A three-dimensional numerical model based on the finite element method (FEM) is constructed to calculate the thermal stress distribution in a planar solid oxide fuel cell (SOFC) stack with external manifold structure. The stack is composed of 5 units which include cell, metallic interconnect, seal and anode/cathode current collectors. The temperature profile is described according to measured temperature points in the stack. It can be clearly seen that the maximum stress concentration area appears at the corner of the components when the stack is heated from room temperature (RT) to 780 °C. The effects of stack components on maximum stress concentration have been investigated under the operation temperature, as well as the thermal stress simulation results. It is obvious that the coefficient of thermal expansion (CTE) mismatch between the interconnect and the seal plays an important role in determining the thermal stress distribution in the stack. However, different compressive loads have almost no effect on stress distribution, and the influence of glass-based seal depends on the elastic modulus. The simulation results can be applied for optimizing the structural design of the stack and minimizing the high stress concentration in components.

建立了基于有限元方法（FEM）的三维数值模型，以计算具有外部歧管结构的平面固体氧化物燃料电池（SOFC）堆中的热应力分布。电池堆由5个单元组成，包括电池，金属互连，密封和阳极/阴极集电器。根据堆栈中测得的温度点描述温度曲线。可以清楚地看到，当将堆叠从室温（RT）加热到780°C时，最大应力集中区域出现在组件的角部。在工作温度和热应力仿真结果的基础上，研究了堆叠组件对最大应力集中的影响。显然，互连件和密封件之间的热膨胀系数（CTE）不匹配在确定堆叠中的热应力分布方面起着重要作用。但是，不同的压缩载荷几乎对应力分布没有影响，并且玻璃基密封的影响取决于弹性模量。仿真结果可用于优化堆栈的结构设计，并最大程度地减小组件中的高应力集中。