I am working on supply network resilience, I am looking for a good simulator (R, Java or Python) to simulate the supply network by using network metric concepts.
Your question is very interesting from two aspects: Resilience and Simulation.
With respect to Resilience, I strongly recommend you to first find proper metrics for measuring level of resiliency of your network.
But, regarding the simulation aspect, as you are going to deal with a network (particularly, in context of a supply chain), I suggest you to see Visual SLAM and AweSim program. More particularly, you could easily make some functions in C++ for measuring your interested resilience metrics and define them for AweSim.