Discussion Forum

Hi,

I have a question regarding the strain and the voltage generated in a u-shape piezoelectric beam. I have included the picture for clarity. When I exert the inward force, the u shape beam is strained. From theory, we will know that the top region of the beam will be equally strained and this will be an axial strain. On the top, this will be the x-axis strain and I need to view the 11-direction strain. However at the sides of the beam, I will have to view the 33-direction strain in order to see the distribution of the strain in the top fiber of the beam. The voltage generated in the piezoelectric uses the d31 coefficient, which is poled in 3 direction and strained in 1-direction. Thus, will comsol mistake the strain at the sides for 33-direction strain instead of the correct 11-direction strain? And due to this output a wrong representation of the voltage. Since at the top section, it recognizes the axial strain as 11-direction, but the side it recognizes the strain as 33-direction. I would expect an equal distribution of voltage from outer thickness to inner thickness of the u-shape beam. But the voltage output that I'm getting follows the distribution of the 11-direction strain plot that only shows the correct distribution at the top region. Thanks. I can provide the plots if needed.

Regards,
Lionel