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The objective of this paper is to predict the buckling pressure of a composite cylindrical shell using buckling formulas (ASME 2007, NASA SP 8007) and finite element analysis. The model in this study uses a stacking angle of [0/90]12t and USN 125 composite material. All specimens were made using a prepreg method. First, finite element analysis was conducted, and the results were verified through comparison with the hydrostatic pressure buckling experiment results. Second, the values obtained from the buckling formula and the buckling pressure values obtained from the finite element analysis were compared as the stacking angle was changed in increments from to . The linear and nonlinear results of the finite element analysis were consistent with the results of the experiment, with a safety factor of 0.85-1. Based on the above result, the ASME 2007 formula, a simplified version of the NASA SP-8007 formula, is regarded as a buckling formula that provides a reliable safety factor.

The main objective of this paper is to investigate the validity of the finite element method (FEM) on the buckling and post-buckling behavior of laminated composite cylindrical shells that have been subjected to an external hydrostatic pressure. In addition, a buckling pressure equation that is based on the ASME and American Bureau of Shipping (ABS) bucking equation and customized to USN125 composite material is also presented. In order to determine an application for composite material under external hydrostatic pressure, material tests were conducted for carbon–epoxy ply composite URN300 and USN125. The strength and stiffness of the fiber and resin of two composites were determined. Cylindrical panel tests were performed to investigate the behavior of post-buckling under vertical line load. Finite element analyses, using ABAQUS 6.6 code, have been performed, using a linear buckling model based on the solution of the eigenvalue problem, and a non-linear model based on the arc-length method for various cases. Furthermore, an external hydrostatic pressure test was conducted to verify numerical analysis. These results were compared with the previous results obtained by FEM on the buckling. Difference between FEM and the test result is expected to be approximately 18%.

A new method that optimizes a control of hydrocarbon (HC) addition to diesel exhaust gas for HC type DeNOx catalyst system has been developed. These catalysts are called the HC-DeHOx catalyst in this paper. The system using HC-DeNOx catalyst requires a resonable quantity of hydrocarbons addition in the inlet gas of the catalyst, because the HC concentration in a diesel engine is so low that the HC is not sufficient for NOx conversion. It is expected that this study offers a robust data developing HC injection system.

Wings for the defense industry such as fighters, missiles, and rockets should show no deformation or damage on the structure. The structures of existing wings had holes for weight reduction. The plates and frames were fixed with rivets or screws, which limited the weight reduction possible. In this study, an improvement was made in jointing methods through EB welding and laser welding. Welding strength was measured through tension testing. In addition, finite element analysis was performed for the welding process so as to deduce the optimum welding condition.

20 vol.% aluminum borate whisker (Al18B4O33w) reinforced AC4CH alloy composite was fabricated by squeeze casting method. The matrix is controlled its impurities, which make metal alloys, especially AC4CH alloy that is made by restraining 0.2% Iron and aluminum to make a matrix material. The perform of composite materials was made from Al18B4O33w with 5% regulated three kinds of inorganic binders, SiO2, Al2O3 and TiO2 sol, respectively and then sintered at 1373K. The composites were obtained by squeeze cast infiltration of the molten alloy to the perform. Then it was squeeze casting into the matrix. The status of adhesions of whisker perform was Observed by SEM. Micro-Vickers hardness and tensile properties at the room temperature were estimated. Al18B4O33w/ AC4CH composites containing TiO2 sol has excellent properties on tensile properties and microvickers hardness compared with the other composites without inorganic binder, containing SiO2 and Al2O3 sol inorganic binder.

The concept of a continuous lattice from the viewpoint of classical mechanics was introduced and a Lennard Jones 6 12 potential was used to modify the lattice fluid theory of Sanchez and Lacombe. Thus, a new equation of state for pure polymeric liquids was obtained. With this equation, PVT data, thermal expansivities and isothermal compressibilities of several polymeric liquids were calculated and compared with experimental values and with those of the lattice fluid theory and other theories. The new equation gave similar precision to Hole theory in the calculation of volumes thermal expansivity and isothermal compressibility and gave better agreement with the experimental data than the other theories used in the comparison.

It has been shown, using the significant structure theory of liquids, that a lower critical solution temperature behavior as well as a upper critical solution temperature behavior can be expected for polymer–polymer systems and that a phase diagram of closed-loop-type in a polymer–polymer–solvent system can be possible. In this article the sublimation energy of a mixture was expressed as a quadratic form of segment surface fractions on pure components rather than that of mole fractions, and the effect of the segment surface fractions on critical compositions was explained. The calculated partial miscibilities were in good agreement with the experiment.

The significant structure theory of liquids has been applied to the partially miscible systems, of which the temperature-composition phase diagrams are of closed loop type. In this paper, the sublimation energy of a mixture is expressed as a quadratic form of surface area fractions of components, and the energy correction parameter between one component and the other is assumed to be a second order function of temperature for simplicity, although it is a higher order function of temperatures and compositions. The calculated partial miscibilities are in good agreement with the experiment. Considered mixture systems are water-nicotine and waterβ picoline systems.