抄録
Numerical simulations with finite a domain time domain (FDTD) method for Zero-group-velocity Lamb waves in mono plate and adhesive plate models were carried out. In the FDTD method, calculation accuracy for ZGV Lamb wave frequencies depended on the ratio of space discretization size to thickness of the plate model (dx/d) and were less than 2.6 % in dx/d<0.01. Vibration modes of ZGV Lamb waves would be formed with interference between multiple echoes of longitudinal and shear waves mode-converting at each reflection at the surface. Calculation of ZGV Lamb waves for weak bond condition was expressed by applying a liner slip spring condition as a boundary condition at bonding line. The frequencies of some modes of ZGV Lamb waves in the weak bond model slightly reduced compared to those in the perfect bond model.
