Numerical analysis of the overlap area in guided wave propagation in bonded Aluminum lap joint plates

In this research, the purpose is to investigate the effect ofthe lap joint plates in a guided wave signal which is usedextensively in defect detection methods. The modelincludes two Aluminum plates and two piezoelectric usedas a sensor and an actuator. The plates are bonded to eachother by a constant pressure. This paper consists of threemain sections. In the first, the energy transmission isdetermined for different overlap lengths. Eight differentlengths are studied in this section. The index formeasuring the amount of transmitted energy is themaximum voltage of the received signal in the sensor. Itshows that by increasing the overlap length thetransmission energy increases too, however, after the timethat output signal reaches to its maximum value itdeclines. In the second part, the group velocities arecalculated for the structures that have the same ratio of theoverlap length to the distance between a sensor and anactuator. For this purpose four different structures areinvestigated. The results show that for the same ratio ofthe overlap length to the distance between the sensor andthe actuator the group velocity does not change. In thethird part, the group velocity is studied in greater details.In fact, it is calculated in three main regions including theareas before the overlap area, after it and in the overlapregion. It is observed that the actuated wave has differentgroup velocity from the other parts which means thatthere is a mode conversion in the lap joint region

کلیدواژه ها:

lap joint plate ، guided wave ، numericalanalysis ، SHM