With many fracture research studies, there is a need to compare frequently experimental findings and modeling simulations. One example is when studying the relationships between crack velocity and dynamic strain energy generated in polymers. It helps in these cases if the same computer can perform the modeling simulations as used to capture and process experimental data. Personal computer (PC)-size machines are often used to capture experimental data, and a fracture simulation model has been devised that can be hosted on a personal computer. In this study, the model is used with the frozen tongue experimental technique to research steady state crack propagation in medium-density polyethylene (MDPE). This is to study the generation of dynamic strain energy in the material and the factors affecting its availability to the crack tip. This includes the effects of changes in the material's properties immediately about the crack tip, the conditions that determine the threshold to just maintain crack propagation, and the conditions that determine the relationship between crack velocity and strain energy up to the limiting crack velocity.