fabricated and the three-way (reciprocating) movement and recovery force in bending actuation were investigated. The results obtained can be summarized as follows. (1) The three-way bending movement was achived during heating and cooling based on the characteristics of the SMA tapes and the SMP tape. (2) The recovery force decreased at first and increased thereafter during heating and decreased during cooling. (3) The development and application of multi-functional SMCs with simple structure for three-dimensional actuators are highly expected.

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In this study, shape memory alloy (SMA) wires which were thermally-treated in a desired shape were embedded in the unidirectional carbon fiber reinforced thermoplastic (CFRTP) laminates aiming to utilize actively the anisotropic property of CFRTP as the active thermal actuator. The deformation behavior of the SMA/CFRTP laminate subjected to thermal load was investigated. The temperature is a significant parameter because the elastic property of SMA/CFRTP depends on the shape memory temperature of SMA wires and glass transition temperature of thermoplastic matrix. In this experiment, SMA/CFRTP laminates were fabricated with a hot press molding using unidirectional carbon fiber /PA6 (CF/PA6) prepreg sheets, PA6 films and Ni-Ti wires. The effects of placements of SMA wires and laminated sequences of SMA/CFRTP laminates on the deformation behavior of these laminates under the elevated temperature were investigated with the digital 3D strain field measurement.

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As represented by Miura-ori, origami has inspired various types of deployable structures. Usually, these Origami structures are designed under the assumption of "rigid folding", which means each plane is undeformable and connected with ideal joints. The authors proposed a new strategy for designing deployable structures by using partially elastic origami models. These new origami structures take into account the elastic deformation. It enables us to estimate the elastic energy through folding and unfolding process and to design self-deploying origami structures. This paper presents the manufacturing methods for the deployable structures based on partially elastic origami. The challenge is summarized in two main problems: treating of plate thickness and designing for hinge parts. Firstly, the authors propose the method using commercially available hinges and make the sample of aluminum alloy plate. Secondly, by using 3D printer, some plastic samples are made and the representative one is shown. Finally, the deformations of elastic parts in these trial models are compared with a theoretical model.

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This paper describes improvement of the active laminate in bonding strength by using the oxide film of aluminum for insulation. Conventional types of the active laminates were made by hot pressing of an aluminum plate as high coefficient of thermal expansion (CTE) material, a unidirectional carbon fiber reinforced plastics (CFRP) prepreg as low CTE and electric resistance heater, and a unidirectional glass fiber reinforced plastics (GFRP) prepreg as low CTE and insulating material. However, the insulating layer reduces actuation capability of the active laminates. Therefore a two-layer type active laminate was made by using anodized aluminum plate as high CTE and insulator material instead of using GFRP. In this study, the effect of oxide film thickness of the aluminum plate on the bonding strength between the aluminum plate and the CFRP of the two-layer type active laminate was investigated. In addition, bonding strength improvement by irradiating the layer or layers of the active laminates with electron beam (EB) was tried. The main results obtained are as follows: (1) Bonding strength between the aluminum and the CFRP layers of the active laminates and fraction energy can be improved by anodizing the aluminum plate. (2) The fracture energy was improved by EB irradiation.

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Smart space structure systems which measure and correct their shape on orbit have been studied as a future high-precision space structure systems. Piezoelectric ceramics are often used as an actuator in the system. To correct and retain the shape of the structure, electric voltage must be applied continuously. To reduce the amount of electricity usage, a new control method was proposed, where a fact that strain remains after a pulsed voltage input due to the hysteresis in strain-electrcic curve of the piezoelectric actuators was utilized effectively. In this paper, feasibility of the proposed method was verified for a piezoelectric ceramic plate and a beam on which the piezoelectric ceramic plate was bonded. The result showed that the strain of the piezoelectric ceramic plate and the tip displacement of the beam remained after the pulse. Although the beam vibrated after the pulse, the vibration was suppressed by applying a feedback control or controlling the shape of the applied pulse input.

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An estimation method of the piezoelectric constants of thin films bonded on one surface of the beam was investigated. At first, theoretical analysis was carried out and equations of motion of the beam and sensor output equations were derived. Then, forced vibration responses of the beam are calculated under the condition that the system is harmonically excited. Piezoelectric d_<31> constants were estimated from the displacement response of the beam and the output voltages of the piezoelectric films.

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This paper proposes a frequency tuning method of the piezoelectric sound absorbing panel. The piezoelectric elements on the panel shunted with an inductance and a resistance work like a dynamic vibration absorber. The sound absorbing panel transforms sound energy into the vibration energy, and this vibration energy is dissipated through the resistance using electrical resonance. Because the piezoelectric sound absorbing panel has high sound absorption coefficient around its natural frequency, this method can be used for low-frequency noise reduction. However, the frequency at which the sound absorption coefficient becomes 1 was automatically determined in the method proposed in the previous research. Therefore, this paper proposes the frequency tuning method of the piezoelectric sound absorbing panel using the LR circuit. The governing equations were theoretically derived, and the optimum values of the LR circuit were formulated. Theoretical analysis was validated through simulations and experiments.

