Papers by Keyword: Phase Map

Abstract: The Electronic Speckle Pattern Interferometry (ESPI) is a widely used technique for measurement displacement and deformation. But the fringe phase pattern of ESPI always comes with large noise when using phase-shifting technique. In order to ensure the accuracy of the measurement, it is very important to eliminate the noise of the phase fringe pattern. This paper introduced a phase filtering method, comparing with traditional methods, which can be found is a simple and effective method, and the experimental results have shown that the method was feasible used for image processing of ESPI fringes．

Abstract: The grain boundary oxidation mechanism in hot rolled chromium – manganese steels during heat exposure at 700 °C was mathematically modeled. Given a fixed exposure time, the migration of the atomic species (iron, oxygen, chromium and manganese) has been calculated with the parabolic rate equation for diffusion. After each small time step, the data was transferred into the database ChemApp (GTT-Technologies, Germany) to calculate the oxide composition for each point in thermodynamic equilibrium. The concentration for each phase was illustrated in a phase map, similar to a cross section polish of the respective specimen. Total element concentration is shown as density plot to give a better comparison with experimental pictures from EDX or AES measurements. The obtained results are in good agreement with experimental data for alloyed steel samples with an element concentration below the critical concentration of protective oxide scale formation.

Abstract: Impulsive vibration generated by localized gear damage can be used as an indicator for damage detection. Local damage induces an abrupt increase of the amplitude and phase lag of the impulsive vibration signal measured on the gearbox. Relatively large damage like “tip breakage” can be easily detected by the amplitude map of CWT (continuous wavelet transform) for the impulsive vibration signal measured on the gearbox. However, minor damage like “initial pitting” cannot be detected with the amplitude map. To overcome this problem, in this paper we take into account the phase map for a damage signal. The zoomed phase map of CWT is successfully applied to the detection of minor gearbox damage.