Localization and coalescence of imperfect planar FCC truss lattice metamaterials under multiaxial loadings

This study investigates the effect of stress triaxiality on failure mechanisms an-isotropic perfect and imperfect planar FCC (Face Centred Cubic) truss lattice metamaterials. Three types imperfection have been considered in numerical modelling, namely, distorted struts, missing strut diameter variation. In order to maintain constant during simulations, a novel framework was developed overcome computational difficulties within existing approaches beyond elastic region. modes microscopic localization were observed lattices before failure: crushing band, shear band void coalescence. A clear separation exists between three depending upon type level defects, as well triaxiality. Under compressive loading, all fail owing band; are prone with increase distortion, whereas majorly due coalescence at high struts defect. Strut variation, range diameters selected, shows no significant influence macroscopic mechanical response strain localization. work may open door for predicting under variety loading conditions.