Morphological and mechanical investigation of double layer reciprocal structures

From a technological point of view, reciprocal structures have the advantage of simplifying considerably connections in the sense that members are connected only by pairs. This constructional advantage has two main consequences: technological constrains are replaced by geometrical constrains and bending moments are increased through the non convergence of members to nodes with multiple connections. Geometrical constrains can be dealt by using form-finding methods such as dynamic relaxation algorithm. However resisting bending moments to gain stiffness is difficult without increasing the weight of the structure. For standard reticulated structures, common strategies consist in introducing curvature in the structure and/or modifying the structure into a double layer space structure. The proposed paper is thus an attempt to apply these strategies to reciprocal structures and to develop spherical domes with structural thickness. Several configurations will be investigated and compared in term of geometrical feasibility and structural performance.