Energy absorption characteristics of novel bionic H-type whip restraints for nuclear power plants

To enhance the efficiency of energy absorption in H-type whip restraints for nuclear power plants, this study takes inspiration from the asymmetric twisted lines observed in the Nautilus shell, introducing the Nautilus Bionic Hierarchical Multi-Cell (NBHMC) structure. For different high-energy pipeline sizes and energy absorption quantities, the proposed structures are miniaturized and can be combined into H-type whip restraint by multiple tubes to meet the requirements. The NBHMC structures are investigated based on the validated finite element method, the results demonstrate that the energy absorption per unit mass of the new structure can reach up to 180% of that of the hollow tube, with the maximum enhancement in energy absorption efficiency being 47%. Through parameter analysis of the cross-sectional wall thickness, the highest energy absorption efficiency obtained is 99.62%, with a specific energy absorption of 31.29J/g. Furthermore, utilizing the TOPSIS method, all proposed parameter combinations are ranked, leading to the determination of the optimal parameter combination. Additionally, a theoretical model predicting the mean crushing force is introduced, exhibiting good agreement with numerical simulations. The results presented in this work provide innovative insights for the design of efficient pipe whip restraints.