The Influence of Freeze-Thaw Cycles on the Electromechanical Properties of Cement-Based Piezoelectric Composites

The electromechanical properties of 2-2 and 1-3 cement-based piezoelectric composites were experimentally studied with the same volume traction of piezoelectric ceramics after freezing and thawing at -20°C-40°C. The experimental results showed that with the increase of freeze-thaw cycles, the stress-strain curves of 2-2 and 1-3 composites gradually slowed down, the peak points decreased and the breaking strain increased. It showed that the damage caused by freeze-thaw cycles an the internal of the two kinds of samples led to the decrease of ultimate compressive strength and the increase of failure strain. The electric displacement amplitude and static sensitivity of the two composites decreased with the increase of freeze-thaw cycles. There was a critical point G in the strain-electric displacement curves of both samples. When the peak value of loading strain below point G, there was a significant linear relationship between the peak value of output electric displacement and the peak value of loading strain. Otherwise, there was a nonlinear relationship between them.