Enhanced energy absorption performance of hexagonal tubes by local surface nano-crystallization technique

By introducing local surface nano-crystallization, a novel strategy is proposed to controllably improve the energy absorption performance of thin-walled structures. A preliminary attempt is made to conduct the crashworthy design for hexagonal structures and several nano-crystallization design schemes are implemented. A large plastic deformation model is constructed to precisely depict the deformation mechanism of hexagonal tubes. The lateral crushing behavior and energy absorption characteristics of the untreated and nano-crystallized hexagonal tubes are investigated by the theoretical model and finite element (FE) simulation. It is found that the nano-crystallization technique can be applied to increasing the plateau force and changing deformation modes, and achieving better comprehensive energy absorption performance of hexagonal tubes. Without increasing the geometrical complexity and structural weight, the application of local nano-crystallization enhances the energy absorption abilities of existing structures and holds promising potential for designing superior energy absorbers with controllable deformation modes.