Design Optimization of Energy-Absorbing Composite Tubes in Protective Structures under Medium Field Air Blast: Insight into Efficient Design

With the increase in explosive occurrences and the development of new weapons, protective structures have received worldwide attention. The energy-absorbing core material is the most crucial part of these protective constructions. Cylindrical tube-like structures offer fascinating, effective, and beneficial features for this purpose. However, due to the nonlinear behavior, a complete knowledge of the physical process remains an open topic. Therefore, the present study uses the finite-element (FE) software LS-DYNA to examine innovatively built composite mild steel tubes under blast loading as a potential energy absorption core structure in a sacrificial system or sandwich panels. These composite designs include thin-walled taper metal tubes, cylindrical tubes, and couplers that are compressed axially between two metal plates under blast loading. Eight different designs are proposed with varying angles of taper and the inclusion of an internal cylindrical tube. The responses of composite tubes to a blast load of a medium field air burst scenario at a scaled distance of 0.401 m/kg1/3 are observed. The load transfer efficiency, along with energy absorption capacity, is examined as a function of the slope and orientation of the tubes. It has been found that the flatter slopes are more efficient in energy absorption and the reduction of transferred load in proposed designs. Moreover, the geometry and distribution of the mass in the energy absorption core also play an essential role. The provided results aid in elucidating the underlying physical principles, which in turn enables the design of protective structures that are both effective and task-specific.