Analysis and test verification of influencing factors of strain balance force measurement

Abstract

As an important component of wind tunnel force test, strain balance is very important to ensure its measuring accuracy.The operation mode of continuous wind tunnel will lead to the existence of temperature gradient in strain balance, which will generate thermal stress inside and affect the accuracy of wind tunnel test data.Starting from the actual work, this paper selects a strain balance as the research object, defines four commonly used material properties, uses ANSYS workbench to do finite element simulation, uses orthogonal test method to analyze the influence of each material parameter on the thermal strain output of the balance, and finds out the best material.At the same time, the strain balance prepared by the best material was verified by wind tunnel test.The finite element analysis results show that the influence of each material parameter on the thermal strain output of the balance is hot wire expansion coefficient, elastic modulus, specific heat capacity, density and thermal conductivity.The strain balance prepared with material 1 can effectively reduce the heat output of the balance.The experimental verification shows that the output potential signals of each element of the strain balance prepared with material 1 are relatively stable in the face of drastic temperature rise changes of the balance body and large temperature gradient, and meet the advanced standard of the national military standard.