摘要
传统应变测量方法在小量程气动力测量方面存在灵敏度不高的问题。针对此现象,从单分量入手,设计以位移测量法为基础的悬臂梁天平。以3台悬臂梁天平为例:1台传统应变天平,2台不同槽深的新型位移天平,分别进行静态校准试验及有限元仿真。将光纤应变计应用于1mm槽深位移天平,进行准度计算;将光纤、电阻2种应变计同时粘贴在传统应变天平及2mm槽深位移天平,进行2种应变计及2种测量方法的性能对比。由试验结果可知:试验中1mm槽深位移天平准度为0.02%;2mm槽深位移天平位移法测量灵敏度相比传统测量方法提高3倍;2mm槽深位移天平灵敏度为1mm槽深天平的1.57倍,但准度有所下降。本研究为小量程气动载荷的测量提供新思路。
The sensitivity of traditional measurement of small scope aerodynamic force is not very high.Aiming at this problem,this paper introduces a new measurement method：Displacement measurement method.It means setting two grooves at the same place as where the traditional gauges are pasted,then measuring the displacement of the grooves as it changs when the grooves are loaded to get the balance formula.Here take three kinds of single component balances as an example：One traditional strain balance and two kinds of the displacement balances with different grooves.The traditional balance and the displacement balance with 2mm grooves are pasted with two kinds of strain gauges,which are the optical fiber strain gauge and the strain gauge respectively,to compare the performance of both the gauges and the measurement methods.And an optical fiber strain gauge is used in the displacement balance with 1mm grooves to compare the different sensitivity caused by different depths of the grooves.The static calibration test and the finite element simulation are carried out,and we can draw conclusions as follows：The new measurement method can improve the sensitivity compared to the traditional methods,and the deeper the groove is,the higher the sensitivity becomes.For example,the sensitivity of the new balance with 2mm deep grooves is improved by 3times compared to the traditional strain balance,1.57 times compared to the 1mm deep grooves.The accuracy of the new balance with 1mm deep grooves is 0.02%,meeting the accuracy requirements.The accuracy of the balance with 2mm deep grooves is 0.09%.It thus shows that increasing the depth of the grooves would lower the accuracy,which may be caused by the decrease of the rigidity of the balance.Therefore the size of the grooves should be chosen carefully.This paper provides a new idea for small scope aerodynamic force measurement.
出处
《实验流体力学》
CAS
CSCD
北大核心
2015年第1期83-86,91,共5页
Journal of Experiments in Fluid Mechanics
关键词
位移法
单分量天平
光纤应变计
灵敏度
小量程气动力
displacement measurement method
single component balance
optical fiber strain gauge
sensitivity
small scope aerodynamic force
