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 pb = 3.6 MPa at axial formation pressure pz = 3.0 MPa. Furthermore, the maximum pressure reached almost 120% of the axial formation pressure.
Spatial Distribution Characteristic of Transient Vibration Response on Thin Membrane including Wrinkles and Creases induced by Impact Loading Takashi IWASA and Hiroyuki TANAKA Spatial distribution characteristics of spectra measured at several points on a vibrating membrane surface are investigated. Three membrane models, which are square polyimide films with a flat surface, a wrinkled surface and a creased surface, are treated. An impact load is applied to the corner of the membranes, and a flexural wave propagation as well as a stationary vibration appearing on the membrane surfaces is measured by photogrammetry using a grating projection method. The results show that the vibration characteristics of the membrane surfaces, which are a flexural wave propagation, a natural frequency and a maximum amplitude of the response, are strongly affected by the surface features of the membranes, while the spatial distribution of the logarithmic magnitude of the spectra on the membrane surface has a similar distribution property regardless of the existence of wrinkles and creases.
A two-dimensional (2D) scanning moiré method was proposed to measure the micron/nano-scale deformation distributions in two dimensions using a single moiré pattern under a laser scanning microscope. The 2D scanning moiré pattern in a large view field (width is 500~2000 times the grating pitch) comes from the interference between a cross specimen grating and the 2D laser scanning dots which serve as the reference grating. The 2D scanning moiré fringes can be separated to two groups of parallel one-dimensional moiré fringes in two directions using complex Fourier transform. The full-field micron/nano-scale deformation distributions in the x and the y directions are measureable from the corresponding parallel moiré fringes, respectively. Consequently, the 2D displacement and strain distributions can be determined using a single 2D moiré pattern, instead of two moiré patterns in two directions. The proposed method possesses the advantages of time saving, large view field, non-destruction, and high accuracy for two-dimensional deformation measurement of various materials evaluation.
Japanese sword is Japanese historical famous weapon since ancient times, and has perfectly characteristics as the sharply, strongly influenced by the deformation and broken. Furthermore, the Japanese sword has also an affective characteristics as the traditional crafts, which recognized by the warlords. While the affective shape and historical consideration of Japanese sword is one of the most important variables for evaluating the new generation sword by the modern swordsmith, the Japanese sword have been generally archived by the two-dimensional scanning method. This study aims to try the affective shapely evaluation by three-dimensional archiving of Japanese sword. For the fundamental examination, we designed and manufactured the three-dimensional archiving device by using the stereo digital image correlation method. This paper presents the overview of the manufactured device and the basic measurement results. The goal of this study is to clarify the affective design from the viewpoints of both the shape and the sensual beauty.
Cyclic Stress Measurement Method Using Electrodeposited Copper Foil (The Method Using Fractal Property of Grown Grains) Yuichi ONO and Shota WATANABE The stress measurement method using the fractal analysis of grown grains which occur in an electrodeposited copper foil was examined in this report. The electrodeposited copper foil was adhered to the titanium specimen and cyclic loading test was carried out under bending or torsion condition. Fractal property was observed in the microphotograph of grown grains which occurred by various repeated loading conditions and it became clear that the fractal dimension calculated by the box-counting method depends on the maximum shear stress and a number of cycles. The expression among maximum shearing stress, number of cycles and fractal dimension was proposed based on the experimental results. The combination of this expression and the traditional formula related to the grown grain density enables us to estimate the maximum shearing stress even if the number of cycles is unknown. Moreover, a unique relation was recognized between the grown grain density and the fractal dimension. This means that the fractal dimension can be estimated from the grown grain density. This result suggests that the maximum shearing stress can be obtained only by measuring the grown grain density.
