Some Observations on Designing Double Layer Grids

The manner in which three dimensional lattice structures are analysed and designed is reviewed in terms of the reliability of the final design, with a consideration of the consequences arising from the special form of these structures. The wide variety of nodal details and member types makes it difficult to deal with each specific system but the essential behaviour, interactions and the modes of failure are discussed. Although it is held that linear elastic analysis and the application of existing standards will, in general, provide safe structures, there is a need to be aware of those aspects of the performance which are not treated in current codes.