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This paper describes fabrication of a piezoelectric ceramic fiber/aluminum alloy composite using the Interphase Forming/Bonding(IF/B) method. A metal-core piezoelectric ceramic fiber is very fragile and reactive with molten aluminum, therefore general fabrication processes such as diffusion bonding and casting are hard to be applied. In this study, hot pressing condition was examined in order to embed the metal-core piezoelectric ceramic fiber without mechanical damage and loosing piezoelectricity to an aluminum alloy matrix instead of the pure aluminum matrix used in the previous studies. As the results, the proper hot pressing conditions such as temperature, pressure and period have been determined, and the piezoelectricity of the embedded fiber was confirmed by the measurement of P-E hysteresis loop. The proper hot pressing condition, that is, pressure and temperature are 2.2 MPa and 873 K, respectively enables to remove the coarse and fragile eutectic alloy phase from the composite.

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This paper describes the fabrication of the metal-core lead zirconate titanate (PZT) fiber/aluminum composite using the Interphase Forming/Bonding (IF/B) method in the air and its characterization. In the previous studies, in order to simplify the fabrication procedure and reduce their costs, the optical fiber/aluminum composites were fabricated using a compact hot-pressing equipment which enables rapid heating to reduce oxidation in the air as a model experiment. In this study, the metal-core PZT fiber/aluminum composite was fabricated in the air and piezoelectric property of the embedded fiber was confirmed by measuring its polarization-electric field (P-E) hysteresis loop. In addition, its characterization was investigated by an impact test. As the impact test, a steel ball was dropped on the composite and the output voltage from the composite was measured by an oscilloscope. The results obtained indicate that the output voltage is proportional to the square root of impact energy, and the output voltage depends on the impact directions.

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Health monitoring is an important issue especially for a structural system being in operation for a long time. In this study, we deal with an approach to damage identification of structural system by means of a multi-layered neural network. The approach is based on the change in some specific characteristics caused by the damage of the structural members. The relation between the damage and the characteristics is implemented with a multi-layered neural network; the error back-propagation with fixed connection weight is adopted to solve the inverse problem for the damage identification. We discuss the type of characteristics used for the damage identification. Numerical experiments with truss structures are conducted and the feasibility of the proposed approach is demonstrated.

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A new method for estimating the structural failure probability based on the directional importance sampling simulation combined with a numerical radial integration procedure to determine the conditional failure probability in the sampled direction is proposed. The standardized orthogonal space is divided with several concentric hyperspheres and the conditional failure probability in the sampled direction is evaluated by a radial piecewise integration of the failure probability volume contained in the respective concentric hyperspheres. Samples are generated from the importance sampling p.d.f.s centered at the design points on the respective limit state surfaces and directions from the origin to the respective sampled points are proposed to utilize as directional vector samples equivalently. Numerical examples show that the proposed method gives accurate estimations of the structural failure probability efficiently.

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So in this method, the regression coefficient is estimated as distribution. This approach considers distribution of the damage parameter. Thus probability of failure evaluation is possible. In addition, the Bayesian estimation is used. This is determined the distribution of the estimated value by against damage true. Further, to adapt to the individual is small sample of, by using the Bayes' theorem, the prior distribution and other individuals. Posterior distribution can be drawn by updating prior information using measurement data. This system is possible to evaluation at small sample, Low cost. When the maintenance is considered from the result of damage evaluation, damage evaluation is not the whole, to estimate a part carefully. So, we propose the "weighting". In this paper, one cases as the delamination identification problem of CFRP laminated plate. Object is the identification of damage in a small sample of large estimation error. Evaluation of the effect of the change of the regression coefficient distribution has on the output result. Influence of an estimated error is different to overestimation or underestimation of probability of failure. The weight function performed influence examination given to a risk value. We investigate relates effective weighting to reduce the risk.

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Composite materials have been widely used for primary structures of aircraft, and a rapid diagnosis method for large composite structures like aircraft components is required. In this study, a new inspection method using a lightning protection shield (LPS) as a load sensor and its wiring is proposed. The proposed sensor identifies the coordinates of the impact point by the touchpad techniques. To verify the practicability of the proposed sensor, impact load tests were conducted with the proposed sensor of 360mmx225mm. The impacted position was identified within an error of 10.3mm.

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The present paper studied feasibility of refractive-index fiber-optic sensors for measuring cure index and local concentration of CNT composites during molding. Epoxy resin and 0.1, 0.01, 0.00lwt% of CNT were used for manufacturing composites. After the resin was poured in a small mould with two refractive-index fiber-optic sensors, it was cured at 80 ℃. From the measured optical powers, variation of refractive index Δn of the composites was calculated. From the experimental results, it was found that the cure index curves for 0.001% specimen show the same curves, however the fluctuation remained in the cure index curves of 0.1% specimens. Therefore, this method can be used to measure cure index of CNT composites when the concentration of CNT is low. From the data, frequencies of fluctuation amplitude were calculated. It was found that the frequencies of fluctuation amplitude appeared linear against concentration of CNT in a log-log plot. Since the measurement area of the sensor has 10 micron meter diameter, this result showed that this sensor has feasibility of measuring local concentration of CNT.

