Motion Of Void In Piezoelectricand Electrostrictive Materials And Its Mechanical Behaviours Considering Scale Effect

Piezoelectric materials have stable piezoelectric effect, which canachieve highly efficient conversion between mechanical energy andelectrical energy. While it also possesses many merits like sensitive tophysical properties of machines, heat, sound, light and electricity; lowcost; simply production process etc. All above make piezoelectricmaterials be widely used in many fields. For electrostrictive material, ithas been extensive applied to make precision instruments cause itselectrostrictive effect. However, since defects often appear during themanufacturing of piezoelectric and electrostrictive material. It’s easy toinduce stress concentration around the defect and cause the failure ofmaterial when subjected to loads. So it is necessary to do mechanicalanalysis on defects in piezoelectric and electrostrictive materials and toform a complete mechanical-electrical coupling theoretical model.This paper has obtained the stress and electric field around the voidin the piezoelectric matrix subjected to coupled gradient stress and electrical buy use of complex function、conformal transformation andCauchy-integration. Based on above and consider nonlocal continuumtheory, we studied motion velocity of void in piezoelectric matrixsubjected to various kinds of loads considering scale effect. Thendiscussed effects of void on creep and stress relaxation characteristics ofthe piezoelectric matrix exerted by uniaxial tensile stress. Further more,this paper depicted stresses around the void of electrostrictive matrixcaused by electric field using complex function method and consider theeffect of Maxwell stresses. Finally, the effect of void on the creep andstress relaxation characteristics of electrostrictive matrix has beendiscussed.