A method is presented to calculate the depth of the permanent indentation of laminates after low-velocity impact. It is based on the Hertzian contact law
and uses the finite element simulation results of the low-velocity impact. Two typical materials
T700/5428 and T300/5428
are analyzed and a comparison of the contact force history and permanent indentation between the calculations and impact test results is given which shows the feasibility and effectiveness of this method in the case of small damage. The method can provide a reference to predict the performance of the composite.