Electromechanical modeling using explicit time-domain finite elements

Piezoelectric transducers serve as electromechanical transceivers in sonar, medical imaging, NDE, and signal processing systems. Despite their relative technical maturity, many opportunities for improvement and innovation remain. To best exploit these opportunities we need to augment standard design procedures based on 1D models and prototype experiments. Rigorous finite element computer modeling offers a powerful adjunct to conventional methods, yet it has enjoyed only limited acceptance despite major industry efforts. One reason is reliance on traditional implicit numerical algorithms for frequency-domain analysis or time integration. We present an alternative mixed explicit/implicit algorithm for direct time-domain integration of the 2D or 3D electromechanical equations. On the same workstation it affords about two orders of magnitude faster solutions or larger models than do available implicit codes, and makes desktop transient device modeling practical. This paper reviews algorithms, presents validation calculations, describes 2D and 3D array simulations, explores associated wave propagation issues, and considers future directions