Numerical/experimental evaluation of buckling behaviour and residual tensile strength of composite aerospace structures after low velocity impact

A procedure for the characterization of low velocity impact damage and its effect on residual tensile and buckling behaviour of composite structures is presented. A simplified analytical method is used to enhance the damage simulation and a degradation model is introduced in the subsequent finite element analysis. Different degradation coefficients are defined for three impact energy stages. Two different types of analysis are performed using MD.Nastran software: the non-linear progressive failure analysis to estimate the residual tensile strength and the linear analysis to predict the critical uniaxial and shear buckling loads after impact. Tensile and buckling experiments are used to validate the present methodology. A good correlation is obtained for all the cases under investigation.