压电材料中含绝缘裂纹与导通裂纹的微结构干涉研究

he influence of microstructures e.g. microcracks on the near-tip stress-electric field for an impermeable macrocrack in piezoelectric materials was studied using the existing pseudo-traction methods. The macrocrack could be modeled as impermeable one for its surrounding insulation environment whilst the microcracks could be modeled as permeable slit cracks due to poling or other sources without the crack surface opening effect. The conservation of the J-integral holds true for the configuration with a permeable microcrack near the tip of an impermeable macrocrack. Finally, the influence of the permeable microcrack on the macrocrack tip could be modeled as the stress intensity factor (SIF), electric displacement intensity factor (EDIF), and mechanical strain energy release rate (MSERR) in comparison with the previous work. It is found that the divergences between the present permeable microcrack model and the previous study are remarkable under combined electric-mechanical loading. The disturbance of the permeable microcracks on the near-tip stress-electric field due to the positive electric field loading is always much smaller than that given in the previous impermeable model.