Abstract: To study the cascading failure of multi-community networks, a network model with adjustable community size and structure is designed. Based on the classic linear load-capacity model, a three-stage node failure model of initial load, tolerable load and critical load is proposed. Deliberate attacks and random attacks are used to attack the network, and the robustness of the network is analyzed through changing in evaluation indicators. Simulation results show that the robustness of multi-community networks is good in random attacks, but the robustness of multi-community networks is poor in deliberate attacks. If the initial load of the node is low, the network will be robust. If the nodes in the community are evenly connected and the nodes with a low initial load are connected between the communities, the network will be robust.Adding a secondary tolerable load to the head node and limiting cascading failures within a community will make the network vulnerable and easily cause network cascading failure reactions.

Key words: multi-community network, head node, load tolerance, critical load, distribution strategy, cascading failure

摘要： 为研究多社团网络级联失效问题，设计一种社团规模和结构可调的网络模型。在经典的线性负载-容量模型基础上，提出一种初始负载、容忍负载、临界负载三个阶段节点失效模型。采取蓄意攻击和随机攻击方式对网络进行攻击，通过评估指标的变化分析网络的鲁棒性。仿真结果表明：随机攻击时多社团网络鲁棒，蓄意攻击时多社团网络脆弱；节点初始负载越低，网络越鲁棒；社团内节点连接越均匀，社团间连接初始负载越低的节点，网络越鲁棒；给头节点附加二次容忍负载和将级联失效限制在一个社团内，网络越脆弱，容易引起网络级联失效。

关键词: 多社团网络, 头节点, 容忍负载, 临界负载, 分配策略, 级联失效