Abstract
Piezoelectric film is a sensing element that generates an electrical charge proportional to a change in mechanical stress. When the piezoelectric film is glued to the surface of a cracked material subjected to varying load, periodic change in distribution of electric potential is observed on the surface of piezoelectric film. Based on this phenomenon, the passive electric potential CT (computed tomography) method was developed for identifying two- and three-dimensional cracks. In the previous study, contact measurement method using electrodes and voltmeter was applied. In the present study, electric potential distribution is measured by non-contact voltmeter, which may be suitable for multi-point measurement, to develop non-contact electric potential CT measurement. It was found that the non-contact electric potential CT measurement had improved resolution and accuracy in crack identification.
