Tortoise-back-reinforced elliptical-embedded honeycomb composite structure: experimental and numerical analysis of responses under blast loading

Honeycomb composite structures have attracted extensive attention in protective engineering due to high specific energy absorption and strength-to-weight ratios. However, conventional honeycomb composite structures have difficulty meeting modern protective requirements. This study innovatively introduces a biomimetic tortoise-back and tendon structure to design a Tortoise-back-reinforced Elliptical-embedded Honeycomb Composite Structure (TEHS), investigating its dynamic responses and energy absorption characteristics under blast loading. Results indicate that the TEHS primarily exhibits localized large-deformation damage under blast loading, with energy absorption concentrated in both local deformation and global response stages. Parametric analysis reveals that cell length, cell wall thickness, and number of layers significantly influence the overall energy absorption capacity, meanwhile core height ratio has negligible impact on total energy absorption but drastically alters energy distribution patterns among structural components. Through analyzing dynamic yielding and response mechanisms, a mathematical model for predicting residual deflection under blast loading was established, which accurately predicts the final structural deformations.