Dynamic identification of beam axial loads using one flexural mode shape

In the last decades, various methods have been proposed for the experimental evaluation of tensile forces acting in tie-beams of arches and vaults. Moreover, static and dynamic approaches have been formulated to evaluate critical compressive axial forces and flexural stiffness of end constraints. Adopting Euler-Bernoulli beam model, this paper shows that, if bending stiffness and mass per unit length of a beam with constant cross-section are known, the axial force and the flexural stiffness of the end constraints can be deduced by one vibration frequency and three components of the corresponding mode shape. Finally, data conditions are given to assess a physically admissible identification of the unknown parameters