A novel structural resilience index: definition and applications to frame structures

Resilience is the ability to undergo disruptive events without suffering complete failure and minimizing undesirable consequences thereof. Many attempts have been done in the recent literature in order to define quantitatively synthetic resilience measures of mechanical structures. They have been conceived as to be useful in comparing and classifying the resilience of different structures. In this paper we propose a novel rational and deterministic structural resilience index, based on a worst-case disruptive event, and making use of a minimalistic kinematics-based mechanical description. Particular emphasis is given to the computation of such a new structural resilience index for a generic frame structure, it being possible without the use of automated algorithms and an analytic expression of it has been achieved in terms of the numbers of ports (modules) and floors. First of all, keeping fixed the number of modules, the resilience index decreases as the number of floors increases. Secondly, keeping fixed the number of floors, the resilience index increases as the number modules increases. Finally, we notice that the case with infinite floors has a lower resilience index with respect to case of infinite modules, which is, as expectable, more resilient.