Abstract：It is possible to design lattice with non-uniform cross-section in longitudinal direction using additive-manufacturing, which makes it crucial to studying the corresponding mechanical behaviors, including stiffness, strength and buckling. The longitudinal cross-section of truss is assumed to be hyperbolic or elliptic form, which effect on stiffness is calculated analytically by axial integration and that on buckling eigenvalue is deduced explicitly through introducing parameter variation in equilibrium equation. The truss with elliptic cross-section is applied in the practical pyramid lattice, and the analytical solutions are validated by eigenvalue buckling method. Moreover, the riks method is applied in calculated the post-buckling behaviors for pyramid lattice with geometric imperfection. Both analytical solution and numerical results show that the elliptic cross-section in longitudinal direction of truss can obviously improve equivalent compressive strength in condition that the stiffness is decreased slightly for pyramid lattice with low relative density. The research results provide theoretical basis to design of lattice material with higher performance.
2018, Vol. 39 
