Performance of a 3D printed cellular structure inspired by bone

Biological thin-walled cellular structures have intricate arrangements that facilitate lightweight and high energy absorption. A prime example is trabecular bone, which possesses a unique thin-walled cellular structure of connected rods or plates, to minimise weight whilst meeting the loading demands from the body. For example, the femur has a closed cell structure of plates to transmit heavy loads to the ground, whereas a carpal bone has an open cell structure of connected rods. Although existing lightweight thin-walled cellular structures with controlled arrangements have been investigated extensively, such as those with re-entrant geometries, asymmetric instability due to local buckling can hinder their energy absorption capacity. Mimicking the features of trabecular bone can offer the designer a greater degree of control over the buckling and collapse mechanisms of thin-walled cellular structures. This can lead to the development of high-performance protective systems with superior energy absorption capabilities. This study employs 3D printing and finite element analysis techniques to mimic and investigate several key features of the plate-like thin-walled cellular structure of trabecular bone. The performance of the developed bioinspired structure is benchmarked against traditional hexagonal and re-entrant designs. The controlled and progressive buckling and collapse mechanisms observed in the bioinspired structure result in superior energy absorption over its re-entrant and hexagonal counterparts.