Auxetic structure optimization for double-walled hull crashworthiness using response surface methodology

• The double arrowhead auxetic structure significantly enhances energy absorption. • Response Surface Methodology (RSM) was successfully applied to optimize geometric parameters and material selection for maximum crashworthiness. • Increasing cell arrangement and strut thickness improves structural integrity and energy dissipation, preventing localized failure. • The negative Poisson’s ratio (NPR) effect allows controlled deformation, effectively redistributing impact forces and minimizing hull damage. One type of negative Poisson's ratio (NPR) structure, called auxetic, has been widely studied due to their superior mechanical properties, including enhanced energy absorption capabilities. However, their application in marine structures, particularly in improving ship hull crashworthiness, remains underexplored. This study investigates the optimization of an auxetic structure as a filler material in the void space of a double-walled ship hull using Response Surface Methodology. The optimization process considers geometric parameters and material selection. The drop tests was conducted numerically to evaluate energy absorption performance. The results indicate that the optimized model exhibited the highest energy absorption of 2049.91 J, representing an improvement of over 2066% compared to the least efficient configuration (94.60 J), significantly outperforming other configurations. The findings provide valuable insights into the design of auxetic fillers for maritime safety applications, enhancing the structural integrity of double-walled ship hulls against high-velocity impacts.