Numerical and experimental modelling of mechanical springs made of lattice material

Additively manufactured beam-based lattice materials made of repeating unit cells are nowadays used in modern lightweight engineering design. In this paper we propose a redesign of a typical mechanical spring aiming to achieve reduced material usage by introducing a multi-scale architecture. A parametric model of the helical spring made of lattice material is developed to enable both rapid geometry and finite element preparation as well as the optimization based on differential evolution algorithm. Judicious multiscale optimization of the lattice structure together with the stress homogenization based on the lattice gradient, proved to significantly improve the spring stiffness. Experimental validation of the proposed redesign is performed on the additively manufactured spring prototypes.