超薄单向纤维增强复合材料低频多模式超声兰姆波定征方法  

LOW FREQUENCY ULTRASONIC MULTI-MODE LAMB WAVE METHOD FOR CHARACTERIZING THE ULTRA-THIN FIBER REINFORCED COMPOSITE

作　　者：张锐[1] 万明习[1] 陈晓[1] Cao Wen-wu 

机构地区：[1]西安交通大学 生物医学工程系, [2]Intercollege Materials Research Laboratory, Pennsylvania State University, University Park, PA 16802

出　　处：《复合材料学报》2001年第1期20-24,共5页Acta Materiae Compositae Sinica

基　　金：国家杰出青年科学基金资助项目!(6992 5 10 1);美国 Office of Naval Research资助 Grant!(N0 0 0 14 -93 -1-0 3 4 0 )

摘　　要：提出低频多模式超声兰姆波定征方法来估计超薄层状单向纤维增强复合材料的密度、厚度、弹性常数等参数。这里“超薄”的概念是指材料厚度 h远小于材料中的声波波长 λ,导致在时域上材料前后界面的各次回波信号相互混迭。分析了沿平行和垂直于纤维两个方向上 ,在超薄层状单向纤维增强复合材料中传播的低频兰姆波色散特性 ,提出在最小二乘意义下以材料色散曲线为基础的反向算法对材料参数进行了估计。文中分析了影响估计准确性的各种因素 ,研究了该方法对材料参数的灵敏度及其在误差传递中的意义。结合超声漏兰姆波频域分析方法 ,并使用超声耦合剂耦合方式和一对中心频率为 2 MHz的宽带纵波换能器 ,实验结果证实 ,该方法能够准确估计 h<0 .0 5 λ的单向玻璃纤维增强双酚 A型聚砜 (PSF)A low-frequency multimode ultrasonic Lamb wave method for characterizing the thickness, density and elastic constant of ultrathin uni-direction fiber-reinforced composite layer was presented. The thickness of the plate is only a fraction of ultrasound wavelength. The dispersion properties of the Lamb wave propagating along and parallel to the fiber direction were derived, which is the basis of such characterization. In conjunction with the method of least squares, the secant algorithm was used to estimate the parameters of the composite layer. The reasons for evaluating errors of parameters and the sensitivity of all methods for different parameters were analyzed. Using the ultrasound coupler and a pair of broadband longitudinal wave transducers with 2 MHz center frequency can estimate the parameters of the ultrathin GF/PSF composite layer by combination with employing the leaky guided wave frequency-domain analytical method.

关 键 词：超声兰姆波 定量无损定征 色散特性 纤维增强复合材料 

分 类 号：TB332[一般工业技术—材料科学与工程]