基于数值-解析方法测量静压条件下阻尼材料动态力学参数

建立了一种测量静压条件下阻尼材料动态力学参数的数值-解析方法。首先，分别制作两种空腔半径不同的圆柱空腔覆盖层样品，测量两种样品在静压力下的复反射系数。其次，采用有限元法仿真静压力下的空腔结构变形，在此基础上同样采用有限元法计算复反射系数。以实测复反射系数和计算复反射系数建立二元非线性方程组，利用牛顿迭代法求解方程组可获得复弹性模量和复泊松比等黏弹性动态力学参数。对聚氨酯材料制作的样品进行了复反射系数测量，分析了静压力对聚氨酯材料动态力学参数的影响规律。最后，测量了某不同结构吸声覆盖层静压下的反射系数，并与采用实测材料参数计算的反射系数进行了比较，验证了该方法的正确性。

Dynamic parameters measurement of damping materials under hydrostatic pressure based on a hybrid numerical-analytical method

The viscoelastic dynamic parameters measurement of damping materials under hydrostatic pressure based on a hybrid numerical-analytical method has been developed. First, two different samples of sound absorption coatings which contain cylindrical holes with two different radii will be tested in order to obtain the two different measured complex reflection coefficient under hydrostatic pressure. Second, the simulated complex reflection coefficient should be carried out based on the structural deformation calculated by using the FEM method. Then, taking account of the measured and the simulated complex reflection coefficients simultaneously, two nonlinear equations will be formed. Using the Newton iteration method to solve the nonlinear equations, the viscoelastic dynamic parameters including the complex elastic modulus and the complex Poisson’s ratio will be obtained. Then, two samples made by the polyurethane have been tested in the water-filled acoustic-pipe, and the effect of hydrostatic pressure on the viscoelastic dynamic parameters has been analyzed and summarized. Finally, the reflection coefficient of another different sound absorption coating which has been tested under hydrostatic pressure, compared with the simulated reflection coefficient from which the viscoelastic dynamic parameters is measured above, demonstrates that the present method is correct.