Optimal design of the ballistic resistance for new titanium alloy composite armor based on SVR surrogate model and NSGA-II algorithm

To reduce the damage range of traditional spliced composite armor, a novel composite armor structure composed of titanium alloy faceplate, silicon carbide （SiC） ceramic, ultra-high-molecular-weight polyethylene（UHMWPE） laminate, and integrated titanium alloy lattice and back plate is proposed. And we employ optimal design of the structure to achieve the enhancement of the ballistic resistance and weight reduction.

Comparative studies on the ballistic resistance of the novel composite armor is conducted by numerical methods. A high-accuracy surrogate model is established to rapidly predict the ballistic performance of the composite armor, and correlation analysis is performed between structural parameters and residual velocity and areal density. The structural parameters of the composite armor are optimized based on the NSGA-II multi-objective genetic optimization algorithm.

The results indicate that, compared with traditional spliced composite armor, the new composite armor reduces the residual velocity of the projectile by 11.7% and the damage range by 60.9% due to the presence of the integrated titanium alloy lattice and back plate. The damage range is confined to the inside of the grill, while the rest of the structure maintains better integrity. The anti-penetration performance of the areas with weak protection located at the splices is improved. After optimization, the residual velocity of the projectile is reduced by 21.0%, while the areal density decreases by 5.3%. The residual velocity of the projectile shows the strongest correlation with the thickness of the UHMWPE laminate and the weakest correlation with the thickness of the titanium alloy back plate. The optimized structural design scheme is as follows: the thickness of SiC ceramic is 4.25 mm, the thickness of UHMWPE laminate thickness is 10.65 mm, and the thickness of titanium alloy backplate thickness is 0.52 mm. After optimization, the residual velocity of the projectile is reduced by 21.0%, while the areal density reduced by 5.3%.

Compared with the traditional spliced composite armor, the novel composite armor structure demonstrates superior anti-penetration performance. The method for structural optimization design of composite armor based on the SVR surrogate model and NSGA-II algorithm is effective and feasible.