Blast mitigation performance of sacrificial cladding with shear thickening fluid-filled origami metastructure core

In this study, a novel nature-inspired sacrificial cladding is proposed by partially filling shear thickening fluid (STF) into the unit cells of its origami metastructure (OM) internal core, mimicking the existence of viscoelastic material found in the protective mechanism in nature. The blast mitigation performances of the proposed STF-OM claddings in two groups of different unit shapes (Unit-A and B) are investigated and evaluated by comparing them with the non-filled and thick wall counterparts under various blast intensities using LS-DYNA. The peak and uniformity of transmitted pressures to the back-protected structure, maximum compressive deformation, and energy absorption are used to evaluate the blast mitigation performance of the sacrificial cladding under various blast intensities. It is observed that the filling of STF into OM (STF-OM) leads to lower and more uniform transmitted pressures to the protected structure compared to the non-filled OM (E-OM), and the OM with thicker wall thickness (E-OMT), as well as the conventional aluminium foam and square honeycomb claddings with the same overall mass, particularly under high blast load. As the blast load intensifies, STF-OM cladding exhibits enhanced energy absorption while still maintaining a lower and more uniform transmitted pressure, without experiencing excessive deformation, thereby highlighting its excellent blast mitigation performance and adaptive energy absorption capability. The core wall thickness, filling location of STF, and core thickness also significantly affect the blast mitigation performance and deformation of the proposed STF-OM cladding. It is found that improving cladding performance by increasing the core wall thickness is not consistently favourable, as it increases both the mass of the protective structure and the transmitted initial peak force. In contrast, by partial filling with STF, the internal OM core can still deform to absorb energy and squeeze the STF during deformation, allowing the blast energy to be absorbed through both plastic deformation of the internal core and viscous dissipation of the STF. • New shear thickening fluid-filled origami metastructure (STF-OM) cladding is proposed. • Blast mitigation performance of STF-OM cladding is revealed. • Excellent and adaptive blast mitigation performance is achieved. • Effects of wall thickness, core thickness, and filling configuration on performance are examined.