中文摘要：

本工作建立了受气泡内压作用的双气泡 UO2模型，利用有限元方法得到燃料颗粒受气泡内压作用、不同气泡间距条件下的燃料颗粒应力分布结果，并讨论了气泡间距、气泡半径和气泡内压对气泡之间相互作用的影响。研究结果表明，受气泡相互作用的影响，燃料颗粒内部产生了应力集中，应力集中倍率与气泡间距和气泡半径的比值（距径比）有关，与气泡内压无关。当距径比等于1时，应力集中倍率约为未考虑气泡相互作用影响时的2倍。当气泡尺寸不同时，应力集中主要发生在靠近小气泡的燃料基体处。

英文摘要：

The UO2 dual bubbles model under bubble internal pressure was proposed , and the stress distribution of fuel particles under different intra-bubble distances was calculated by using the finite element method . T he effects of intra-bubble distance , bubble radius and bubble internal pressure on the interaction of bubbles were discussed . T he results show that w hen the interaction of bubbles is considered , stress concentration occurs and locates at the fuel particles between bubbles .The rate of stress concentration is related to the ratio of intra-bubble spacing to bubble radius （spacing radius ratio ,SRR） but unrelated to the bubble internal pressure .When SRR equals 1 , the stress concentration rate is about twice that when the interactions of bubbles are ignored . When the sizes of bubbles are different , the stress concentration occurs primarily at the fuel near the small bubbles .