Electro-mechanical creep of 1−3 piezocomposites: Theoretical modeling and experimental approach

Experimental and theoretical characterization on creep behavior of 1−3 piezocomposites subjected to a constant electric field and mechanical pre-stress is carried out. For curved surfaces or systems undergoing large deformations, piezo-ceramics are unsuitable since these are brittle in nature. Hence, piezo-composites are used as replacements. Creep is an important aspect with these systems due to a softer viscoelastic matrix involved. Electrical and electro-mechanical creep are studied for these systems. Electrical creep is observed to be maximum at the coercive field. Also, it is inferred that the volume fraction of fiber in 1−3 piezocomposites affects the system performance. The electro-mechanical creep is observed to reduce exponentially with increasing compressive pre-stress. Mechanical depolarization effect is observed during compressive loading. A thermodynamically-consistent macro-mechanical model is proposed to capture the creep behavior of 1−3 piezo-composites. It is found that the model predictions are in agreement with the experimental observations.