Tropocollagen molecules in a network can suffer two major modes of damage: damage at cross-linking sites (represented as clusters of head groups in this model) or damage within a molecule . The damage at cross-linking sites is accounted for by the presence of Lennard-Jones pairwise interactions between head groups, which allows for damage to be repaired. The potential model for polymer interactions has been described in previous work by Bailey and Wilson . The core components are coarse grained polymers made up of six beads, where the two ends are "head beads" and the remaining beads are "body beads".