粘弹性夹杂功能梯度层合板的水下吸声性能及其计算方法研究

The multiphase inclusions and the functionally graded materials (FGM) are the directions of future for sound absorption and impedance matching, respectively. A new type of multiphase inclusion FGM is developed to give consideration to both sound absorption and impedance matching. According to the features of sound absorption and that of viscoelastic multiphase inclusion FGM, researches are carried out on the two key scientific problems, which are "the viscoelastic constitutive relation and the homogenization method for multiphase inclusion FGM under different temperature conditions" and "the computation method for the dynamic response of FGM laminated plates while considering the fluid-solid interaction (FSI)". 1 The creep test are performed, and the Burgers viscoelastic constitutive parameters are obtained by fitting the experiment datas. 2 The viscoelastic constants of the multiphase inclusions FGM are forecasted by the generalized self-consistent Mori-Tanaka homogenization method and the representative volume element method. 3 Based on the numerical inversion of Laplace transform and the Peano-Baker series method, a new state-space method is develop for the transient responses of FGM laminated plates with arbitrary gradient. Considering the FSI, a state-space method for the laminated plate with a weak interface is developed. 4 From a perspective of energies, an evaluation index is developed for the sound absorption, and the sound absorption mechanics are researched. 5 The underwater standing wave tube experiment is performed, and the test results are used to verily that calculated by the state-space method.

夹杂和功能梯度两种结构分别代表了水下吸声材料在吸声机理和阻抗匹配的发展方向。提出了一种兼顾机理与功能的粘弹性夹杂功能梯度水下吸声结构。针对水下吸声领域和粘弹性夹杂功能梯度层合板的特点，围绕"不同温度条件下夹杂功能梯度材料的粘弹性本构及均匀化方法"和"考虑流固耦合条件下功能梯度层合板的动力响应计算方法"两个关键科学问题展开研究：1采用蠕变试验拟合不同温度条件下聚氨酯基体和粘结剂的Burgers粘弹性本构模型；2基于广义自洽Mori-Tanaka均匀化和代表性体积元方法预测夹杂功能梯度材料的粘弹性常数；3结合Laplace逆变换和Peano-Baker级数方法建立可以计算瞬态荷载作用下任意分布功能梯度层合板动力响应的状态空间方法，建立考虑流固耦合且含粘弹性弱界面的层合板的动力响应计算方法；4提出基于能量的吸声减振性能评价指标，研究吸声减振机理；5开展水声驻波管试验，并验证解析计算结果。

夹杂和功能梯度两种复合结构分别代表了水下吸声材料在吸声机理和阻抗匹配的发展方向。提出了一种兼顾机理与功能的粘弹性夹杂功能梯度水下吸声结构。然而尽作者所能，目前尚未看到有任意边界条件下复合结构瞬态动力响应解析和半解析解的相关报道。因此，本文结合状态空间法、数值Laplace逆变换方法和微分求积方法，提出了一套任意边界条件下复合结构瞬态动力响应的半解析求解体系，并将该体系应用于环形功能梯度板、扇环形功能梯度板、圆柱壳和矩形功能梯度板等复合结构的瞬态动力响应求解。将Taylor一维流固耦合理论由一维拓展到三维，结合上文所述求解体系，提出一套水下冲击荷载作用下层合板瞬态动力响应的半解析求解方法。此外，针对功能梯度薄板，结合Laplace变换和Kirchhoff薄板理论，还提出一套解析求解方法。将半解析方法的计算结果与有限元方法、文献中的其他解析方法的计算成果或试验结果进行比较，并进行收敛性分析，验证了本文所提出的半解析求解体系的正确性。此外，还进行了边界条件、材料梯度参数、地基参数、几何参数的影响性分析。