核废料储库周边介质热力耦合数值分析

Thermo mechanical coupling analysis of nuclear waste repository

以热力学和热弹性理论为基础,分析热-力相互耦合作用及其对热特性参数和力特性参数的影响。建立了非等温条件下的耦合作用控制方程,给出了相应的空间离散和时间离散形式。利用有限元法对一核废料储库的平面问题进行了计算,讨论了储库周围粘性土介质内温度场、应力场等的动态发展变化规律,并分析了耦合效应对计算结果的影响。研究表明,随时间的增长,热能由储库边壁不断向远处传导和扩散,而在空间上又处于不断变化的非等温状态,这一动态变化过程必然会诱致周围土介质内应力的产生和发展,并随温度的变化而不断变化。

Based on thermomechanics and thermoelasticity theory, the thermomechanical coupling effects and their effects on thermal parameters and mechanical parameters are analyzed briefly. The coupling governing equation under conditions of nonisothermal state is established, and the formulations of spatial discretization and time discretization are given. Using finite element method, a practical plane strain problem of radioactive waste repository is analyzed. The computed transient distributions of temperature field, stress field are discussed; and the effects of coupling are also discussed. The studies show that, with the elapsed time, heat energy are continually conducted and diffused from repository to further distance, and this variation of temperature will inevitably cause the variation of stress state in the meantime.