Optimization Design and Compressive Mechanical Behavior of Derivative Body-Centered Cubic Lattice Materials

By adding vertical rods at periphery and at periphery and center of the traditional body-centered cubic (BCC) lattice structure（H0 type）, the H1 and H2 type derivative BCC lattice structures were designed. The lattice samples with different size parameters were prepared by laser selective melting (SLM) with AlSi10Mg alloy powder as raw materials. The compressive mechanical behaviors of samples were studied. The results show that the traditional and derivative BCC lattice samples were all stretching-oriented porous materials, whose compression behaviors could be divided into three stages: linear elastic stage, plateau stage and densification stage. With the same structural parameters, the specific strength, platform stress and energy absorption per unit mass of H2 type BCC lattice sample were the largest, followed by those of H1 type, and those of H0 type were the smallest. With the increase of cell height, the specific strength and energy absorption per unit mass of H1 type lattice samples were basically unchanged, the fluctuation of the platform stress increased slightly, and the energy absorption efficiency decreased slightly. With the increase of cell width, the specific strength, platform stress and energy absorption per unit mass of H1 type lattice samples decreased obviously, and the energy absorption efficiency remained unchanged. With the increase of diameter of inclined and peripheral vertical rod, the specific strength, platform stress and energy absorption per unit mass of H1 type lattice samples increased obviously, and the energy absorption efficiency increased first and then became stable. With the increase of diameter of central vertical bar, the specific strength, platform stress, energy absorption per unit mass and energy absorption efficiency of the H2 type lattice samples increased. The deformation mode of the derivative lattice sample was mainly layer by layer deformation from bottom to top, and the damage mechanism was lateral bending of the vertical rod and vertical bending of the inclined rod.