Department of Applied Physics and Electronics and the Centre for Biomedical Engineering and Physics, Umea University, Umea, Sweden.
IEEE Trans Ultrason Ferroelectr Freq Control. 2013 Jan;60(1):243-55. doi: 10.1109/TUFFC.2013.2555.
To gain an understanding of the electroelastic properties of tactile piezoelectric sensors used in the characterization of soft tissue, the frequency-dependent electric impedance response of thick piezoelectric disks has been calculated using finite element modeling. To fit the calculated to the measured response, a new method was developed using harmonic overtones for tuning of the calculated effective elastic, piezoelectric, and dielectric parameters. To validate the results, the impedance responses of 10 piezoelectric disks with diameter-to-thickness ratios of 20, 6, and 2 have been measured from 10 kHz to 5 MHz. A two-dimensional, general purpose finite element partial differential equation solver with adaptive meshing capability run in the frequency-stepped mode, was used. The equations and boundary conditions used by the solver are presented. Calculated and measured impedance responses are presented, and resonance frequencies have been compared in detail. The comparison shows excellent agreement, with average relative differences in frequency of 0.27%, 0.19%, and 0.54% for the samples with diameter-to-thickness ratios of 20, 6, and 2, respectively. The method of tuning the effective elastic, piezoelectric, and dielectric parameters is an important step toward a finite element model that describes the properties of tactile sensors in detail.
为了了解用于软组织特性表征的触觉压电传感器的机电弹性性能，使用有限元建模计算了厚压电盘的频率相关电阻抗响应。为了使计算响应与测量响应相匹配，开发了一种新方法，该方法使用谐波泛音来调整计算的有效弹性、压电和介电参数。为了验证结果，从 10 kHz 到 5 MHz 测量了直径与厚度比为 20、6 和 2 的 10 个压电盘的阻抗响应。使用具有自适应网格功能的二维通用有限元偏微分方程求解器以频率步进模式运行。本文介绍了求解器使用的方程和边界条件。给出了计算和测量的阻抗响应，并详细比较了共振频率。比较结果表明，直径与厚度比分别为 20、6 和 2 的样品的频率平均相对差异分别为 0.27%、0.19%和 0.54%，具有极好的一致性。调整有效弹性、压电和介电参数的方法是实现详细描述触觉传感器特性的有限元模型的重要步骤。
