Study on anti-explosion performance and mechanism of lattice sandwich panels of Ti-6Al-4V alloy

The ultimate goal and a challenge of anti-explosion structural design is to achieve excellent anti-explosion performance with a limited areal density. Lattice sandwich panels were designed to meet the current era's demand of anti-explosion structures. Lattice sandwich panels, well known for their lightweight, high strength, and exceptional energy absorption capabilities, have shown considerable promise in anti-explosion applications. Compared with steel lattice, this study fabricated BCC lattice material of Ti-6Al-4 V (TC4) alloy with varying layers by laser powder bed fusion technology. These cores were then consolidated with TC4 alloy plates in an autoclave. A combination of air explosion experiment and numerical simulations under the load of 200 g TNT/40 mm stand-off distance was employed to investigate the anti-explosion performance of single layer solid panel, three layers solid panel and lattice sandwich panel with similar areal densities, by evaluating anti-convex deformation coefficient, clipping rate and energy dissipation. The results showed that the anti-explosion performance of the lattice sandwich structure was the best, while the anti-explosion performance of the single layer TC4 plate was the worst. Under the same areal density, as the number of layers in the lattice cores increases, the anti-explosion performance of the sandwich panel improves. The energy dissipation of the face panel and core exceeds 79 % of the total energy dissipation of the sandwich panel, indicating that the high energy consuming lattice cores and structural layering contribute to the improvement of the anti-explosion performance of the structure. The overall failure modes of different lattice sandwich panels are similar, the densification degree gradually decreases from the center to the boundary, and the core material mainly undergoes shear fracture at the connection between the rods.