SH guided wave detection method for interfacial state of bonded structure

Abstract

The invention provides an SH guided wave detection method for the interfacial state of a bonded structure. An expression containing a tangential rigidity coefficient K<T> for the reflection and transmission coefficients of a minimum-grade SH guided wave mode (SH<0>) in a plate-shaped bonded structure is deduced based on the governing equation of wave propagation. Taken an aluminum / epoxy resin / aluminum bonded structure as an example, the relation between incident angles and reflection or transmission characteristics of SH guided waves in different interfacial states is analyzed when the incident frequency f of the SH guided waves and the thickness h of a bonding layer are respectively set at specific values. Meanwhile, the influence of the product of frequency and thickness on reflection or transmission characteristics of the SH guided waves is discussed when the incident angles of the SH guided waves are set to be 0 DEG and 50 DEG C. How to discriminate interfacial states is also elaborated. Compared with other detection methods, the SH guided wave detection method for the interfacial state of the bonded structure has the advantages of easiness, effectiveness and practicability.

Description

technical field [0001] The invention belongs to the field of non-destructive testing, and in particular relates to an SH wave testing method for the interface shape of an adhesive structure. Background technique [0002] Adhesive structures are widely used in machinery, construction, electronics, aerospace and other fields due to their superior properties such as specific strength, high specific modulus, sealing, and vibration reduction. The bonding quality is mainly determined by the bonding process. During the implementation process, it is affected by factors such as the quality of the adhesive and the design of the bonding process. Pores, weak bonding, shear slip, and local debonding are prone to occur at the interface. Defects seriously affect the mechanical properties of the bonded structure. Therefore, the detection and evaluation of the interface quality of the bonded structure has important research significance. At present, ultrasonic testing has become one of the...

AI Technical Summary

Problems solved by technology

After our research on a large number of published literature and actual industrial sites, we found that there are still the following problems to be solved urgently in the discussion of bonding structures: (1) The current research is mainly inclined to simulation or experiment, and there is still a lack of necessary theory In particular, there is a lack of theoretical research on the use of SH waves to identify the interface morphology of bonded structures; (2) Weak bonding is a very important and special interface form, but most of the contact interfaces targeted by literature are mostly intact or disconnected. In the viscous state, there is no research on the SH wave propagation characteristics in the bonded structure under the weakly bonded interface

Images