Non-stationary load measurement using six-component strain-gauge balances

Abstract

A novel method using six-component strain-gauge balances has been proposed to solve an important mechanics problem in aircraft model wind tunnel testing – measuring the non-stationary force and moment vectors. A physical model is at the method’s core: the sensitive elements of each balance component are replaced by damped springs. This model measures arbitrary non-stationary loads over the entire frequency range of the balance, including the natural frequency. The problem is solved for the general case of a non-inertial balance coordinate system. The standard deviation of the proposed method for measuring non-stationary loads did not exceed 2.8%. The proposed method solves a second problem – measuring object mass and the positions of its centre of mass and moments of inertia with respect to three mutually perpendicular axes. The method is experimentally verified. An estimation of the frequency range of the strain-gauge balance for measuring non-stationary loads was made using the developed method.