Robustness Modeling and Optimization of Multi-Layer Storage and Supply Networks for Equipment Support

To investigate the vulnerability of equipment transportation systems under cascading failures, this study models the system as a two-layer coupled network consisting of a storage–supply layer and a transportation layer within a multilayer complex network framework. The model captures both intra-layer structural properties and inter-layer coupling dependencies. A unified multilayer node-importance metric is proposed, integrating layer-level structural contribution with intra-layer centrality to achieve cross-layer comparable and interpretable node ranking. Based on this, a load-capacity–state coupled cascading failure model is developed, incorporating node capacity constraints, dynamic state transitions, and importance-aware load redistribution. Benchmarking experiments against degree, betweenness, multiplex PageRank, and TOPSIS-based methods show that the proposed metric leads to the fastest robustness degradation and the smallest area under the robustness curve, indicating superior capability in identifying cascade-critical nodes. The results demonstrate that targeted attacks significantly degrade network performance, especially when coupled nodes fail. The findings suggest that prioritizing protection of critical nodes and optimizing load redistribution can effectively enhance system resilience.