STRUCTURAL MECHANICS OF LATTICE GRIDS

Lattice grids are new-type materials with high specific stiffness and specific strength.The topologies of the 2D periodic lattices are analyzed together with their manufacturing methods.Equivalent continuum methods to obtain effective stiffness,strength and yield surfaces are discussed,including the micropolar elastic theory of the lattice structures.The size effect and influence of soft or rigid inclusions are analyzed.The fracture mechanics analysis on the cellular grids shows that the triangular and hexagonal grids are flaw sensitive,while the Kagome lattices are damage tolerant.The lattice grids may be classified into grid structures,grid stiffened structures and grid sandwich structures.The failure modes,the optimzation principles and the experiment results are discussed in details.The recent work of the authors on carbon fiber reinforced lattice materials are also introduced.