基于复虚场方法的亚克力薄板黏弹性本构参数识别

To investigate new methods in the field of material parameter inversion,a complex virtual fields method is proposed for solving the elastic constants of orthogonal anisotropic composite materials. To lay the groundwork for the inversion of orthogonal anisotropic constitutive parameters,an isotropic material, polymethyl methacrylate (PMMA),is initially used as an experimental specimen. Based on thin plate theory and deflectometry,a vibration loading test is conducted on a thin plate specimen to acquire the full-field deformation of the specimen surface. The measured deformation field is processed using C³ continuity Hermite finite elements,resulting in the out-of-plane displacement and curvature fields of the thin plate specimen. The complex virtual fields method is then used to calculate the viscoelastic constants of material. The inversion results are compared with the elastic parameters measured by the three-point bending test and the damping coefficients measured by the cantilever beam hammer impact test. The experimental results show that the measured errors of the elastic modulus and damping coefficients are all within 0. 3%. This confirms the feasibility of the proposed method in the inversion of isotropic constitutive parameters and lays the foundation for the subsequent inversion of anisotropic material constitutive parameters.