TITLE:
Numerical Investigation on Residual Stress and Warping of Planar SOFC in Manufacturing
AUTHORS:
Xumeng Zhang, Jianguo Zhu, Wenlong Li
KEYWORDS:
Solid Oxide Fuel Cell, Residual Stress, Warping; Numerical Simulation
JOURNAL NAME:
Journal of Power and Energy Engineering,
Vol.10 No.5,
May
31,
2022
ABSTRACT: Residual thermal stresses and warping of the anode-supported
planar solid oxide fuel cell (SOFC) were estimated numerically. A 3D finite
element (FE) model with viscoelastic constitutive equations was established to
calculate the residual stress and warping for the cell. In the fabrication of
the cells, some mechanical restriction was employed during the high-temperature treatment
followed by a cooling stage in order to prevent the button cell from warping,
and then from these specific boundaries and loading conditions, a FE simulation
was used to calculate the distribution of the internal stresses in the cell.
The results indicate that the concentration of compressive stress appears in
the electrolyte layer, and that could cause interfacial micro-cracks or even
cohesive failure. Furthermore, from the numerical study, the annealing time (or
continuous cooling) is related to the residual stress in the material due to creeping. The compressive
stress in the electrolyte layer can be reduced significantly by increasing the
cooling time. Therefore, it is possible to optimize the annealing time in order
to make the SOFCs flat and have less residual stress, improving the mechanical durability.