Abstract
In this study, the local deformation of plates is approximated by a linear spring-mass model, and then the equivalent spring parameter is determined by an approximate method. The spring parameter is the function of the stiffness constant determined by a static solution, the initial velocity, mass of the impactor and mass of the plate. The validity and effectiveness are illustrated by numerical examples. The comparison of impact forces using proposed method and Hertz's law shows that this method yields very good results.