应变计灵敏系数标定影响因素分析

Influence Factor Analysis for Strain Gage’s Gage Factor Calibration

灵敏系数测试的准确性影响应变式传感器的设计和输出,也会影响应变测试中的应变修正数据真实性。对砝码加载四点式简支梁结构和纯弯矩钢架梁结构灵敏系数测量模型进行分析,确定产生标准应变的影响因素。常温灵敏系数标定的影响因素有试验梁尺寸、试验梁轴向力,实际灵敏系数测试结果表明:简支梁灵敏系数略大,分散明显较大。温度下应变计的输出与载荷应变、试验梁尺寸变化、弹性模量变化等有关,明确简支梁尺寸变化、弹性模量变化受温度影响误差高达2.9%,钢架梁的刚性封闭静态力学平衡系统的温度影响误差较小。通过测试,进一步用简支梁、钢架梁实际测试灵敏系数随温度变化,验证了理论分析的正确性。

The accuracy of gage factor test affects the design and output of strain sensor as well as the au-thenticity of strain correction data in strain test.After the gage factor measuring model is analyzed which is based weights loading four points simply supported beam and pure bending steel frame beam structure,the influencing factors of standard strain will be confirmed.The influencing factors of gage factor calibration include the test beam size and the axial force of test beam.The test results of practical gage factor show that the factor of simple beam is slightly larger and the dispersion is obviously larger.The output of strain gage at temperature is related to the load strain,the size change of test beam,and the change of elastic modulus.Theoretically,the dimensional change and elastic modulus change of the simply supported beam at temperature can be caused error as high as 2.9%.The temperature influence error is very small,because the steel beam is the rigid closed static mechanical balance system.Using test,the theoretical analysis is verified by measuring the gage factor change with temperature which uses the simply supported beam and steel beam.