基于共线混频的粘接界面固化非线性超声评价

Nonlinear ultrasonic evaluation of bonding interface curing based on collinear frequency-mixing

共线混频法是一种非常有效的非线性超声检测方法。该方法利用两列波在介质中的非线性相互作用特性,实现对材料力学性能的无损检测与评价;首先利用有限元软件ABAQUS,对粘接胶层中含随机分布微裂纹的模型进行共线混频数值模拟,得到共振波幅值随胶层微裂纹数的变化情况,随后以6061铝合金/改性丙烯酸酯胶/6061铝合金粘接试件为研究对象,采用共线横波和纵波混频检测技术,试验研究共振波幅值随粘接界面固化时间的变化情况。结果表明:共振波幅值与粘接胶层中随机分布的裂纹数、粘接试件的固化时间之间存在内在联系;随着裂纹数的增加,共振波幅值不断减小;随着固化时间的增加,共振波幅值不断增大,直到固化完成共振波幅值趋于稳定;因此,利用共线混频技术可实现对粘接界面固化过程的有效监测和评价。

Collinear frequency-mixing method is a very effective nonlinear ultrasonic testing method.With this method,nonlinear interaction characteristics of two waves in medium is used to realize nondestructive testing and evaluation for mechanical properties of materials.Here,firstly,the collinear frequency-mixing numerical simulation of the model with randomly distributed microcracks in bonding layer was performed by using the finite element software ABAQUS,and the variation of resonance amplitude with number of microcracks in bonding layer was obtained.Then,taking 6061 aluminum alloy/modified acrylate adhesive/6061 aluminum alloy bonding specimen as the study object,the variation of resonance wave amplitude versus curing time of bonding interface was experimentally studied by using the collinear shear wave and longitudinal wave frequency-mixing detection technique.The results showed that there is a certain internal relation among resonance wave amplitude,number of randomly distributed cracks in bonding layer and curing time of bonding specimen;with increase in number of cracks,resonance wave amplitude decreases continuously;with increase in curing time,resonance wave amplitude increases continuously until curing is completed,and then its size tends to be stable;the collinear frequency-mixing technique can effectively monitor and evaluate curing process of bonding interface.