Abstract
Finite element study was conducted on porous cement-based 0-3 piezocomposite materials to calculate their effective properties and predict their sensing capabilities. Piezoelectric materials used are Li-0.03(K0.48Na0.52)(0.97)(Nb0.8Ta0.2)O-3 (KNNLT), BaTiO3 (BT), Pb[ZrxTi1 - x]O-3 (PZT-5A) and Pb(Zn1/3Nb2/3)O-3-(6 - 7% )PbTiO3(PZN - PT). Effective elastic and piezoelectric properties of the porous cement-based piezocomposites were calculated using representative volume element approach along with suitable boundary conditions. Pores in the cement matrix are modelled as air inclusions. The elastic and piezoelectric properties were found to increase with an increase in the volume fraction of the piezoelectric material within the cement matrix. On the other hand, these properties were found to decrease with an increase in volume fraction of pores within the cement matrix. The calculated effective properties data were used to analyse the possible use of this materials for sensing application. Maximum sensing voltage was obtained at natural frequency of vibration of the structure. PZT - 5A demonstrated maximum voltage of 165 V at 0% porosity and 15% inclusion by volume fraction. For the remaining material, the maximum sensing voltage was found to be around 50% of the maximum voltage obtained from PZT - 5A. Maximum sensing voltage increased with an increase in volume fraction of piezoelectric inclusion and decreased with an increase in volume fraction of the pores. Maximum percentage drop in voltage was observed in PZN - PT at all inclusion volume fraction. PZT - 5A demonstrated least percentage drop in voltage with porosity at different inclusions. KNNLT and BaTiO3 demonstrated about 6.5% and 5% drop in voltage with porosity at 15% piezoelectric inclusion by volume fraction. At other inclusion volume fractions, the drop in voltage was found to be negligible.