The protection of light-weight ground vehicle crews from rapid energetic events in hostile operating environments is an active field of study in defense research. In the following work an innovative optimization scheme is developed which couples finite element blast simulations with a spatially decomposed design methodology. The objective of this method is to develop concept designs to improve occupant survivability and reduce key injury metrics. The Hybrid Cellular Automata (HCA) framework has been adapted to develop improved designs of the target and supporting structures under blast loading. The BlastHCA methodology is shown to generate functionally improved thin walled structures for both empirically based and fully coupled blast simulation loads. Functionally enhanced concept designs developed by the BlastHCA methodology will serve to better the understanding of the blast mitigation design problem and produce structures that offer better crew protection for the next generation of lightly armored ground vehicles.