【作者】 王东天；

【导师】 何元安；

【作者基本信息】 哈尔滨工程大学 ， 水声工程， 2009， 硕士

【摘要】 吸声覆盖层是覆盖在潜艇表面的一种吸声材料,为了提高吸声覆盖层的吸声性能,吸声覆盖层的设计要综合材料配方设计和声学结构设计两方面来考虑,材料的力学参数是建立吸声覆盖层的结构声学设计与材料配方设计相互关联的纽带。目前的测量方法在水声频段内很难达到精度要求,本文采用声管测量吸声材料复反射系数,然后利用遗传算法反演吸声材料的力学参数,这种方法解决了在5kHz-30kHz频段内的声学材料力学参数的测试问题,而且达到了很高的精度。首先,讨论声波在均匀材料中的传播特点,由此建立材料力学参数与声管测量均匀样品的声学参数之间的联系,然后通过声学参数反演材料的体积纵波模量。其次,研究声波在无限长的圆柱管中的传播特点,建立弹性圆柱管中振动位移的波动方程,代入边界条件,得到方程的一阶、二阶近似解。利用一阶、二阶近似解建立等效参数原则,将圆柱管等效为均匀材料。带有均匀圆柱腔的样品,由于结构对称、重复。对其中一个圆柱管进行研究,利用之前建立的等效参数原则,将带有均匀圆柱腔的样品的声学参数与材料剪切模量G和拉米常数兄之间建立关系,将之前由均匀样品反演得到的体积纵波模量作为己知量代入,可以求得剪切模量。在由声学参数反演材料力学参数时,需要对超越方程进行求解,此过程引入遗传算法,提高反演的精度。利用MATLAB编写程序,对声管测量的均匀样品和带结构样品进行仿真,仿真各个参数对样品吸声性能和反演材料力学参数的精度的影响,为设计试验样品提供了依据,对算法和材料参数反演理论进行仿真,验证遗传算法反演材料参数的稳定性和反演理论的可行性。基于理论基础和仿真分析结果,制备了实验样品,进行声管测量试验,对均匀样品和带结构样品进行多次测量,验证声管测量的稳定性。利用各次测量结果的均值,反演材料力学参数,将得到的结果与相位法测量结果进行对比,验证测量方法的可行性。更多还原

【Abstract】 The anechoic coating is the sound absorbing material which is covered in the submarine surface. To enhance the anechoic coating’s sound absorption performance, we should the anechoic coating’s design which must synthesize the sound material compound design and structural design two aspects. The material mechanics parameter is the bridge of the anechoic coating’s structure acoustical design and the sound material compound design. The present measuring technique is hard to meet accuracy requirement in the underwater sound frequency band. In this article, sound absorber duplicate reflection factor is measured using sound pipe and genetic algorithm is used to deduce sound absorber’s mechanics parameter, this article uses the sound pipe survey sound absorber duplicate reflection factor, then the use genetic algorithm inversion sound absorber’s mechanics parameter. This method has solved acoustic material mechanics parameter test problem in the 5-30kHz frequency band, and has achieved higher precision.Firstly, discussing the characteristic of sound wave propagation in the symmetrical material, from this establishing relationship between the materials mechanics parameter and symmetrical sample acoustics parameter which surveyed by sound pipe, then inversion material the volume longitudinal wave module through acoustics parameter. Next, researching characteristic of sound wave propagation in the infinite long column tube, establishing vibrate displacement’s wave equation in the elastic column tube, the equation first-order, the second-order approximate solution was obtained by substituting the boundary condition. Using the first-order and second-order approximate solution establishes equivalent parameter principle, the column tube is equivalent to the symmetrical material. Structure of the symmetrical column cavity sample is symmetrical and redundant. Using the equivalent parameter principle establishes mentioned before to study one of column tubes, establishing the relationship between symmetrical column cavity’s acoustics parameter and shearing modulus and Lame of material. Using volume longitudinal wave module inversed by the symmetrical sample obtained which obtains in the preceding text may get the modulus of shearing. Acoustics parameter inversion materials mechanics parameter needs to carry on the solution to the transcendental equation, this process introduction genetic algorithm, enhancing the inversion the precision.Using MATLAB writing program, carrying on the simulation to the symmetrical sample and the structure sample, computing each parameter’s influence to precision of the sample sound absorption performance and the inversion materials mechanics parameter, providing the basis for the design of test sample, carries on the simulation to the algorithm and the material parameter inversion theory, proving that genetic algorithm inversion material parameter is stability and the inversion theory is feasibility.Based on the rationale and the simulation analysis result, making the experiment sample and carrying on the sound pipe survey experiment, carries on the multiple metering to the symmetrical sample and the structure sample, it proves that sound pipe surveying is stability.average value of measurement results is used to inverse material mechanics parameter. Contrast the result to phase method measurement result, proving measuring technique feasibility.更多还原