Abstract
A number of well established analytical and numerical modelling techniques of classical extension bimorphs are assessed and evaluated using general purpose finite element codes. This allows the clarification of several confusing common validation practices, using well known experimental data and analytical formulas. New analytical formulas are presented and evaluated for the first time for the relatively new shear bimorph concept and a more general extension-shear one, resulting from the combination of the extension- and shear-piezoelectric modes via an off-axes polarisation.