Study of Reticulated Vitreous Carbon Foam as a Quasi-Brittle Material
Quasi-brittle materials are those where the addition of specific microstructural features such as porosity can lead to departure from linear elastic behaviour prior to maximum force, followed by graceful failure. A simple example of a quasi-brittle material is reticulated vitreous carbon foam; an open-cell structure consisting of brittle ligaments connected in a three-dimensional array. Tensile testing measurements have been made on foams with various pore and ligament dimensions; force - displacement combined with acoustic monitoring together with the evaluation of the associated elastic moduli and fracture strengths. These tests give insights into the mechanisms of quasi-brittle failure, and the results are explored using simple considerations of elastic energy storage throughout process zones.