Axial crush behavior of nanoporous materials functionalized liquid-filled thin-walled tube

Nanoporous materials functionalized liquid (NMFL)-filled structures demonstrate significant potential in the field of energy absorption and cushioning. To thoroughly investigate the behavior of NMFL-filled tubes under axial loading, this study establishes an analytical model based on the ring-shaped crushing hypothesis, deriving analytical expressions for peak stress and mean crushing stress, with the accuracy of the theoretical model validated through finite element analysis. The results show that the crushing process of NMFL-filled tubes exhibits three distinct stages: elastic, yield, and strengthening. For a representative configuration, the FE-predicted peak stress and mean crushing stress in the yield stage are 20.94 MPa and 16.00 MPa, respectively, while the corresponding theoretical predictions are 23.68 MPa and 16.99 MPa. Parametric analysis reveals that the infiltration pressure of the NMFL and the wall thickness of the tube are key parameters controlling the crushing morphology, and global buckling instability occurs when the infiltration pressure exceeds 14 MPa. This study fills the gap in the theoretical modeling of axial crushing for NMFL-filled structures and provides a scientific basis for developing new high-performance cushioning and energy-absorbing materials.