A study of guided wave propagation on a plate between two solid bodies with imperfect boundary conditions

In this work, interfacial mechanical properties between solid bodies in contact are monitored by using ultrasonic guided waves. An experimental system formed by two solid aluminum rods (50.8 mm in diameter) axially loaded against a thin aluminum plate to control contact interfacial stiffness was used. Guided waves were excited on the aluminum thin plate using a pitch-catch configuration. The axially applied load on the aluminum rods was varied from 0 MPa to 30 MPa. The effect of loading and unloading cycles on the guided wave propagation parameters was experimentally and theoretically studied. Results of the experiments indicate that applied load affects the attenuation and induces mode conversion of the studied S0 vibration mode. Attenuation as a function of interfacial conditions was numerically determined using the stiffness matrix method and then compared to experimental results.

► All corrections were taken into account.
► Typos in figure labels were corrected.
► A brief discussion on group velocity as indicator of interfacial conditions was included.
► The effect of thickness variation due to loading on mode conversion was briefly discussed.