镁合金粘接层失效的非线性超声检测研究

摘要

A non-linear ultrasonic system for testing the debonding of the adhesive layers which is expected to influence the overall performance of materials or structures was established. On which this non-linear ul-trasonic non-destructive testing method was used to test specimens thereof on magnesium alloys with differ-ent degrees of debonding. By doing so, the ultrasonic non-linearity parameterβwas measured effectively. The experimental results demonstrated that the ultrasonic non-linearity parameter was sensitive to the debond-ing of the adhesive layers of the magnesium alloys, and exhibited a quadratic relationship with the degree of debonding as the latter increases. Besides, a finite element simulation model was established to perform nu-merical simulation of the specimens of the adhesive layers of magnesium alloys which had debonded to dif-ferent degrees. The simulation and experimental results had a same change tendency, which further demon-strated that the proposed non-linear ultrasonic testing technology is applicable to the non-destructive evalua-tion of the debonding of the adhesive layers.%粘接层脱粘问题直接影响材料或结构的整体性能,需要采用合适的方法尽早检测.针对此问题,提出利用非线性超声无损检测方法对其进行检测,建立了粘结层失效的非线性超声测试系统,对脱粘不同程度的镁合金粘结层试件进行了试验研究,有效测量了表征粘接层失效程度的超声非线性系数β,结果表明超声非线性系数对镁合金粘结层失效非常敏感,且随脱粘程度呈二次函数关系增加;同时,建立了有限元仿真模型,对脱粘不同程度的镁合金粘结层试件进行了有限元数值仿真,仿真结果和实验结果在变化趋势上近似一致,进一步证明非线性超声检测技术可以用于粘接层界面失效的无损评价.