VULNERABILITY OF STRUCTURAL SYSTEMS .1. RINGS AND CLUSTERS

A theory of structural vulnerability is developed and presented in two linked papers, initially for two dimensional frame structures. The pu rpose of the theory is to enable the identification of the most vulner able parts of a structural system so that they may be suitably protect ed and monitored. In Part 1 a graph model is used to analyse various l oad paths and loops within a structure. The most important new concept presented is that of a structural ring. A structural system is repres ented at various hierarchical levels of definition in terms of cluster s of structural rings. A measure of the quality of well-formedness of structural rings and clusters is developed which in Part 2 will be use d as a quantitative estimate of structural vulnerability.