Design and Evaluation of Strain Gauge Force Balance with Short Test Duration

Abstract

This paper describes the design and evaluation of an aerodynamic force balance within ms-order test time. A cross-beam strain gauge force balance, which is compact and easy to extend to multi-component measurement, was developed. The balance was designed to have simple vibration characteristics with simple and high stiffness configuration. An experimental modal analysis method and finite element analysis method were applied to evaluate vibration characteristics of the balance. This balance was used for drag force measurement with a hemisphere model in a free piston shock tunnel with a test time of approximately 1 ms. A signal recovery technique based on frequency domain de-convolution, which improves time resolution of the force measurement is also described. Measured drag force coefficient agreed well with the predicted theoretical value.