拉铆钉螺杆应力测试误差分析及修正

Error analyses and correction in testing threaded rod stress of blind rivet

使用金属应变式传感器和压阻式压力传感器进行拉铆钉常温铆固,以及-50℃～70℃温度范围内钢质螺杆的轴向应力测试,两种测试结果存在一定差异。分析两种方法得到的测试数据,指出因零点输出的影响,压阻式压力传感器测得的预紧力存在误差;由于测试方法的不足和温度误差的影响,应变式传感器测得的温度应力存在误差。使用串并联补偿电路和双丝半桥式温度自补偿应变计可有效修正这些误差。

There are some differences between the preload results of blind rivets tested at room temperature with metal strain film sensor and piezoresistive pressure sensor,and between the axial stress results of the steel threaded rod tested in the temperature range of-50℃ to 70℃ with the above two sensors.This paper analyzes those test data.And the analyses results show there are some errors when testing preload with piezoresistive pressure sensor,which may be due to the influences of zero output;and there are some errors when testing temperature stress by metal strain film sensor,which may due to the shortage of the measurement methods and temperature errors.Finally,the authors proposed to correct these errors by using the series parallel compensation circuit and the self-temperature-compensated strain gauge of double wire and half bridge type,and proved the effects of the solution.