Identification of material parameters in Timoshenko frames

The dynamic stiffness method and the Wittrick–Williams algorithm have been used herein to evaluate the natural frequencies of a Timoshenko frame. It is possible to represent with a surface the dependance of each frequency on the structure’s material parameters (Young’s and tangential moduli of elasticity), if they are assumed as continuous variables. Inversely, when given values of the frequencies are considered, for example from experimental tests, the frequency surfaces allow us to determine curves which cross at one point. This enables a proper identification of the material parameters and further updating of the structural model.