The Crack Growth Resistance of Polymeric Cellular Materials Studied With a Quasi-Brittle Approach

This research delves into the fracture analysis of cellular thermosetting polymers using Mode I fracture tests with a compact tension geometry subjected to both monotonic and cyclic loadings. The equivalent linear elastic fracture mechanics concept effectively described crack initiation and propagation. Numerical simulations estimated the equivalent linear elastic crack length aligning with experimental measurements. Resistance curves revealed a transient regime followed by a self-similar regime with relatively constant fracture energy, typical of quasi-brittle materials. Finally, the fracture energy evolution correlated with macroscopic density evolution exhibiting a linear relationship relaying the influence of microstructure to a second order.