Determination of axial forces by local vibration measurements

This article proposes a method to estimate the axial force in a bar based on local vibration measurements. The method assumes Timoshenko beam theory and in addition accounts for the rotational inertia of the bar and the mass of the sensors. A major advantage of the proposed method is its generality. Assuming at least five sensors along the length of the bar, no information on the connection of the bar to the adjacent nodes and so the remaining part of the structure is required. The method can therefore be used for any beam or truss element in a structure. The method is verified using finite element model simulations. A laboratory experiment is performed in order to ascertain the applicability and accuracy of the proposed method. Keywords—axial force, Timoshenko beam, boundary condition, force identification, bending stiffness