Resonance Frequency Characteristics in Weak Bonded Structures

A spring model method is established for researching wave characteristics of the weak bonded structure, which is used to change the resonance frequency and reflection coefficient.According to the relationship between the ultrasonic propagation characteristics and stress-strain condition, the reflection coefficient of the bonding layer with zero thickness is derived.The reflection of wave for equal-thickness aluminum plates under the thickness of the bonding layer is calculated.Analysis and computation show that resonance frequency curves can engender on the shift of "the shift right peaks" with the effect of the variety of the interface stiffness.The influences on the multi-mode resonance frequency of a layered structure with the thickness of the adhesive layer are calculated, and the influence of the "multi-peak" of resonance frequency curves is discussed.