Connectivity of two-dimensional assemblies: trusses and roads

The concept of 'structural connectivity' is introduced to assess the connectivity of structural trusses and road networks, which are examples of two-dimensional assemblies. Metrics for such connectivity, and also for identifying the least connected members and zones, are derived from an adaptation of the 'Bristol approach' (based on joint stiffness), Newman's method (based on network theory), and Route Structure Analysis (developed to analyse road networks). Fractal, Warren and Fan-type trusses of the same triangular outer shape but differing internal geometric configurations were analysed using all three approaches, both to explore similarities across metrics and to find the best-connected truss. Although the different measures gave somewhat different results for the same structure, there was some degree of consistency; thus enabling the Warren truss to emerge as the best-connected configuration. The metrics indicated that truss ends and chord members were the least connected areas and members; but that increasing the axial rigidity of chord members improved the connectivity of all truss forms. An idealised 'Class A' road network in Sri Lanka was analysed, using a combination of Newman's method and Route Structure Analysis, as proof that the concept of structural connectivity could be applied to assemblies other than engineering structures.