Zhou Chang-Zhi et al 2008 Chinese Phys. Lett. 25 1336 doi:10.1088/0256-307X/25/4/047
Zhou Chang-Zhi1, Li Ming-Xuan1, Mao Jie1 and Wang Xiao-Min1
Show affiliationsWe investigate the relationship between natural frequencies of a multilayered system of different elastic materials and the thickness of the undermost thin film. The natural frequencies are numerically calculated from the reflection coefficient of a sample system of "steel-epoxy resin-aluminium-thin polymer" with normal incidence. Strain energy ratio is defined and calculated to give the physics explanation why some frequencies are sensitive to thickness of the thin film in certain range. Experiments of three specimens indicate that the measured natural frequencies agree well with the theoretical ones. It is found in our experiments that the ratio of the lowest film thickness to wavelength is about 1/5. The average relative errors for the inverted polymer film thicknesses are found to be 11.8%, -4.8% and -1.3%, respectively.
68.55.-a Thin film structure and morphology
68.60.Bs Mechanical and acoustical properties
Soft matter, liquids and polymers
Issue 4 (April 2008)
Received 19 January 2008
Zhou Chang-Zhi et al 2008 Chinese Phys. Lett. 25 1336
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