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Stress distribution and thermal environmental monitoring of structure by the use of piezoelectric and pyroelectric tape sensor

利用压电和热释电胶带传感器进行结构的应力分布和热环境监测

基本信息

批准号：
15360467
负责人：
FUJIMOTO Yukio
金额：
$ 6.59万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

Piezoelectric element PVDF film is polarized by the fluctuating strain when it is adhered on the surface of the structural member. Strain measurement is possible taking the piezoelectric constitutive law into account. Also, the PVDF film is applicable to the measurement of thermal environment by the pyroelectric property it possesses.In this research, a stress distribution measurement tape which can be used to measure the stress distribution along a specified line on the surface of structural member is mainly developed. The stress distribution measurement tape is an insulating adhesive tape on which rectangular PVDF films (5.0×2.5 mm) are repeatedly pasted with three inclination angles of 0, 45 and 90 degree to the direction of the tape length. Due to the property of piezoelectric material, each PVDF film will generates surface potential proportional to the applied strain after the tape is adhered onto a structural member. The surface potential can be measured by an electrostatic voltmeter of non-contact type. A tack-like electrode, a tack-pin electrode attached to the probe of the electrostatic voltmeter, is employed to measure the strain on the PVDF film within a small region. It plays a role to transfer the electric potential on the polarized surface of the piezoelectric element to the probe by electrostatic induction. Since there are no wiring works for each PVDF film, multi-point stress measurement can be achieved easily and conveniently. The applicability of such stress distribution measurement tape is verified through experiments on a notched specimen and a cracked specimen under constant cyclic loads. The measured distributions of σ_x, σ_y and τ_<xy> are compared with those calculated by FE analysis.

压电元件PVDF薄膜粘贴在结构件表面时，会因波动应变而发生极化。考虑到压电本构定律，可以进行应变测量。此外，PVDF薄膜还利用其所具有的热释电特性，适用于热环境的测量。本研究主要开发了一种应力分布测量带，可用于测量结构件表面沿指定线的应力分布。应力分布测量带为绝缘胶带，其上重复粘贴矩形PVDF膜(5.0×2.5mm)，与带长方向呈0度、45度和90度三种倾斜角。由于压电材料的特性，在将胶带粘附到结构件上后，每个 PVDF 薄膜都会产生与所施加的应变成比例的表面电势。表面电位可以通过非接触式静电电压计来测量。采用粘性电极（即附着在静电电压计探头上的粘针电极）来测量小区域内 PVDF 薄膜上的应变。它的作用是通过静电感应将压电元件极化表面上的电势传递给探头。由于每个PVDF薄膜无需布线，因此可以轻松方便地实现多点应力测量。通过恒循环载荷下缺口试件和裂纹试件的实验验证了该应力分布测量带的适用性。将测量的 σ_x、σ_y 和 τ_<xy> 分布与有限元分析计算的分布进行比较。