Modeling the original and cyclic compression behavior of non-woven gas diffusion layers for fuel cells

Determination of the Orthotropic Mechanical Elastic Properties of Gas Diffusion Layers for PEMFCs

“…A zoom on the compression pressure lower than 5 MPa shows a curve shoulder that appears for all samples, with the exception of the samples 39AA and 39BC. As proposed in a recent study, 44 this peak reveals the effect of the pressure applied during the manufacturing process of the GDLs and will be named thereafter σ . P The value of σ P can be then evaluated for each sample via the inflection point after the mentioned peak.…”

Mechanical response of carbon paper gas diffusion layer under patterned compression

“…The average stiffness is defined as 𝐾 𝑎 = 𝜕𝑝 𝑎 /𝜕𝑡 𝑚 , representing the apparent stiffness of the GDL under patterned compression. Moreover, mechanical response of fibrous material is often represented as a function of relative density [29,[42][43][44]. In the present study, this quantity cannot be directly measured, as the heterogeneous compression induces disparities of relative density in the GDL.…”

“…In the present study, this quantity cannot be directly measured, as the heterogeneous compression induces disparities of relative density in the GDL. Nevertheless, its value under the ribs has been assessed as a function of the measured thickness using the following equation [29,44]:…”

“…Nonetheless, on the same stress interval, several authors observed a decreasing stiffness rather than a plateau, resulting in inflections on the stress-strain curve, with various interpretations. Carral and Mélé [29,44] referred to the effect of a compression pressure applied during the manufacturing process which damages the material. Thus, it would cause a different material response at low stresses, while the "original behavior" would only be observable for stresses higher than the manufacturing compression pressure.…”

“…However its implementation requires more input data, especially on the microstructural properties. Recently, Carral and Mélé used the fibrous material model developed by Van Wyk and Toll [42,43] to represent the compressive behavior of non-woven GDL, including its cyclic response [29,44].…”