Calculations have been carried out to evaluate the effectiveness of a range of carbon- and hydrogen-rich materials for shielding against energetic heavy ions relevant to the galactic cosmic ray spectrum. Experimental work integrated with the calculations included both preparation and characterization of physical properties of candidate materials and measurements of fragmentation (breakup) of ion beams of 16O and 40Ar in the tens of GeV energy range in these materials. We have simulated the fragmentation experiments using both the HETC-HEDS and PHITS high-energy particle transport codes. The purposes of these computational simulations were to investigate the effectiveness as spacecraft personnel shielding of various novel as well as commercially available materials for future lunar and interplanetary missions and to validate the codes against experimental data. In the present contribution we report results of the fragmentation simulations and compare them with examples of the experimental measurements.