Zhao Yinming, Wang Zhigang, Tan Siyang, Liu Yang, Chen Si, Li Yongqian, Hao Qun
School of Optics and Photonics, Beijing Institute of Technology, No.5 South Zhongguancun Street, Haidian District, Beijing 100081, China.
Beijing Changcheng Institute of Metrology & Measurement, Beijing 100095, China.
Micromachines (Basel). 2022 Feb 10;13(2):280. doi: 10.3390/mi13020280.
The effect of micro-morphology of resistive strain gauges on gauge factor was investigated numerically and experimentally. Based on the observed dimensional parameters of various commercial resistive strain gauges, a modeling method had been proposed to reconstruct the rough sidewall on the sensitive grids. Both the amplitude and period of sidewall profiles are normalized by the sensitive grid width. The relative resistance change of the strain gauge model with varying sidewall profiles was calculated. The results indicate that the micro-morphology on the sidewall profile led to the deviation of the relative resistance change and the decrease in gauge factor. To verify these conclusions, two groups of the strain gauge samples with different qualities of sidewall profiles have been manufactured, and both their relative resistance changes and gauge factors were measured by a testing apparatus for strain gauge parameters. It turned out that the experimental results are also consistent with the simulations. Under the loading strain within 1000 μm/m, the average gauge factors of these two groups of samples are 2.126 and 2.106, respectively, the samples with rougher profiles have lower values in gauge factors. The reduction in the gauge factor decreases the sensitivity by 2.0%. Our work shows that the sidewall micro-morphology on sensitive grids plays a role in the change of the gauge factor. The observed phenomena help derive correction methods for strain gauge measurements and predict the measurement errors coming from the local and global reinforcement effects.
通过数值模拟和实验研究了电阻应变片微观形貌对应变片灵敏系数的影响。基于观察到的各种商用电阻应变片的尺寸参数，提出了一种在敏感栅上重建粗糙侧壁的建模方法。侧壁轮廓的幅度和周期均通过敏感栅宽度进行归一化处理。计算了具有不同侧壁轮廓的应变片模型的相对电阻变化。结果表明，侧壁轮廓上的微观形貌导致了相对电阻变化的偏差以及灵敏系数的降低。为了验证这些结论，制作了两组具有不同侧壁轮廓质量的应变片样品，并通过应变片参数测试装置测量了它们的相对电阻变化和灵敏系数。结果表明，实验结果与模拟结果也一致。在1000μm/m以内的加载应变下，这两组样品的平均灵敏系数分别为2.126和2.106，具有较粗糙轮廓的样品灵敏系数值较低。灵敏系数的降低使灵敏度降低了2.0%。我们的工作表明，敏感栅上的侧壁微观形貌在灵敏系数变化中起作用。观察到的现象有助于推导应变片测量的校正方法，并预测来自局部和整体增强效应的测量误差。
