The finite element method is a mathematical technique which, based on the governing differential equations, allows the precise numerical computation of boundary value problems for arbitrary geometries. Traditionally, the finite element method is applied in mechanics and civil engineering, having its roots in these faculties as well. In electromechanical engineering, however, it is emerging since the last decade. The main reason for that delay is the following: for the simulation of electromechanical tranducers, such as ultrasound transmitters and receivers, for example, a coupled field problem has to be solved which causes much more effort than handling a single field as is the case for purely mechanical components.
In most cases, this coupling is even twofold: first, one has to describe the internal coupling mechanism of an electromechanical transducer, such as the piezoelectric effect or the electromagnetic effect. Secondly, the interaction of a fluid (propagation medium) and a solid (transducer) has to be considered. When the propagation of a sound wave in a huge (unbounded) domain has to be computed, further difficulties may arise, demanding special elements, such as infinite elements, or adapted procedures.
Meanwhile, finite element codes have overcome many of these difficulties and, the engineer may rely on finite element simulations for the design of electroacoustic components, such as ultrasound equipment. There are some facts promising an emerging growth and a future success of finite elements or related techniques such as the boundary element method. The requirement of industry to speed up the design phase of their products can be met only by relying on such precise simulation tools. On the other hand, the large computer resources necessary to handle the above mentioned multi-field problems by finite elements or related numerical techniques, are becoming more cost-effective from month to month.
Reinhard Lerch
Associate Editor
1997 IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 44:537
© 1997, by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.