We have derived four new stress field factors by taking into account the interaction effects between the inclusions in a 0-3 composite material and then used them to calculate the two effective piezoelectric coefficients (d 31 and d 33 ) for some 0-3 piezoelectric composite materials. Predicted values are compared with published experimental data and it is found that they agree with each other reasonably well, even with a high volume fraction of the inclusions.
Acknowledgment
This work is supported by an internal research grant (G-RGT5) and the Centre for Smart Materials of The Hong Kong Polytechnic University.