Yield surfaces and micro-failure mechanism of block lattice truss materials

The stiffness and the strength of block lattice truss materials were derived, as well as polyhedrical yield surfaces. Tension yield, compression yield and compression buckling of struts are the three main micro-failure mechanisms of the lattice materials. It is shown that when the relative density of the lattice is smaller than a critical value micro compression buckling of struts will dominate the macro failure mode of the material under macro shearing loading or even macro tensile loading. The lattice truss materials may be optimal designed according to their stacking mode of struts and the critical relative density.