Structural improvement of 3D woven honeycomb composite liner for enhanced energy absorption and impact performance in aircrew helmet

This study aims to enhance the performance of aircrew helmet liners made of 3D woven honeycomb composites through structural improvements. To achieve this, an optimization of the honeycomb design was carried out using a statistical tool by varying its geometrical parameters. A Box Behnken design was employed, using three independent factors: cell height, cell size, and cell wall thickness to assess its impact and their interactions on responses. The performance was evaluated using a multiobjective response to maximize impact energy absorption, achieve the target cushion factor, and balance relative density for lightweight design. Since the liner materials were subjected to flatwise compression and dynamic impact tests to assess the performance. Their behavior. The results revealed that the honeycomb core with a cell height of 15 mm, a cell size of 10 mm, and a cell wall thickness of 0.6 mm exhibited good behavior. The response surface analysis and contour plots were used to analyze the interactions and combined effects of variables on each response. It was observed that lesser cell size shows significant improvement in impact energy with higher wall thickness. However, the cushion factor implies inadequate energy mitigation. The analysis comparing desirability and confirmatory experiments highlighted the potential for the aircrew helmet liner to achieve its maximum performance. This study provides valuable insights into the structural design of 3D woven honeycomb composite liners for aircrew helmets and its findings signify the potential for applications in the aerospace and defense industries.