In order to better meet the load-bearing and ballistic performance for the protective structures of key compartments of ships

a staggered composite armor composed of polyurea-coated ceramic

UHMWPE(Ultra-high molecular weight polyethylene) laminates and grid sandwich core was proposed. The damage characteristics under different projectile impact velocities were analyzed

and the structural optimization was carried out. A numerical model for the ballistic response of the staggered composite armor structure was constructed

and a surrogate model for the ballistic resistance of the stacked composite armor was established and tested. Then correlation analyses were conducted among structural design parameters

residual velocity

and areal density. Finally

the structural parameters of the composite armor are optimized based on the NSGA-II（Non-dominated Sorting Genetic Algorithm） multi-objective genetic optimization algorithm. The ballistic limit velocity exhibited the strongest correlation with ceramic layer thickness

while areal density was most sensitive to the thickness of the sandwich face panels. Compared to the initial design

the optimized design can increase the ballistic limit velocity by 24.1% under the same areal density

or reduce the areal density by 19.8% under the same ballistic limit velocity. The proposed methodology integrating Kriging surrogate model and NSGA-II algorithm is feasible for optimization of stacked composite armor. The findings provide practical insights for structural optimization of composite armor.