Multilayer piezoelectric actuators are commonly used to control injection valves in modern combustion-engines. Their structural and functional integrity is associated with the loading conditions as well as with the actuator-design. In service mechanical stresses are an inherent loading scenario of such electro-mechanical converter components. Internal inhomogeneous mechanical and electrical fields may harm their integrity and accelerate phenomena such as degradation, fatigue and subcritical crack growth. A way to delay these phenomena is to reduce the tensile field-amplitudes by operating these piezoelectric components under a low compressive bias-stress. However, this also may influence the component's performance. Interestingly, this bias-stress enhances its strain characteristics.
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