Experimental investigation of non-linear constitutive behavior of PZT piezoceramics
Experimental investigation of non-linear constitutive behavior of PZT piezoceramics
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PZT压电陶瓷非线性本构行为的实验研究
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Dayu Zhou
中科院分区：
文献类型：
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作者：
Dayu Zhou
实验研究了PIC151软PZT陶瓷在纯电场、纯压应力和机电联合加载条件下的单轴非线性大信号行为。在纯循环电场载荷下，观察到了极化和应变-电场的磁滞回线。相应的应变-极化(S-P)曲线也表现出明显的滞后。材料响应依赖于外加电场的加载速率和幅度。加载速率越高，矫顽场越小。在去除电场载荷后，老化效应导致残余极化和应变随时间减小。在纯压应力作用下，材料表现出非线性的应力-应变行为。此外，对于预极化样品，观察到了一条非线性的退极化曲线。通过随后施加电场使材料重新极化，可以使机械载荷引起的极化和应变的永久性变化恢复到它们的初始值。加载速率对材料的非线性应力-应变行为也有影响。当承受恒定载荷时，这种材料表现出显著的时间依赖效应。随着外部载荷保持时间的推移，极化和应变表现出蠕变行为。当载荷接近矫顽场或矫顽应力时，观察到最显著的时间依赖效应。在不同水平的预加载压应力下，测量了极化和应变对电场的磁滞回线。结果表明，叠加压缩载荷降低了材料的剩余极化，降低了矫顽场，并对材料的介电性能和压电性能产生了显著影响。高场介电常数和压电系数在较小范围内随压缩预紧力的增加而增大。性能的改善伴随着不利的较大滞后，这归因于更大的外部贡献，这是由于预应力引起了更多的非180°域切换。还研究了偏置电场对非线性应力应变和应力去极化响应的影响。当施加平行于预极化方向的电场时，非线性曲线被有效地闭合。启动和转发铁弹域转变需要较大的应力。当样品受到与预极化方向反平行的偏置电场时，这一趋势发生了逆转。
The uni-axial non-linear large signal behavior of PIC 151 soft PZT ceramics was experimentally investigated under a pure electric field, a pure compressive stress and combined electromechanical loading conditions, respectively. Polarisation and strain vs. E field hysteresis loops were observed under a pure cyclic electric field load. The corresponding strain vs. polarisation (S - P) curves also exhibited a significant hysteresis. The material response was found to depend on the loading rate and amplitude of the applied E field. A higher loading rate resulted in a smaller coercive field. Ageing effects caused the remnant polarisation and strain to decrease with time after removing the E field load. As subjected to a pure compressive stress load, the material exhibited non-linear stress-strain behavior. In addition, a non-linear depolarisation curve was observed for the pre-poled specimen. Permanent changes of polarisation and strain induced by the mechanical load could be brought back to their initial values by a subsequent application of an electric field to repolarise the material. Loading rate dependence was also found in the non-linear stress - strain behavior. When being subjected to a constant load, this material exhibited significant time-dependent effects. Polarisation and strain exhibited creep-like behavior with the passage of the external load hold time. Most pronounced time-dependent effects were observed as the load was close to the coercive field or the coercive stress. Polarisation and strain versus electric field hysteresis loops were measured under various levels of a preload compressive stress. It turned out that the superimposed compression load reduced the remnant polarisation, decreased the coercive field and also had a significant impact on the dielectric and piezoelectric properties. High field dielectric permittivity and piezoelectric coefficients were found to be enhanced by the compressive preload within a small range. The improved performance was accompanied by an unfavorable larger hysteresis, which was attributed to larger extrinsic contribution due to more non-180° domain switching induced by the prestress. The effects of a bias electric field on the non-linear stress - strain and stress - depolarisation response were also studied. The non-linear curves were effectively closed upon application of an electric field parallel to the pre-poling direction. Larger stresses were needed to initiate and forward the ferroelastic domain switching. The inverse of this trend occurred when the specimen was subjected to a bias electric field anti-parallel to the pre-poling direction.