This paper presents the characteristics of Social Common Capital (SCC) and its role in the society of abundance. Also, it is explained why bamboo is regarded as the symbol of SCC. The society of abundance has three main characteristics. First, it should rest on the foundation of Institutionalism. Moreover, sustainable development without destruction of natural and cultural environments is required. Finally, the society of abundance should not only provide material richness, but also bring about the acceptance of ethical norms and affection toward natural and cultural environments. SCC is the social equipment sustaining the society of abundance. It can be said that bamboo might serve as an excellent example to exemplify how our society might attain sustainability and affluence, because bamboo is widely used for various ends such as the production of furniture or construction materials. Furthermore, bamboo is also important in relation to the formation of Japanese arts and literature.
Technical products introduced onto the market are more and more judged for more than a single quality. For example functionality is judged in relation to (lifetime-) cost, or in relation to mass, a measure for user friendliness or for environmental impact. This growing customer awareness to get more intrinsic qualities for money is causing a tremendous change in the development and design strategy of materials and structures, especially when applied in mass sensitive products, like transport vehicles in general and products which are being moved or carried permanently (machine parts, packaging and portable consumer goods). To identify a possible role for (bamboo) fibre-reinforced materials in mass sensitive products, the most trivial example, namely means of transport, is taken as subject to identify and to discuss the mass sensitive parameters which are determinant for the success of future transport systems (drag per unit weight and empty weight vs. payload) in a generic way. Finally the chances for bamboo fibres or better bamboo fibrils are brought into perspective to compete E-glass fibres in lightweight constructions, considering the specific mechanical performance in relation to the possible reinforcement morphology and to the available manufacturing techniques. The results are very surprising and promising for bamboo macro fibrils. Based on the available mechanical data, bamboo fibrils have the potential to surpass E-glass as a reinforcement for short fibre reinforced polymer composite structural elements like solid plates, shells and beams which are or dominated by or critical for buckling and bending.
Alkali treatment was performed on ‘Curaua' fibers to improve their mechanical properties. Curaua fibers were dipped into 5%, 10%, and 15% concentrated sodium hydroxide solutions for 1h and 2h. The effects of solution concentrations and treatment times on the physical and mechanical properties of curaua fibers were evaluated. Tensile tests of untreated and alkali treated curaua fibers were carried out. Those results showed that the tensile strength of the treated fibers decreased in comparison to untreated fibers, whereas the fracture strain of the treated fibers increased greatly in comparison with that of untreated fibers. In addition, green composites reinforced by untreated and alkali-treated curaua fibers were fabricated by a press forming method. Tensile tests were carried out for both composites. Results showed that both tensile strength and fracture strain of the composite using treated fibers increased in comparison with the composite using untreated fibers.
The use of graft copolymer of maleic anhydride polypropylene (MAPP) as a coupling agent in jute-polypropylene composites improved the mechanical properties of the composites. The scanning electron microscope (SEM) observations for fractured surfaces of unmodified and modified jute-polypropylene composites confirmed that the increase in performance was due to an increase of fiber-matrix adhesion. Jute and glass fibers were hybridized by ply-by-ply and skin-core structures, here glass and jute fibers were used as the skin and core layers, respectively. The test results show that the hybrid composites have superior mechanical properties. Especially, the impact strength increases significantly from 13.2kJ/m2 to 38.9kJ/m2, which is 190% higher than that of a jute fiber reinforced composite.
This paper describes a method to fabricate short bamboo fiber reinforced “green” composites (BFGC) and evaluate their mechanical properties. The composites were prepared by hot-pressing a mixture of starch-based resin and short bamboo fibers. Their tensile strength and flexural strength were characterized. The effects of fiber content and fiber length on the mechanical properties of BFGC were investigated in detail. Both tensile and flexural strengths of BFGC were strongly affected by fiber aspect ratio and fiber content. Bamboo fibers with a small aspect ratio of 20 do not act as reinforcement but as filler.
Fully biodegradable, environment-friendly ‘green' composites were fabricated using glutaraldehyde (GA) modified (MSPC-1) and GA and poly(vinyl alcohol) modified (MSPC-2) soy protein concentrate (SPC) resins. The SPC modifications resulted in better thermal and mechanical properties and lower moisture absorption due to the additional cross-linking provided by GA. Flax fabrics were used to reinforce MSPC-1 resin to produce composite sheets. Flax yarns were used to fabricate unidirectional composites using MSPC-2 resin. The fabric reinforced composites showed strength values of 50-55MPa and Young's modulus values around 1GPa. The yarn reinforced composites showed strength of over 125MPa and modulus values of about 2.25GPa in the longitudinal direction. These results indicate that green composites may be made with useful mechanical properties. The flax yarn reinforced composites may be used in secondary structural applications in automotive, housing and packaging whereas fabric reinforced composites may be used in packaging and indoor panels.
