Saturated impulse for pulse-loaded rectangular plates with various boundary conditions

摘要

Saturated impulse refers to the critical value after which the deflection of the beam or plate under pulse loading will not increase with further applied load. This paper investigates this phenomenon for rectangular plates under rectangular pulse-loading with various symmetric boundary conditions, e.g. two opposite edges of the plate are fully clamped while the other two edges are simply supported or free. For rectangular plates with symmetric boundaries under rectangular pressure pulse, the saturated duration and saturated impulse are merely dictated by the deformation mechanism, not by the boundary conditions. Then the effects of the aspect ratio and the boundary condition on the saturation impulse for elastic-plastic plates are revealed through numerical simulation. Bilinear elastic-plastic rectangular plates, with fully clamped boundaries and simply supported boundaries, subjected to rectangular pulse-loading are taken as typical examples. Subsequently, the saturation phenomenon is summarized from square plates to rectangular plates. The correlation is made between the results obtained from elastic-plastic analysis and those predicted by the rigid-plastic approximation. Finally, based on numerical simulation, theoretically and practically meaningful empirical expressions on the saturation phenomenon are proposed to facilitate engineering designs.