Characterization of low-velocity and low-energy responses of elastic-plastic plate struck by elastic-plastic impactor

This paper presents a study on the characterization of low-velocity and low-energy impact responses of elasticplastic plate struck by elastic-plastic spherical impactor. The applicability of the existing impact characterization diagram is examined firstly by intensive finite element (FE) simulations for a wide range of complicated impact situations including all three types of contact: indentation, flattening and combined flattening and indentation. The limitations of the existing diagram are found in identifying the type of impact response and predicting the maximum impact force for complicated impact situations. The effects of elastic and plastic deformations of impactor on the identification and prediction by the existing diagram are analyzed. A new linear contact law is presented according to the piecewise linear characteristics of contact stiffness observed from the intensive FE results. An extended impact characterization diagram is then proposed to characterize low-velocity and lowenergy impact responses of plate under complicated impact situations with arbitrary three contact types. The extended diagram is validated by the intensive FE simulations and experimental results. It is concluded that the extended impact characterization diagram can identify correctly the plate response type to complicated impacts and predict accurately the maximum impact force in a fast and simple way without the aid of FE models and experimental tests.