Observation of the microstructural evolution in a structural polymeric foam using incremental digital volume correlation

Abstract

Polymeric structural foams are widely used in many engineering applications due to their exceptional properties including high specific strength and energy absorption. The mechanical properties depend strongly on their microstructures, which also dictate their load-bearing capability under deformation. However, the mechanical behavior of polymer foams in compression is not well understood, due to the complex local deformation and strain characteristics associated with the cellular microstructure. In this paper, unconfined uniaxial compression of a polymeric structural foam was conducted while its microstructure was determined using micro-computed tomography (micro-CT) subjected to large deformations. The detailed local deformations and strains are obtained by using three dimensional digital volume correlations (DVC) method. This incremental DVC allows the use of intermediate bridging images to determine large nonlinear deformations in the foam under compression. The evolution and deformation mechanism of the microstructure are observed during different compression stages using the incremental DVC techniques. © The Society for Experimental Mechanics, Inc. 2014.