Compression behavior of FCC- and BCB-architected materials: theoretical and numerical analysis

The aim of this work is to investigate the mechanical behavior of architected materials mimicking a crystal microstructure. The initial collapse strength of the architected materials is predicted by limit analysis, and the post-collapse response is theoretically obtained, considering the elastic effect and large deformation. The unit cell of body-centered block (BCB)-architected materials is defined using two parameters: the angle \(\gamma_{0}\) between the diagonal strut of the block and horizontal plane and the angle \(\varphi\) between the diagonal and the hem of the horizontal plane. The results reveal that the initial collapse strength of the BCB under statically admissible fields is the same as that under the kinematically admissible field. The stress–strain curve of the BCB with smaller angle \(\gamma_{0}\) possesses a plateau whose value is almost the same as the initial collapse strength. The BCB with larger angle \(\gamma_{0}\) has a larger initial collapse strength; however, they exhibit a significant decline of post-collapse response during compression, which means that the transition of the deformation mechanism of BCB may occur in the angle range (35º, 40º). The stress–strain curve of the face-centered cubic (FCC)-architected materials generally features a sharp drop after a peak, without a plateau. A detailed finite simulation was carried out to verify the analytical model results.