Compression impact behaviour of agglomerated cork at intermediate strain rates

This work analyses the influence of intermediate strain rates, between 25 and 75 s⁻¹, on compressive behaviour of agglomerated cork. Quasi-static and dynamic compressive tests on an agglomerated cork with two different densities were carried out. This work complements previous research focused on higher strain rates. The influence of strain rate on less studied properties as densification strain or Poisson ratio is also studied. Digital image correlation (DIC) is applied to the estimation of the strain distribution in the longitudinal and transversal directions for both materials quantifying their heterogeneity through the specimen. Under the studied dynamic conditions, no significant influence of strain rate on the mechanical properties was found. Young's modulus, plateau stress, and Poisson ratio are higher in the densest agglomerate, whereas the densification strain is similar in both material densities. Differences in properties such as Young's modulus, Poisson ratio, plateau stress, and densification strain have been found between quasi-static and dynamic conditions for both agglomerates. In the agglomerate with the lowest density, all properties are higher in dynamic conditions than in quasi-static conditions. In the material with the highest density, Young`s modulus and plateau stress increase significantly, whereas the Poisson ratio decreases.