Sonic Inspection of Bonds in Viscoelastic Composites
Vibration isolation is frequently accomplished by placing rubber pads between a structure and its foundation. In typical industrial situations, the weight of the structure can be used to keep the pads in place and to ensure contact at the interface. However, when dampers are used for small electronic components, they are frequently glued to the component and to the support. The total unit then consists of the component, a glue interface, the rubber damper, a second glue interface, and the foundation. If the interfaces fail, compressive waves can usually be transmitted, but tensile stress waves encounter the separated layer which markedly affects the transmissivity and damping. Consequently, the damper effectiveness generally is reduced. Many modern dampers employ viscoelastic rubber whose frequency characteristics and damping rely less upon resonance than upon the wide frequency spectrum of damping .
KeywordsReflection Coefficient Viscoelastic Material Vibration Isolation Rubber Damper Dilational Wave
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