RECOVERABLE ENERGY ABSORPTION AND DAMAGE TOLERANCE OF SPHERICAL TENSEGRITY-INSPIRED METASTRUCTURES

Failure of materials and structures is often initiated by localized deformation, such as shear-band formation, crack propagation, or the global collapse of space trusses triggered by the buckling of individual struts. In lightweight structures, such localized mechanisms can lead to abrupt loss of load-bearing capacity and catastrophic failure, thereby limiting their use in large-deformation energy absorption and reusable protection scenarios. In this study, a spherical tensegrity-inspired metastructure is proposed to enhance recoverable energy absorption and damage tolerance by inducing nonlocal cooperative deformation through discrete compression loops and multi-path load-transfer networks. Through 3D printing, quasi-static compression, cyclic loading, free-fall ball impact experiments, and finite element simulations, we show that the proposed topology accommodates large compressive deformation primarily through strut bending, torsion, node rotation, and configurational rearrangement, thereby suppressing localized collapse and instability propagation. Compared with the unit-cell structure, the multi-cell structure increases the peak force, absorbed energy, and specific energy absorption by approximately 11.2, 11.9, and 12.4 times, respectively, while improving the energy absorption efficiency from 66.2% to 73.1%. Under cyclic compression at strain levels ranging from 10% to 30%, the structure exhibited stable hysteretic responses after 10 loading–unloading cycles at each strain level, with no obvious stiffness degradation or irreversible failure, demonstrating good recoverable energy dissipation capability. Local damage in thin rod, thick rod, and dual rod reduces the specific energy absorption to 77.7%, 62.8%, and 38.8% of the undamaged value, respectively, yet no global collapse occurs. Ball impact tests further confirm that damaged structures prolong the impact response and reduce rebound kinetic energy while retaining structural integrity. Compared with typical truss architectures, the spherical tensegrity-inspired metastructure exhibits higher energy absorption efficiency and superior elastic recovery. These results demonstrate that delocalized deformation enabled by discrete compression loops and multi-path load transfer provides an effective architectural strategy for lightweight, reusable, and damage-tolerant protective systems.