Determination of Material Parameters of FRP Plates With Rotational Flexibility at Boundaries Using Experimental Modal Testing and Model Updating

Inverse identification of material properties of Fiber Reinforced Plastics (FRP) composite plates from the experimental modal testing using finite element model updating is an active area of research. In this approach, measured dynamic responses are correlated with finite element predictions to estimate the material property parameters using optimization techniques. The current practice of modal testing advocates the free-free boundary conditions, as clamped or simply supported boundaries are difficult to realise in experiments. This restricts the application of this technique to small scale specimens, whereas there are plenty of structural applications of FRP with clamped or elastically supported boundary conditions. To extend the application of the existing technique for material parameter estimation, partial fixity at boundaries should also be taken as parameters. The present experimental study estimates varying rotational elastic boundary restraints of a rectangular FRP plate to correctly identify the in-plane material constants which otherwise would be grossly misleading.