The high performance of finite element analysis and applications of surface acoustic waves in finite elastic solids

The characteristic of wave propagation in finite elastic solids is a major issue for surface acoustic wave (SAW) devices, which are designed based on accurate analysis. As a result, it is essential in engineering applications to analyze the SAW propagation in finite piezoelectric solids with the objective of revealing the influence of structural changes. As the finite element analysis of solids is already sophisticated, the problem of SAW analysis is reduced to the calculation of eigenvalues of extremely large linear equations that involves hundreds of thousands or even millions of degree of freedom because of the higher frequency. The operations of large scale matrices need high computing speed and large memory. In fact, these demands are beyond the capacity of widely available computing resources. For these reasons, we need to make use of computer clusters and parallel finite element method to improve the computing efficiency and expand applications. Based on our existing finite element program, the PARPACK package is used to compute eigenvalues in the specified range; the compressed sparse row (CSR) storage format is used to replace the Symmetric Skyline (SSK) storage method; the PETSc package is used to solve linear equations. The program is parallelized on a Linux cluster to utilize the computing power. The parallel FEM program with 3D elements is used to analyze the wave propagation in an actual SAW device model with interdigital transducers.