| The daily display,storage or handling of fragile items such as cultural relics is easily affected by external environmental factors,such as rising temperature or irradiation erosion.If there are tip cracks on or inside the cultural relics,external environmental factors will aggravate the growth of cracks,thereby cause further damage to cultural relics.Therefore,it is of great significance to detect tip cracks in cultural relics and other fragile objects and grasp their growth regulars under the influence of different external environmental factors.In the detection of microscopic parameters,digital holography technology has unique advantages,such as non-contact,high precision,real-time,fast and so on.This paper by means of digital holography,aim at the transparent medium material(Dammar Varnish),which is often used for the surface sealing protection of oil painting cultural relics,to carry out the transparent material tip crack growth holographic testing experiment research,the aim is to simulate the growth and change of tip crack in the surface protective layer material of oil painting cultural relics under the influence of different environmental factors.To provide a feasible and effective technical means for the protection and detection of related cultural relics.The main work contents of this paper are summarized as follows:(1)Design of holographic detection method for tip cracks of transparent materials;Based on the principle of digital holography technology and the growth mechanism of tip cracks,the research plan and content of holographic detection of tip crack growth are proposed.(2)Experimental research on holographic detection of heated growth of transparent material tip cracks;Based on an inverted biological microscope,a Mach-Zehnder hologram recording system was designed and constructed,and a warm lamp was used to apply external heat to simulate Damar varnish in a heated environment holographic detection of material tip cracks,and analysis of the growth situation of tip cracks in a heated environment based on the phase change of the hologram reconstruction.(3)Experimental research on the holographic detection of the tip cracks of transparent materials irradiated by laser.The multi-spectral laser is used to design and construct a dual optical path system for laser irradiation and Mach-Zehnder hologram recording.The laser precise irradiation method is used to simulate the holographic detection of the tip cracks of the Damar varnish material under the irradiation environment.Analyses laser absorption characteristics of different wavelengths and the growth regular of tip crack under the laser irradiation. |
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