Mechanical properties of BCC lattice cells with waved struts

In this paper, the mechanical properties of a modified Body-Centred Cubic lattice cell with waved struts have been determined using FEM simulations with solid element mesh. The strut waviness introduces orthotropic properties in the cell and the correlation between geometrical cell parameters and resulting mechanical attitudes is calculated. For a complete determination of all the mechanical constants, uniaxial compression and in-plane shear have been simulated along different loading directions. Attention has been particularly paid to the definition of appropriate boundary constraints able to mimic the periodic condition that applies to a repetitive unit cell. At first, the numerical model has been validated with existing analytical and experimental results available in the literature, then parametric strut waviness has been introduced to this model. A systematic numerical study has been conducted on lattice cells with different density and different wave amplitude. Results have evidenced for the waved struts a considerable increase in the longitudinal uniaxial modulus and a negligible effect on the transverse moduli, while a slight reduction of the shear moduli is generally obtained in all the sliding planes. Poisson's ratios are highly affected both by density and waviness. The obtained results can be useful for the optimized definition of a lattice cell, tailored to the specific mechanical requirements of an advanced component.