Shock response of an additively manufactured high solids loaded polymer composite with intentional porosity

The performance of additively manufactured (AM) composites subjected to dynamic loading can be significantly influenced by process-inherent heterogeneities such as non-uniform constituent distribution, interfaces, and porosities. In this work, temporally- and spatially-resolved measurements of macro-, micro-, and meso-scale heterogeneities were performed to investigate the shock response of AM-fabricated high-solids-loaded polymer composite. Samples with pre-identified heterogeneities in the form of pores were impacted in different orientations relative to the print direction of the filaments. X-ray phase contrast imaging (PCI) was used to study the void collapse process upon interaction with the shock wave front(s) and determine the shock and particle velocities via feature tracking. Also investigated were features such as shock front tilt, presence/creation of additional wave fronts, and shifts in shock velocity relative to its proximity to the porosity. Photon Doppler velocimetry (PDV) was simultaneously used to measure the sample free surface velocity and determine the effects of local directional porosity on the equation of state, which in our previous work was found to be independent of orientation effects in a similar material with more uniform distribution of pores.