LSCF材料氧化还原过程的力化学耦合瞬态三维模拟

 镧锶钴铁氧体(LSCF)具有良好的化学催化性能和导电性能，未来有望被应用于能源工程领域．在周围环境氧气浓度变化时，LSCF 会通过化学反应与周围环境交换氧．这一过程往往会引起化学应力并可能危害设备安全．本文对LSCF 棒在氧化还原循环过程中的反应-扩散过程进行了力化学耦合建模．表面处的化学反应动力学考虑了浓度、应力和温度的影响．通过有限元方法分别求解出三种给定的不同表面化学反应速率下棒伸长量和棒端部附近第一主应力的瞬态解．

A Fully Coupling Chemo-Mechanical Transient 3-D Simulation of Redox of LSCF

 Lanthanum strontium cobalt ferrite (LSCF) has many potential applications in energy engineering for its high catalytic performance and ionic conductivity. Changes in environmental oxygen partial pressure can lead to the exchange of oxygen between LSCF and the ambient gas through redox reaction on the surface. This process often causes chemical stress and hence may endanger the safety of the device. In this paper, a fully coupling chemo-mechanical modeling of the reaction-diffusion process of an LSCF bar during the redox cycle is carried out. The chemical kinetic of redox on the surface takes the effects of concentration, stress and temperature into account. The finite element method is used to obtain the transient solutions for elongation and the first principal stress at the end of the bar under three given reaction rates.