高强度聚氯乙烯泡沫水声模量参数反演修正

Parameter inversion and amendment of underwater acoustic modulus of high-strength PVC foam

[目的]旨在基于复合材料试样水声插入损失实测值,通过反演算法获得高强度聚氯乙烯(PVC)泡沫的水声模量值,进而提高复合材料水声插入损失计算精度。[方法]首先,通过压缩、平拉等力学试验,得到高强度PVC泡沫材料的静弹性模量,再利用传递矩阵方法计算得到夹芯复合材料的插入损失,并分析得出插入损失计算值与基于脉冲声管法的实测值存在较大差异的原因是芯材弹性模量输入值偏低。然后,基于插入损失实测值,采用遗传算法反演计算出5组泡沫材料的水声模量值。[结果]定量计算结果表明,高强度PVC泡沫的水声模量值高于静弹性模量值,水声模量对压缩模量比值的平均值为1.24,对拉伸模量比值的平均值为1.36。[结论]在对基于高强度PVC泡沫的夹芯复合材料水声性能进行计算时,材料弹性模量输入值应在静力模量实测值基础上正向修正,从而降低误差。

[Objective]The purpose of this paper is to obtain the hydro-acoustic modulus of high-strength polyvinyl chloride(PVC)foam through an inversion algorithm based on the measured underwater acoustic insertion loss values of the composite samples,then improve the calculation accuracy of the insertion loss of the composites.[Methods]First,the static elastic modulus of high-strength PVC foam is obtained through mechanical tests such as compression and tension,and then the insertion loss of the sandwich composite is calculated using the transfer-matrix method.The reason for the large difference in the calculated values and the measured values obtained by the acoustic pulse-based tube method is that the input value of the elastic modulus of the core material is low.Based on the measured insertion loss values,the underwater acoustic modulus values of five PVC foam samples are then calculated via genetic algorithm inversion.[Results]The quantitative calculation results indicate that the hydro-acoustic modulus value of high-strength PVC foam is higher than the measured static elastic modulus values.The average ratio of hydro-acoustic modulus to compressive modulus is 1.24,and that to tensile modulus is 1.36.[Conclusion]When calculating the hydro-acoustic performance of sandwich composites containing high-strength PVC foam,the error can be reduced by positively correcting the input value of the material's elastic modulus on the basis of the measured value of the static modulus.