四点简支等弯矩梁装置对应变计标定精度影响

Influence of strain gages calibration accuracy with four-point simple supported curved beam device

通过理论分析,分别从加载摩擦力、试验梁尺寸变化和温度变化着手,进行误差计算,四点式简支等弯梁标准应变的不确定度达到18.63%,严重影响应变计性能的标定精度,不符合电阻应变计国家标准和OIML国际R No.62号建议要求。通过对比分析,高精度SK-1A钢架梁结构可以将误差降低,实现标准应变相对误差仅0.054%,高温下也只有1.2%,有效解决应变计标定精度,实际测试结果也进一步验证该结论。

Through theoretical analysis,starting from the loading friction force,the change of the test beam size and the temperature change,the error calculation is carried out.The uncertainty to the standard strain of four-point simple supported iso-curved beam reaches 18.63%.It seriously affects the calibration accuracy of strain gage and does not meet the national standard of resistance strain gage and OIML international R No.62.Through contrastive analysis,the high-precision SK-1A steel frame beam structure can achieve the standard strain relative error of 0.054%and the accuracy of 1.2%at high temperature,which can effectively solve the calibration accuracy of strain gage.The actual test results also verify that conclusion.