The interfacial shear strength (IFSS) between a bamboo fiber bundle and maleic anhydride polypropylene (MAPP) was examined for various kinds of surface treatments in conjunction with ultrasonic washing. Bamboo fiber bundles were extracted from Chinese bamboo by either mechanical scratching or steam explosion. The effect of fiber bundle diameter on IFSS was measured by using the micro-droplet test. The test results showed that higher IFSS was observed for bundles having smaller diameter. Isocyanate silane treatment improved IFSS in the case of raw bamboo fibers while it was less effective to improve IFSS for steam exploded fibers. The highest tensile strength of bamboo fiber reinforced polypropylene was obtained when steam exploded bamboo fibers were used as the reinforcement.
The purpose of this study is to examine a new method to obtain fine bamboo fibers (fiber bundles), which are used to reinforce thermoplastics instead of glass fibers. The tensile strength of FRTP was also examined using polypropylene as the matrix and bamboo fibers as the reinforcement. In this study, two types of bamboo fibers were used. One was mechanically extracted fiber (crushed fiber) while the other was steam explosion fiber. These fibers were frozen in a freezer or liquid nitrogen in order to decrease only their diameter. By freezing bamboo fibers, some soft cells sticking on the fiber surface were well removed, but we could not reduce fiber diameter due to freezing even at cryogenic temperature. It is found that a satisfactory tensile strength of FRTP using bamboo fibers can be achieved when fine bamboo fibers smaller than 120µm in diameter are used for injection molding.
Glass fiber/bamboo fiber hybrid BMC laminates were fabricated by compression molding, and their physico-mechanical properties were investigated. To improve their properties, many factors (constituent's ratio, process conditions, bamboo fiber content) were varied. The composite material reinforced with 25wt% hybrid fibers (25% bamboo and 75% glass fibers) showed better physico-mechanical properties (tensile strength: 37.0MPa, flexural strength: 140MPa, impact strength: 32kJ/m2) than other combinations.
Calculation of temperature field in a plane subjected to a pulsed heat input in the framework of non-Fourier heat conduction theory is investigated in this paper by using the finite element method. Comparison of temperature distribution predicted by the present model with the classical Fourier theory is carried out, and some discussions are made. The results reveal that a quite large difference between two approaches in the temperature distribution is observed and that a wavy pattern of heat propagation in the plane is detected through the non-Fourier simulation. The reflection of the heat wave at the edge of the plane is also observed in the non-Fourier simulation whereas no such reflection phenomenon appears in the classical Fourier heat conduction simulation.
In this work, numerical analyses are performed to study the behavior of stresses generated inside a kidney stone by direct pulse impingement during extracorporeal shock wave lithotripsy (ESWL), which leads to fragmentation of the stone. LS-DYNA, an explicit Finite Element code for non-linear dynamic analysis is employed to model the problems. Effects of pulse duration and acoustic property of the stone on stress field evolution inside the stone are studied for the pulse duration of 0.5 to 5.0µs and two acoustic impedances of actual kidney stones. The use of double shock wave sources to fragment the kidney stone is also considered in this paper. The effectiveness of this method for the kidney stone fragmentation is confirmed. Finally, the numerical analysis for the stone fragmentation is well compared with experimental results to confirm that the numerical analyses in this work provide reasonable results.
The present work presents methods to estimate elastic-plastic COD for circumferential through-wall cracked pipes for the Leak-Before-Break analysis of pressurized piping. Proposed methods are based not only on the GE/EPRI approach but also on the reference stress approach. For each approach, two different estimation schemes are given, one for the case when full stress-strain data are available, and the other for the case when only yield and ultimate tensile strengths are available. For the GE/EPRI approach, a robust way of determining the R-O parameters is proposed, not only for the case when detailed information on full stress-strain data are available but also for the case when only yield and ultimate tensile strengths are available. The COD estimates according to the GE/EPRI approach, using the R-O parameters determined from the proposed R-O fitting procedures, overall compare well with the published pipe test data. For the reference stress approach, the COD estimates according to the method based both on full stress-strain data and on limited tensile properties are in good agreement with pipe test data. In conclusion, experimental validation given in the present work provides sufficient confidence in the use of the proposed method to practical LBB analyses, even when information on material's tensile properties is limited.