粘接结构波动特性的矩阵表示法及参数影响

Matrix Representation of Fluctuation Characteristics of Adhesive Structure and Parameter Influence

为丰富多层复合材料界面形态检测方式,笔者构建了一种声波传播界面矩阵模型。分别用空气和水模拟粘接结构的界面为脱粘和进水状态,导出了横波入射下的多层结构中的声反射和透射系数表达式;研究了超声波与不同形态界面的相互作用,分析了入射角度对声波传播特性的影响。结果表明:当横波入射角度介于30°~40°或30°~60°之间,分别采用横波的反射系数法或透射系数法可较容易区分出完好连接、脱粘以及进水界面;除了0°、临界角和90°外,采用纵波透射系数法也较容易鉴别界面形态;无论横波入射角度为多大,采用纵波反射系数法均不能很好地区分脱粘和进水界面。该方法为实验时采用超声波检测粘接结构提供了依据。

To enrich the detection methods of interface morphology for multi-layer composite materials,an acoustic wave propagation interface matrix model was constructed.The debonding and water inlet statuses of adhesive structure interfaces were simulated by using the air and water respectively,the expressions of acoustic reflection and transmission coefficients in multi-layer structure with transverse wave incidence were deduced,the interaction between ultrasound and different interfaces was studied,and the influence of incident angle on the propagation characteristics of acoustic waves was analyzed.The results show that when the incident angle of transverse wave is between 30°~40°or 30°~60°,the well-connection,debonding and water inlet interfaces can be better identified by using the reflection coefficient method or transmission coefficient method of transverse wave,respectively.In addition to 0°,the critical angle and 90°,interface morphology can also be easily identified by using the longitudinal wave transmission coefficient method.Regardless of the incident angle of the transverse wave,the method of longitudinal wave reflection coefficient cannot distinguish the debonding and water inlet interfaces.The proposed method provides a basis for the experimental detection of adhesive structure by ultrasound.