Faculty of Engineering

Permanent URI for this communityhttps://rda.sliit.lk/handle/123456789/4203

Browse

Filters

2016 - 20172

Advanced Search

Filter by

Settings

Author: search.filters.author.Khorasany, R. M. HSubject: search.filters.subject.fuel cells

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    PublicationEmbargo
    In-situ simulation of membrane fatigue in polymer electrolyte fuel cells
    (Pergamon, 2017-04-20) Khorasany, R. M. H; Singh, Y; Alavijeh, A. S; Rajapakse, R. K. N. D; Kjeang, E
    Estimation of membrane fatigue lifetime under in-situ conditions involving cyclic hygrothermal stress is of particular interest in fuel cell durability research; however, conducting experiments to study the in-situ fatigue process within membranes is often expensive and in many cases, infeasible. Here, an in-situ numerical fatigue model based on the Smith-Watson-Topper (SWT) criterion is presented and validated against experimental results of membrane fatigue lifetime under humidity cycling in a fuel cell. The amplitude of strain oscillations is found to have a profound impact on the membrane fatigue lifetime. Importantly, it is also discovered that membrane fatigue failure occurs earlier under the channels than under the lands. The model is further used to simulate the membrane fatigue lifetime under operationally representative conditions of simultaneous temperature and humidity cycling where the lifetime is severely reduced due to increased amplitudes of strain oscillations.
  • Thumbnail Image
    PublicationEmbargo
    Ex-situ tensile fatigue-creep testing: a powerful tool to simulate in-situ mechanical degradation in fuel cells
    (Elsevier, 2016-04-30) Alavijeh, A. S; Venkatesan, S. V; Khorasany, R. M. H; Kim, W. H. J; Kjeang, E
    An ex-situ tensile fatigue and creep based accelerated stress test (TFC-AST) is proposed to evaluate the mechanical stability of catalyst coated membranes (CCMs) used in fuel cells. The fatigue-creep action of the TFC test is analyzed by tensile and hygrothermal expansion measurements on partially degraded specimens supplemented by microstructural characterization using transmission electron microscopy, revealing significant decay in mechanical properties as well as morphological rearrangement due to the combined fatigue and creep loading. Through comparison with in-situ hygrothermally degraded CCMs, the TFC-AST protocol is demonstrated to be an economical alternative to the costly in-situ mechanical accelerated stress tests that can reduce the test duration by more than 99%.