Non-destructive inspection method for mechanical behaviour of article with load, its judgement method and apparatus

This invention inspects non-destructively the mechanical behavior of an article, to which a load is applied, on the basis of analysis of spatial and time distribution of elastoplastic deformation and a rotary displacement speed. Optical images of the surfaces of an object of inspection are taken as holographic images, and they are superimposed in predetermined short intervals of time to obtain a diffraction image. The diffraction image is converted to a wave pattern of a spatial and time distribution of deformation and rotary displacement in a predetermined axial direction. The resulting distribution is analyzed on the wave theory of plasticity and strength, and the wavelength, amplitude and velocity of a mitigation wave of plastic deformation are determined. The timing and place of destruction which will occur in future are predicted from these wave parameters.