Experimental and numerical investigation of 3D printed micro-lattice structures for high energy absorption capabilities

Micro-lattice structures produced through additive manufacturing techniquesare offers exceptional combination of physical attributes such as light-weight, high compressive strength, impact resistance and energy absorption. The properties of these structures could be tailored by altering their shape. The advancement of additive manufacturing has simplified the development of micro-lattice structures and allowed to create more complex design. This paper investigates the effect of geometric change in the micro-lattice structure on the specific energy absorption. Experimental and numerical work has been performed on a body-centered-cubic (BCC) architecture. 3D continuum elements have been used to model the structure under quasi-steady compressive loads. To validate the numerical model, finite element results were compared with the experimental data. After achieving a satisfied comparison, geometric parameters study was conducted numerically to obtain the micro-lattice structure that exhibits high energy absorption characteristics. Five series of BCC lattice-structured models varying the number of unit cells and the strut diameter were generated, keeping the total mass constant. The results shows that, for same structural displacement, the structure with more unit cells collapse to solid structure whereas BCC structure with less number of unit cells has still space and could be deformed to larger displacement before reaching the solid structure state. However, this does not ascertain that larger displacement allows more energy to be absorbed. Reducing the unit cells increases the energy absorption attribute. The study shows that, for high energy absorption, an optimum diameter of the strand and number of unit cells exists.