Damage tolerance in parallel systems

Damage tolerance is a fundamental prerequisite for the safety and robustness of large complex systems. Here we analyze the response of a system of parallel rods under a damage event. The approach is based on the presence of multiple load paths in a complex structure, that is, various ways to perform a task. We found that, as much as the complexity increases, the presence of effective ways of carrying the load becomes crucial for the robustness of the structural system under a damage process acting at random on the structure. In addition, the size of the system plays an important role: although tendentially more fragile, large systems are able to redistribute and absorb the effects of damage even with low complexity. The results, here discussed with reference to mechanical systems, can be exported to other disciplines.