Uniaxial local buckling strength of periodic lattice composites

To reveal the local buckling strength of periodic lattice composites, an important factor in optimal material design, analytical method based on the classical beam-column theory was applied. Buckling modes were decided according to the condition that the curvature of the strut columns is the smallest. Characteristic equations were built according to the equilibrium equations. The buckling strengths and constraint factors of various grids under uniaxial compression and tension were achieved. The strut network supports stronger rotation restrictions than pin-jointed nodes but weaker than the built-in ends. With more stacks of struts and connectivity at nodes, the restriction must be stronger and the buckling load is greater. Commonly, the constraint factors of isogrids and mixed triangle grids are greater than Kagome grids. The regular honeycomb and square grids possesses smaller buckling loads.