考虑裂变气体释放的高燃耗燃料颗粒动态开裂行为研究

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中图分类号：O34;TL349 文献标志码：A 文章编号：1000-4939（2025）06-1285-07

Abstract ：A large number of fision pores are generated in ceramic fuel under high burnup conditions，and the fission gas released into the crack cavity has a great influence on the crack propagation behavior.In this study，a dynamic crack propagation model under variable internal pressure is developed to address the dynamic cracking technique of the coupling effect between the internal pressure and crack propagation. The internal pressure in crack cavity varies with crack propagation，while the cracking behavior is simultaneously affected by the pressure.The presented model is successfully applied to simulate the cracking behavior of ceramic fuel particles of high burnup structure，and the mechanical effect offisson gas release on crack propagation is studied.Based on the cohesive element，the crack initiation and propagation process are simulated，and the mechanical research method of gas release on crack propagation is established here. Furthermore，the effcts of gas pressure on the crack initiation and propagation process in fuel particles are analyzed.The results show thatthe release of gas into the crack cavity can inhibit crack propagation based on gas pressure and crack geometry characteristics.For diffrent initial gas pressures，the larger the initial gas pressure is，the longer the crack propagation length will be.The developed dynamic cracking simulation technique provides ananalytical method and numerical foundation for accurately analyzing the failure of dispersion fuel meat.It also provides a method to study the coupling of load and crack propagation.

Key words：ceramic fuel particle; cohesive element; dynamic cracking; fission gas

在高燃耗辐照条件下，陶瓷燃料颗粒内产生大量裂变气体，不断聚集形成气泡，导致燃料颗粒辐照肿胀并出现大量微裂纹，最终影响基体的力学性能及整个燃料元件的结构完整性[1-3]。（剩余12229字）