Reconfigurable interlocking mechanical metamaterials for tunable vibration mitigation and energy absorption

A reconfigurable mechanical metamaterial featuring topological interlocking in a modular architecture enables integrated vibration mitigation and energy absorption. This design enables adhesive-free assembly and disassembly and offers potential for repeated use. An integrated experimental and numerical investigation is conducted, combining acceleration-transmissibility measurements, compressive stress estimation, and a Bayesian optimization-Gaussian process regression (BO-GPR) surrogate model to characterize both dynamic and quasi-static mechanical responses. The results demonstrate that the metamaterial produces an elastic wave bandgap within the specific frequency range, and substantial vibration mitigation is validated by acceleration-transmissibility measurements. The bandgap characteristics are governed by the geometric parameters of the re-entrant arcs. Under cyclic compressive loading, the metamaterial retains a considerable proportion of its initial energy absorption capacity after multiple deformation cycles accompanied by substantial dimensional recovery, indicating potential for repeated use under the tested conditions. A parametric mapping relationship between the re-entrant arc geometry and the performance metrics of vibration bandgap and specific energy absorption ( SEA ) is established. The results reveal that SEA varies non-monotonically with arc length, decreasing to a minimum at a certain length before increasing markedly, whereas it generally increases with arc thickness. SEA also varies non-monotonically with arc width, exhibiting a local minimum at a particular width. A performance design framework is constructed to improve the bandgap width ( BW ) and SEA , yielding a topological parameter combination that synergistically improves both properties. This mechanical metamaterial integrates vibration mitigation and energy absorption through topological interlocking and offers a tunable design paradigm for multifunctional structural protection.