Mechanical Fatigue of Polymer Foams - A Review

Polymeric foam applications have rapidly increased over the years and most of them are submitted to cyclic loading conditions. Therefore, their fatigue behavior is highly important to ensure safe operation for which limited information is available compared to compact materials like asphalt, concrete, and metals. Starting with an understanding of the main parameters controlling the mechanical properties of polymer foams, this literature review further presents a broad overview of the information available to understand the relations between loading conditions and fatigue lifetime, including damage level development. The review is composed into three main classes of polymers: thermoplastics, thermosets, and elastomers. The effect of loading conditions, including stress/strain amplitude, loading ratio (R, r), frequency (f), moisture content, type of deformation and temperature (T) is presented and discussed. Finally, the effect of foam morphology in terms of cell size (d) and density (ρ) on the fatigue performance is included to make a link between Paris' law and crack propagation. A conclusion is also provided with openings for future development.