Structure Design and Energy Absorption Mechanism of a New Type of Armor Inspired from Armadillos

Dermal armor, such as fish scales or armadillo osteoderms, has been known to exhibit high performance and good flexibility defending against attack. The top layer of the dermal armor usually consists of a segmented hard bony layer. The soft inner layer composed of collagen fibers connects and holds the hard layer. Inspired by the dermal armor of armadillos, bioinspired protection armor is studied for impact resistance. The hexagonal scales tessellate the surface continuously and work as the hard bony layer protecting the soft inner layer from penetration. Ultra-high molecular weight polyethylene (UHMWPE) is used as the connectivity layer to support and hold the scales. To investigate the dynamic response of the bioinspired protection armor, drop weight impact tests are carried out. A finite element model is established to study the dynamic response of bioinspired protection armor. The impact process images captured by a high speed camera and the experimental data of drop hammer acceleration tests verify the validity of the numerical model. The dynamic resistance behavior and the synergy effect of each part of the bioinspired protection armor combined with the protected objects are studied in detail by numerical simulation. The results show that the bioinspired protection armor has marked energy absorption ability. A synergistic dissipation mechanism is activated in the impact process, which can dissipate impact energy and make the impact load distribution more uniform. The UHMWPE between the outer layer and the soft substrate plays a significant role not only related to support and connection, but also for the force balance and energy absorption. The mechanism of energy absorption of the bioinspired protection armor revealed in this paper can be taken as a new guideline for designing a novel protective armor.