CAJ | 학술논문

提出一种通过测量黏弹性空腔覆盖层反射系数，结合有限元法计算黏弹性材料动态力学参数的方法。分别测量黏弹性空腔覆盖层在两种不同背衬条件下的反射系数，并根据黏弹性空腔覆盖层反射系数的有限元计算模型，建立求解黏弹性材料动态力学参数的二元方程组。利用二元非线性方程组求根的牛顿迭代法，求解方程组可以获得黏弹性材料的复纵波声速和复剪切波声速，进而计算复弹性模量和复泊松比等其他黏弹性动态力学参数。在水声声管中采用双水听器法测量某种聚氨酯材料样品的反射系数，获得了黏弹性材料的动态力学参数，并讨论试验误差对结果的影响：当双水听器的幅值不一致时，对复弹性模量和复泊松比实部的影响较大；当双水听器的相位不一致时，主要影响复弹性模量和复泊松比实部的损耗因子。
제출일충통과측량점탄성공강복개층반사계수，결합유한원법계산점탄성재료동태역학삼수적방법。분별측량점탄성공강복개층재량충불동배츤조건하적반사계수，병근거점탄성공강복개층반사계수적유한원계산모형，건립구해점탄성재료동태역학삼수적이원방정조。이용이원비선성방정조구근적우돈질대법，구해방정조가이획득점탄성재료적복종파성속화복전절파성속，진이계산복탄성모량화복박송비등기타점탄성동태역학삼수。재수성성관중채용쌍수은기법측량모충취안지재료양품적반사계수，획득료점탄성재료적동태역학삼수，병토론시험오차대결과적영향：당쌍수은기적폭치불일치시，대복탄성모량화복박송비실부적영향교대；당쌍수은기적상위불일치시，주요영향복탄성모량화복박송비실부적손모인자。
Based on measuring the reflection coefficient of viscoelastic layer and using the finite element method, the calculation method of viscoelastic dynamic mechanical parameters are developed. Measuring a viscoelastic layer specimen under two different acoustic backings will result in two different reflection coefficients, and using the finite element model to solve the reflection coefficient of viscoelastic layer, two nonlinear equations which are used to calculate viscoelastic parameters will be obtained. Using Newton iteration method to solve the two equations, the complex longitudinal and shear wave speeds of viscoelastic material will be obtained. Thus, the complex elastic modulus and complex Poisson’s ratio will be derived easily. The viscoelastic dynamic mechanical parameters, such as complex elastic modulus and complex Poisson’s ratio of polyurethane have been measured, and the effects of measurement errors on the viscoelastic dynamic mechanical parameters are discussed:The real parts of complex elastic modulus and complex Poisson’s ratio are mostly sensitive to the difference of two-hydrophone magnitude, and the loss factors of complex elastic modulus and complex Poisson’s ratio are highly related to the difference of two-hydrophone phase.