Saturated impulse for fully clamped square plates under blast loading

Abstract

Saturated impulse refers to the critical value, beyond which the deflection of a beam or plate under pulse loading will no longer increase with further applied load. The present paper investigates the saturated impulse of fully clamped square plates subjected to a blast loading that is assumed to be a uniformly distributed Linearly Rising Exponentially Decaying (LRED) pressure pulse. Considering both bending moment and membrane force, the transient dynamic plastic response is predicted by a rigid, perfectly plastic (R-PP) model characterized by travelling plastic hinge lines and time-dependent velocity field. The saturated duration, saturated impulse, saturated deflection, as well as the evolution of deformation mechanism are explored. By comparing three characteristic durations, i.e. the travelling duration of the plastic hinge lines, saturated duration and loading duration, the dynamic responses of a square plate are classified into three types such that a regime map on the loading parameters’ plane is constructed accordingly. The correlation is made between the results obtained from the elastic-plastic numerical simulation and the R-PP theoretical approximation. To facilitate engineering designs, a method of replacing the LRED pressure pulse by an equivalent rectangular pressure pulse is proposed to predict the maximum deflection of fully clamped square plates.