Study on electroelastic field concentration around the electrode tip in multilayer ferroelectric actuators of two designs and their optimizations

摘要: Abstract Distribution of electromechanical field near electrode tips is closely related to the reliability ferroelectric multilayer actuators. In this paper, deformation and stress concentrations around tip in two actuator designs, partially fully cofired, are investigated by means experimental measurement numerical simulations. The digital speckle correlation method (DSCM) used measure full displacement with high spatial resolution. paths electric breakdown cracks initiated from edge electrodes were observed. With proposed Double Gibbs free energy criterion, a coupled nonlinear finite element based on domain-switching mechanisms developed simulation results agree well experiments. It found that crack-like “defects” cofired layered actuators, i.e. interlayer gaps filled soft insulating wax, can significantly reduce maximum tensile level compared “perfect” which implies design more reliable than one. Further optimization geometrical dimension actuators also carried out.