Absorption energy of layered structures due to impact loading

In this study, the finite element formulation for the investigation of the effects of a localized interfacial delamination on the energy absorption of the [90°/0°] laminated composite plate under impact loading is conducted. The stiffness of the laminate is determined by assembling the stiffnesses of sub-elements contributed by top and bottom laminae as well as the interface under impact loading. An introduction of an interface layer with stress- and strain- influenced material description is proposed to model a more realistic interfacial delamination. Also, the kinematically consistent mass matrix and mass proportional damping are formulated to complete the transient vibration governing expression. To simulate the interfacial degeneration of the laminate, it is defined in a localized manner in accordance with the maximum stress and strain of material under study induced by impact loading. The effects of localized interface delamination on the laminated composite plates when subjected to low velocity impact loading for various energies are investigated. Generally, the central displacement and degenerated area of interface increases as the impact energy increased. In addition, the absorption energy by the interface is rises due to higher impact energy. More realistic damaged models offer greater absorption energy compared to those undamaged