Characterization of Strain Distribution in a Reinforced Rubber-Matrix Composite using Digital Volume Correlation

摘要

A rubber-matrix composite specimen, reinforced with nylon cords, was examined using the volumetric strain measurement technique known as Digital Volume Correlation (DVC) and modeled using a specialized finite element method. The specimen was imaged in an X-ray micro-CT system in a custom load frame. Image sets were acquired at zero-load and at a single, applied tensile load. Dispersed glass micro-beads and voids served as a suitable volumetrically distributed speckle pattern for application of the DVC technique. A specialized set of modeling codes, developed at the US Air Force Research Laboratory, was used to model the specimen. These codes were used to establish the geometry of the nylon reinforcement cords, mesh these resulting solid descriptions, and perform a unique stress analysis on the complicated rubber and cord combined architecture. Constituent material properties were also established in this research. Comparisons between the experimental and modeled full-volume deformation fields yielded quite close agreement in both global behavior and local behavior, throughout the volume examined. Both the DVC results and modeling results indicated extensive influence of the nylon cord reinforcements on the strain variation, as would be expected.