Dynamic Response of Stiffened Plates under Air Blast

A numerical investigation is presented to examine the effect of stiffener configuration on the response of rectangular plate subjected to air blast loading. Dynamic response of the plate, with various stiffener layouts under air blast is analysed. The plate is modelled using shell elements and the effect of strain rates are considered using Johnson-Cook (J-C) model, under air blast load applied in the form of an equivalent rectangular uniform pulse. A modal analysis is carried out to obtain the natural frequencies of the plates that help in assessment and influence on their dynamic response. Analysis is carried out from the perspective of understanding the dynamic response of the plate, with stiffener, in comparison with equivalently thickened unstiffened plate. The results indicate that the equivalently thickened unstiffened plates exhibit higher peak displacement as compared to the stiffened plate, signifying the importance of the stiffeners placed strategically. It is concluded that the stiffener layout and strain rate consideration governs the dynamic response of the plates subjected to small duration blast loading.