Cure monitoring of composite laminate by piezoelectric ceramics (influence of stacking sequence of composite laminate on impedance of piezoelectric ceramics)

摘要

Two types of glass fiber reinforced plastics (GFRP) laminate which have different stacking sequence are prepared. An actuator type piezoelectric ceramics is embedded in the GFRP laminates, and dielectric sensors are also embedded as reference sensors. The GFRP laminate is cured by an autoclave process. The level of electrical impedance of the piezoelectric ceramics is adopted as the cure index. The change in impedance at non-resonant frequency shows good correspondence with change in the log ion viscosity which is measured by the dielectric cure monitoring sensor. It is found that in cooling stage, the changes in the impedance of the piezoelectric ceramics depend on the stacking sequence of the GFRP laminate.