Delamination is a predominant failure mechanism in composite structures. In the present study, double cantilever beam (DCB) tests were performed to investigate the effects of temperature and fiber orientation on the Mode I interlaminar fracture toughness, G_I, of carbon/epoxy composites, T800H/#3631. The values of G_I for three kinds of laminates, [0₁₂//0₁₂], [22.5/-22.5/0₈/-22.5/22.5//-22.5/22.5/0₈/22.5/-22.5] and [45/-45/0₈/-45/45//-45/45/0₈/45/-45], with a pre-cracked interface, that is // in each laminate, were obtained at various temperatures, i.e., -100°C, 20°C and 150°C. Fracture surface observation was also carried out by a scanning electron microscope (SEM) and optical microscope. It is shown that G_I is obviously affected by the temperature and fiber orientation. In the case of the specimen with delamination at 0//0, the fracture morphology changes as the delamination increases, but the value of fracture toughness for initiation G_IC (G_I at the crack initiation) is not so different from the one for propagation G_IR (G_I during the crack propagation), and the fracture toughness of the specimen with 0//0 interface is little affected by the temperature. However, G_IR of the specimen with 22.5//-22.5 interface shows a remarkable temperature dependence at a large crack length region. In case of the specimen with 45//-45 interface, G_IR is considerably affected by both failure mechanisms of crack jumping and fiber bridging, and the effect of temperature on G_IR is less than the case of the specimen with 22.5//-22.5 interface.

　　　The impact resistance improvement is important for glass members which are functional material in optics. It was reported that sticking a thin polymeric film on the glass plate is an effective way to easily reinforce the glass plates against impact loads. However, the reinforcing effect is not enough evaluated quantitatively. In this paper, impact fracture behavior was investigated with a glass plate stuck with thin polymeric film. An impact experiment was conducted using drop weight with a steel bar for the incidence of the impact load to a glass plate. In the experimental result of glass plate without film, stuck with film (3.2% thickness of the glass plate) and tempered glass plate, it was revealed the toughness for the fracture initiation was 12% improved by film sticking. Moreover, it was implied the fracture strength is not necessarily in proportion to the decrease of kinetic energy of the colliding object after fracture since it was largest with film stuck glass plate, nevertheless, the fracture strength was highest with a tempered glass plate. Furthermore, a proposal was made for the further improvement of the impact resistance by sticking thin film based on the investigation of the fracture mode of the glass plate.

　　　Our study demonstrates the ultrasonic system installed on the moving vehicle, which is capable to detect the conditions of road materials, i.e., to distinguish among dry, wet, icy and snowy surfaces. Initially, five kinds of road material were used to examine and verify the possibility of their detection by ultrasonic measurement during moving. The airborne ultrasonic wave (the central frequency of 40 kHz) propagates toward the specimen, and reflects at the interface of air and material surface due to the difference acoustic impedance as well as surface condition. The reflected ultrasonic wave is received by the ultrasonic transducer and recorded to the oscilloscope. The ultrasonic system was set on the hand cart and moved 10m with walking speed. Five kinds of road material were detected and characterized using the deviation of maximum amplitude of the ultrasonic wave.

　　　Experimental investigations were carried out to find out an efficient method of oxygen dissolution into water. Air injection through a single-hole nozzle was chosen in this model study because of its good handling performance and low running cost. First, basic three types were mentioned; bottom, top, and side gas injection into a cylindrical water bath. The air flow rate and the height of bubble dispersion region were kept constant. The dissolved oxygen was measured with a membrane electrode sensor. The history of dissolved oxygen concentration obeyed the first order reaction law. The dissolution efficiency therefore was evaluated in terms of the volumetric mass transfer coefficient. The side gas injection was found to be most effective among the three methods under the experimental conditions considered.

　　　The present study conducted the derivation of the empirical equation in terms of the heat transfer phenomena at the intake manifold of internal combustion engines and the implementation of its equation to 1-D engine simulation. The derived equation allows to calculate the Nusselt number at the intake system, which causes to predict the mass flow rate of intake air into the cylinder accurately, ultimately improving the fuel consumption by controlling the auto-ignition timing. The empirical equation was developed based on the Colburn equation, taking into consideration of the effects of the thermal boundary layer development and the intermittent air flow induced by the opening and closing of intake valves. Compared with the experimental data, the average errors of the Colburn equation and the empirical equation were estimated to be 91.1% and 2.7%, which gives to improve the prediction accuracy of the Nusselt number by deriving the empirical equation. The equation was then implemented in 1-D engine simulation and compared to the results of the Colburn equation, revealing the maximum and average intake air temperature differences of 11.4 K and 2.7 K, respectively.

Evaluation of the back pressure on a lateral wall of square cross section snow compression pressure vessel during snow compression was performed using a 12 multipoint pressure sensor. First, results of experiments and FEM analyses were used to evaluate elastic deformation of snow compression pressure vessel under water proof test condition to confirm the FEM integrity as a digital manufacture design tool. Results confirmed that the elastic deformation FEM analysis is sufficient to predict high-pressure vessel deformation during service. The strain rate ἐ was 4.00 × 10^-3 s^-1 － 1.70 × 10^-2 s^-1. Compression tests were conducted to evaluate back pressure distributions for obtaining important data to support safe usage of the pressure vessel. Results show that the back pressure occurs only around the bottom of the pressure vessel during compression. The maximum back pressure was p_b = 3.6 MPa at axial formation pressure p_z = 3.0 MPa. Furthermore, the maximum pressure reached almost 120% of the axial formation pressure.