Estimation of Elastic Stiffness Coefficients of Glass Flake Lining by the Simplex Assisted Inverse Processing of Orientation Dependence Laser-excited Surface Acoustic Wave Velocities

摘要

Glass flake lining (GFL) is a composite material with fish-scale shaped glass flakes and polymer. It is a typical transverse isotropic materials with a symmetric axis along the surface normal of the lining. Study aims to estimate five elastic stiffness coefficients of GFLs by the inverse processing of surface acoustic wave velocities measured on the transverse section by a laser SAW system. Phase velocities of both the surface skimming compressive wave (SSCW) and Rayleigh wave were measured for non-coated (as-polished) and aluminum-coated GFLs, respectively. We estimated elastic stiffness coefficients utilizing the simplex-assisted inverse processing of the orientation dependence of the Rayleigh and/or SSCW velocities. Four coefficients C_(11), C_(33), C_(44) and C_(66) (direction 3 being the lining's normal) were estimated with sufficient accuracy while the estimation accuracy of C_(13) was poor due to weak effect of it on the velocity anisotropy.