A non-linear Ritz method for the analysis of low velocity impact induced dynamics in variable angle tow composite laminates

Variable angle tow (VAT) laminates feature composite layers reinforced by fibres following continuous curved paths and offer a wide structural design space for the manufacturing of composite components. In this work, a formulation for the analysis of the impact-induced dynamics in VAT laminated plates is proposed, implemented and tested in this work. The method is based on the adoption of first order shear deformation kinematics and includes von Karman non-linear strains. The discrete system is obtained by employing a pb-2 Ritz series expansion into the Hamilton's variational statement, while the impact loading is modelled through Hertzian contact law. The resulting non-linear governing equations are solved using a Newmark time step integration algorithm, coupled with an iterative solution strategy. After validation against available literature data, several tests on different VAT configurations are performed, highlighting analogies and differences between different layups in terms of impact-induced dynamic response.