Multiscale modeling approach of solid oxide cell contacts with dimensional tolerances for estimating electrical contact resistance.

During manufacturing of a solid oxide cell stack, tolerances on the metallic interconnects affect contact pressure distribution in the active area, which is known to influence electrical contact resistance. Finite Element Methods may be used to analyze the effects of these tolerances, however, due to complex interconnect designs and large number of contacts in a stack, such simulations are computationally expensive. In this work, with an aim to reduce computational cost, the homogenization approach is investigated for thermal expansion and relaxation behavior on interconnect contacts during operation while considering their dimensional variability. This is achieved by designing a novel constitutive material model and implementing it into the finite element framework. The output of this model is then used to evaluate the contact resistance at the SOC contacts, creating a theoretical framework to determine contact losses in a stack considering tolerance distributions on the interconnect contacts. • Tolerances on interconnects studied using homogenization approaches. • Constitutive equations representing tolerances as material properties. • Contact pressure at operational temperatures considering dimensional variability. • Effects of thermal expansion, temperature dependent moduli and creep/relaxation. • Finite element approach to calculate contact resistance at interconnect. [ABSTRACT FROM AUTHOR]