A new type of composite armor, which is composed of the front steel plate, medium dual-layer piecewise ceramic tiles separated by steel grid and the Kevlar back plate, was designed based on the bio-inspiration. The failure mechanism, energy absorption, and the effect of the geometric parameters on ballistic response of composite armors were analyzed. The results show that the damage area of ceramic layer can be remarkably decreased by replacing a monolithic ceramic plate by the piecewise ceramic tiles, and the ballistic properties of armors can be enhanced by using multiple ceramic tiles separated by metal grids in composite armors.

The dynamic responses of multi-layer gradient pyramid lattice sandwich plates subjected to blast loadings were investigated by employing numerical simulation method in this paper. The relative densities of core layers were adjusted by varying cross-sectional dimensions of lattice truss. Six kinds of gradient configurations were proposed based on the arrangement of various lattice core layers. The mechanical properties of 304 stainless steel used in this analyses were simulated using rate-dependent JC constitutive model, and the blast loadings were imposed to the sandwich structures using CONWEP loading mode. The validation of the simulation approach was studied by a comparison of simulation results with the existing experimental results from the literature. The back sheet deflection and the support reaction were analyzed to evaluate the blast resistance of multi-layer gradient sandwich structures. It can be found that the gradient configuration, of which relative density of core layer increases layer by layer from front sheet to back sheet, has the most excellent blast resistance. The dynamic response of gradient lattice sandwich structures in the case of different standoff distances and different explosive charges were calculated. And the relationships between intensity of load and blast resistance of the gradient sandwich structures with pyramid lattice core were analyzed.

A multilayer gradient double-corrugated sandwich plate was designed, and the finite element method was employed to investigate numerically the dynamic responses of the sandwich plate subjected to underwater blast loads. ALE modeling method was adopted to simulate the fluid-structure interaction between the water and sandwich plate. TNT explosive was modeled by the JWL model, and the 304 stainless steel used for the double-corrugated sandwich plate was modeled by Johnson-Cook constitutive model. The peak deflection of the back face sheet, the support reaction at the edge of the sandwich plate, and the energy absorption of the structure were discussed to assess the underwater blast resistance of the double-corrugated sandwich structure. The results show that the configuration P₂ with the increasing core relative density has a better blast resistance ability and the weakest upper core layer of the configuration P₂ has the greater contribution to reducing the impulse transmission to the sandwich structure.

The anti-penetration performance of the composite armor structures, which are composed of steel, Kevlar composite, and ultra-high molecular weight polyethylene (UHMWPE) composite, were investigated numerically. The effects of composite armor configurations, the thickness of back plates, the shapes and incident angles of projectile on the anti-penetration performance were analyzed. The results indicate that the configuration with steel, Kevlar and UHMWPE on the first, second and third layers of the composite armor have the better anti-penetration performance. As the thickness of the composites back plate increases, the specific energy absorption of the composite armor decreases while the anti-penetration performance of the composite armor increases. In addition, it can be also found that the ball-headed projectile has stronger penetration ability than the flat-headed projectile of the same weight, and the penetration ability of projectile decreases with the increase in the impact angle of projectile.

This study presents a non-explosive method for simulating blast loading on reinforced concrete (RC) slabs. The method involves using a newly developed blast simulator to apply a speedy impact load on the slab, which generates a pressure wave similar to that of an actual blast. Both experimental and numerical simulations were carried out to evaluate the effectiveness of the method. The experimental results showed that the non-explosive method can produce a pressure wave with a peak pressure and duration analogous to those of an actual blast. The numerical simulations also showed good agreement with the experimental results. Additionally, parameter studies were conducted to evaluate the effects of the rubber shape, the impact velocity, the bottom thickness, and the upper thickness on the impact loading. The results indicate that pyramidal rubber is more suitable as an impact cushion for simulating blast loading than planar rubber. The impact velocity has the widest range of regulation for peak pressure and impulse. As the velocity increases from 12.76 to 23.41 m/s, the corresponding range of values for peak pressure is 6.457 to 17.108 MPa, and for impulse, it is 8.573 to 14.151 MPa∙ms. The variation in the upper thickness of the pyramidal rubber has a more positive effect on the impact load than the bottom thickness. With the upper thickness increasing from 30 mm to 130 mm, the peak pressure decreased by 59.01%, and the impulse increased by 16.64%. Meanwhile, when the bottom part’s thickness increased from 30 mm to 130 mm, the peak pressure decreased by 44.59%, and the impulse increased by 11.01%. The proposed method provides a safe and cost-effective alternative to traditional explosive methods for simulating blast loading on RC slabs.

The impact mechanical properties of graded hourglass lattice sandwich structures under impact compression were studied using experiments and numerical simulations. The influence of the gradient distribution on the deformation mode, peak load, and energy absorption capacity of the hourglass lattice sandwich structure under the same impact energy level, different impact masses, and different impact velocities is discussed. The results show that the difference in impact mass and velocity has a significant effect on the impact mechanical properties of the graded hourglass lattice sandwich structure under the same impact energy level. The gradient distribution mode is a factor that requires careful consideration in the design. A reasonable gradient distribution design can control the initial and compression peak loads to achieve similarly low values and improve the load consistency of the hourglass lattice sandwich structure. The total energy absorption of the hourglass lattice sandwich structures with different gradient distributions is the same; however, the energy absorption capacity is different at different deformation stages. When the moving distance is 0.005 m, the gradient hourglass lattice sandwich structures with the mass decline distribution can absorb 1 kJ/kg more energy than the gradient hourglass lattice sandwich structures with the mass increment distribution. When the moving distance is 0.037 m, the mass decline distribution gradient hourglass lattice sandwich structures absorb 1 kJ/kg less energy than the mass increment distribution gradient hourglass lattice sandwich structures.