本研究建立了针对多晶燃料蠕变问题建立多场耦合模型及算法，并通过FEPG平台实现数值模拟。发展了随机建模方法，并实现了复合燃料的隐形建模，以此为基础实现了复合燃料蠕变的有限元模拟。获得了UN-U₃Si₂复合燃料宏观等效蠕变率的多变量数理模型，并通过分析初步获得各应力、温度条件下的主导机制规律。本研究可以为单相核燃料及复合燃料蠕变性能研究提供技术支持，为新型事故容错燃料的优化设计和性能评价提供数值参考依据。

In this paper, a multi-field coupled model and algorithm for the creep problem of polycrystalline fuel are established, and the numerical simulation is realized by FEPG platform. The stochastic modeling method is developed and the composite fuel stealth modeling is realized. Based on this, the creep finite element simulation of composite fuel is realized. A multi-variable mathematical model of the macro-equivalent creep rate of UN-U3Si2 composite fuel was established. This study can provide technical support for the creep behavior research of single-phase nuclear fuel and composite fuel, and provide numerical reference for the optimal design and performance evaluation of new fault-tolerant fuel.