Structural Design of a Double-Layer Grid Using the Continuum Method: Equivalent Stiffness of the Continuum Model

The use of double-layer lattice structures in architecture and structural engineering offers advantages due to their high load-bearing capacity and efficient use of materials. However, the modelling and analysis of such structures can be complex and time-consuming, because of the large number of individual elements involved. This paper presents a simplified approach using the continuum method for the mechanical analysis of planar double-layer grids. A two-step homogenization method is applied: first a unit cell of the top and bottom single-layer lattice is used to create a continuum model at the micro scale, then this model is used to derive the global properties of the entire double-layer structure at the macro level. The stiffness properties of the continuous model are derived from the relationship between the stresses and the deformations of the unit cell structure. The proposed method reduces computational complexity, making it suitable for preliminary design and optimization of lattice structures.