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In the present study, we propose a system for monitoring cure process of FRP prepregs during hot-press molding using dual light sources, FBG sensors and refractive-index sensors. The optical system is composed of a 1310 nm narrow-band FP-LD light, a 1510nm broad-band SLD light, 1300/1500 WDM couplers, a spectrum recorder and an optical power meter. The FBG sensors have a distal end at which Fresnel's reflection between glass and resin occurs. The reflected 1310nm light form the distal end and the FBG reflection (about 1550nm) were divided into two individual paths by a WDM coupler. The power of 1310nm light was measured by an optical power meter and used for calculating refractive index of matrix resin. Spectra of the FBG light were recorded by a spectrum analyzer. In this study, GFRP prepregs were used for the experiments. From the results in the present paper, it was found that the our monitoring system could monitor not only strain and cure index but also voids generation and resin flow.

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This paper presents a new impact identification method using the high-speed strain measurement system. This system consists of fiber Bragg grating (FBG) sensors and an arrayed waveguide gratings (AWG) filter, and can detect large strain waves such as the impact strain waves. Firstly, we propose new algorism for calculation of coordinates of the impact-loaded point. Although conventional detection methods are carried out under the condition that the propagation speed of the elastic wave is given, this proposed method enables us to calculate the position of a wave source without its speed. This algorism also has the great versatility of sensors positions. Next, the high-speed strain measurement system used in this study is mentioned. Using multiplexed FBG sensors, this system can detect the strain wave on four different points at the same time. Finally, the impact identification tests are carried out on the carbon Fiber reinforced plastic (CFRP) laminate. The aforementioned algorism are used to calculate the impact loaded position from the difference for the arrival times of the four sensor points. The results indicate the correct position with relatively small errors.

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Tungsten-containing diamond-like carbon (W-DLC) coatings designed for the purpose of producing new strain sensor was fabricated by chemical vapor deposition and DC magnetron co-sputtering of a tungsten metal target. The electrical resistance was measured by four-terminal method and shown to be proportional to the value of compression and tensile strain. The expression ΔR/R=Kε was applied to the experimental results in order to determine the gauge factor of each coating. The W-DLC coating showed the performance equivalent to the commercial strain gauge.

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Fiber reinforced thermoplastic composites has poorer matrix resin impregnation to fiber reinforcement, because of extreme high viscosity of molten thermoplastics. Intermediate materials using Micro-Braiding technique have been developed to overcome these difficulties. In this study, composite textiles plates were fabricated under various fabrication conditions, and their impregnation were investigated experimentally and predicted by theoretical formulae. As a result, impregnation increased with molding pressure and time, and impregnation of single-ply textiles is improved compared with that of multi-ply textiles because they have more collapsed fiber bundles, hence closer impregnation distance. On another front, the analytical predictions were in disagreement with the experimental results.

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During Resin transfer molding (RTM) process for manufacturing composites, entrapped air may remain as void in a part to bring significant decrease of the mechanical properties. In the past, it has been presented that amount of the void formation depends on velocity of resin flow. However, in the case that an anisotropic fabric is applied, directions of the resin flow may also affect on the void formation. In this paper, the effect of anisotropy of fiber on void generation was examined analytically and experimentally. Finally, good agreement was obtained between results of them.

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This study aims to reveal the mechanism of electro-fusion joining of CFRTP composites using carbon fiber filament as resistance heating element. The material used is woven CF/PPS laminates. The effects of applied voltage, fusion time and thickness of inserted PPS films on fusion behavior of CFRTP composites in electro-fusion welding were investigated. The welding area and fusion shape were evaluated by microscopic observation and its image analysis. The experimental results revealed that electro-fusion behavior is influenced by thickness of inserted PPS films and electric resistivity of CFRTP laminates. From the welding area calculated by image analysis, it is obvious that the welding area of CFRTP laminates tends to increase with increasing the applied voltage and fusion time. It was also confirmed that woven CF/PPS laminates could be welded at low applied voltage and long times.

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This study describes the punching behavior of woven carbon fiber reinforced thermoplastic composites. The matrix polymer used is Polyamide 66 (PA66) resin. A circular hole is machined by two types of punch with different tool profiles such as flat edge and wave edge. Load applied at punch which was pushed to laminates with a small servo-pressing unit were measured. The quality of machining was examined by a digital microscope observation of cross-section near hole. It was found that the applied load reduced with increasing the temperature of specimen and working speed of punch. It was also recognized that wave edge tool became lower the applied load than flat edge one.

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