Electrical Response And Failure Analysis Of Cement Based Piezoelectric Composites Under Repeated Loading

The emergence of cement based piezoelectric composite is expected to solve the compatibility problem between traditional smart materials and concrete in online monitoring.In this paper,1-3cement based piezoelectric composite was prepared by cutting-casting method.Quasi-static uniaxial compression test,cyclic loading test,single impact compression test and repeated impact compression test were carried out on PZT-5H and 1-3 cement based piezoelectric composite using MTS810 universal material testing machine and SHPB testing device.The simulation results were analyzed by ABAQUS finite element software.Under the quasi-static loading,the stress-strain curves of PZT-5H and 1-3 cement based piezoelectric composite show obvious nonlinear characteristics.Under the cyclic loading,the output electric displacement and the applied load of PZT-5H and 1-3 cement based piezoelectric composite have a one-to-one response characteristic.And by observing the static sensitivity calibration results of the samples,it can be found that there is a threshold G-value for the static sensitivity of the two samples.When the loading stress is no more than the G-value,the output electrical displacement of the sample has a good linearity with the stress.At the same time,the experimental study on the effects of different initial static load,cyclic amplitude and loading frequency on the mechanical-electric response characteristics of PZT-5H and composites were carried out.The test results show that the two materials have the same variation law.At the higher stress ratio,the output electrical displacement amplitude of the sample does not change significantly with the increase of cycle times.At the lower stress ratio,the output electrical displacement amplitude of the sample shows a decreasing rule with the increase of cycle times,which appears faster drops in the early stage of the loading and gradually stable changes at the later stage.Under the same stress ratio,the output electrical displacement amplitude of the sample changes in the same way with the increase of the cycle time and no related with the loading frequency.Under the impact loading,the compressive strength of the PZT-5H and 1-3 cement based piezoelectric composite increases with the increase of the strain rate,and the strain-rate effect is obvious.It means that both materials are strain-rate sensitive material.And by observing the dynamic sensitivity calibration results of the sample,it can be found that there is a threshold Gvalue for the dynamic sensitivity of the two samples.When the impact loading is no more than the G-value,there is a good linearity between the output electrical displacement and the impact loading.Under the repeated impact loading,PZT-5H have similar changes with 1-3 cement based piezoelectric composite.When the impact loading is no more than the G-value,the outputelectrical displacement of the sample does not change significantly with the increase of number of impact loading,the sample has good repeatability.When the impact loading is more than the Gvalue,the output electrical displacement of the sample and the piezoelectric performance gradually decrease with the increase of number of impact loading.The static sensitivity of PZT-5H and 1-3 cement based piezoelectric composite was numerically simulated by ABAQUS finite element software.The simulation results show that the simulated values of the two samples are close to the experimental values,The relative error of the PZT-5H is 6.1%.The relative error of the 1-3 cement based piezoelectric composite is 15.5%.