A novel piezoelectric dynamometer based on double-sensor for thermal compensation

作者:Tian, Yu; Zhang, Jun*; Ren, Zong-jin; Liu, Wei; Jia, Zhenyuan; Qi, Yazhou
来源:Proceedings of the Institution of Mechanical Engineers - Part C: Journal of Mechanical Engineering Science , 2017, 231(23): 4479-4491.
DOI:10.1177/0954406216668551

摘要

A piezoelectric dynamometer can produce thermal forces because of temperature fluctuations, thus affecting measurement precision. To investigate the influence of the thermal force on the dynamometer, this article proposes a hypothesis of decreasing the conduction power and establishes the function of a thermal force over time in an ordinary dynamometer based on the heat conduction differential equation. A novel double-sensor thermal compensation dynamometer is designed, with static calibration in constant temperature and force/heat coupling experiments, to solve the problem of the thermal force. The experimental results indicate that the nonlinearity and repeatability of the double-sensor thermal compensation dynamometer are less than 1% full scale (FS) of the static calibration at a constant temperature; in the force/heat coupling experiments, at a heating rate of 0.4?/s to 110? with a loading force of 500N, the maximal output deviation is less than 1.06% (FS), realizing the unidirectional thermal force compensation of the structure. The double-sensor thermal compensation dynamometer can be utilized in sharp temperature fluctuations environment, like rocket engine forces measurement.