ULTRASONIC GUIDED WAVE VIBRATION FORMULATION

A novel transient-guided-wave-based approach to predicting natural vibration frequencies and mode shapes of a semi-infinite plate has been developed. This theory uses the orthogonal propagating and evanescent guided wave modes to fully satisfy the elasticity structural vibration boundary value problem for the structure. This technique is able to accurately calculate natural resonant frequencies and full three-dimensional displacement fields in such a plate without making any classical plate theory assumptions, which neglect the crucially important through-thickness displacement field. In addition to solving the three-dimensional elasticity structural vibration problem and developing the through-thickness displacement field, further insight is obtained by relating transient guided wave propagation and steady-state vibration, as well as revealing the relative amplitude and phase of propagating guided wave modes associated with any particular plate vibration mode.