FCM燃料热-力耦合行为仿真建模和计算方法

为评估全陶瓷微封装（fully ceramic micro encapsulated, FCM）核燃料的性能，研究由三层各向同性碳包覆（tri structural isotropic, TRISO）燃料颗粒弥散于碳化硅（SiC）基体形成的柱状芯块的填充算法，开发相应的微观结构生成程序，利用并行有限元法对FCM核燃料的热 力耦合行为进行初步分析。结果表明，基于等球Packing的TRISO燃料颗粒填充算法可以快速生成高体积比的FCM燃料结构，基于共轭梯度迭代的隐式有限元法在求解大规模热 力学耦合问题时具有较高的效率和稳健性。本文方法可用于该核燃料每个颗粒和基体内部温度与应力分布的详细计算。

Computing and modeling method on thermal mechanical coupling behavior of FCM fuel

To evaluate the performance of fully ceramic micro encapsulated(FCM) nuclear fuel, the filling algorithm of the cylindrical pellet formed by dispersing tri structural isotropic(TRISO) fuel particles into SiC matrix is studied. The corresponding micro structure generation program is developed, and the thermal mechanical coupling behavior of FCM nuclear fuel is analyzed by parallel finite element method. The results show that the micro structure of the FCM fuel with high filling ratio can be quickly generated by the TRISO fuel particle filling algorithm based on sphere Packing, and the implicit finite element method based on conjugate gradient iteration has high efficiency and robustness in solving large scale thermal mechanical coupling problems. This method can be used to calculate the internal temperature and stress distribution of each particle and matrix of the nuclear fuel in detail.