消除电阻应变片大应变测量计算误差的算法研究

Algorithm Study of Eliminating Calculation Errors in Large Strain Measurement With Strain Gauges

利用电阻应变片进行应变测量,特别在大应变测量时,测试电路输出电压与应变片应变并不是简单的线性关系。为减少或消除计算误差,提出按测试电路输出电压与应变片应变的非线性关系进行精确计算应变值,并提出了相应的改进算法应变计算公式,在单臂应变计感受应变测量场合,对大应变和小应变测量均适用,无计算误差,并得到了实验论证。同时提出了考虑应变片灵敏度系数修正和长导线电阻修正的改进算法应变计算公式,非常容易通过软件实现,可广泛应用于科学实验和工程测量。

There is no simple linear relationship between the gauge＇s strain and the circuit voltage output in strain measurement with strain gauges, especially in large strain measurement. In this paper, a modified algorithm is proposed to improve the accuracy of strain obtained from the voltage output measurement. The strain is calculated from a nonlinear relationship between the voltage and the strain rather than a linear simplification. The proposed method of strain calculation is suitable for both large and small strain measurements using a quarter bridge, and is validated by experimental tests. Moreover, the corrections of different sensitivity factors of strain gauges and the lead wire resistance are considered. It is also very easy to implement as a software form and widely used in scientific tests and engineering applications.