Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Mechanical Engineering
Numerical Investigation Of Mechanical Durability In Polymer Electrolyte Membrane Fuel Cells, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson, Simon Cleghorn, William B. Johnson
Numerical Investigation Of Mechanical Durability In Polymer Electrolyte Membrane Fuel Cells, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson, Simon Cleghorn, William B. Johnson
Mechanical Engineering Faculty Publications
The relationship between the mechanical behavior and water transport in the membrane electrode assembly (MEA) is numerically investigated. Swelling plays a key role in the mechanical response of the MEA during fuel cell operation because swelling can be directly linked to the development of stresses. Thus, in the model introduced here, the stresses and the water distribution are coupled. Two membranes are studied: unreinforced perfluorosulfonic acid (PFSA) and an experimental reinforced composite membrane. The results suggest that open-circuit voltage operations lead to a uniform distribution of stresses and plastic deformation, whereas under current-load operation, the stresses and the plastic deformation …
On The Mechanical Response In A Thermal Barrier System Due To Martensitic Phase Transformation In The Bond Coat, Anette M. Karlsson
On The Mechanical Response In A Thermal Barrier System Due To Martensitic Phase Transformation In The Bond Coat, Anette M. Karlsson
Mechanical Engineering Faculty Publications
Recentstudies have shown that Pt-aluminide—a common bond coat material inthermal barrier coatings—undergoes martensitic transformations during thermal cycling. The transformationsare associated with both large transformation strain and a strainhysteresis, leading to accumulation of a mismatch strain. Thermal barriersystems based on Pt-aluminide bond coats are susceptible to interfacialmorphological instabilities. In this study, we investigate how the cyclicmartensitic transformation influences the morphology. Two key results are: (i)the morphological instabilities are highly sensitive to the thermo-mechanical propertiesof the substrate due to the martensitic transformation; (ii) thehysteresis associated with cyclic martensitic transformation cannot drive the morphologicalinstabilities; the strains associated with the formation of the thermallygrown …