A method and system provide the ability to generate models. A generative shelled base is created as a hollow computer-aided design (CAD) design. A t-spline mid-surface shell is created from the generative shelled base, which is then used to create a shell mesh model. A t-spline solid body is created from the generative shelled base, which is used to create an internal support structure that is converted into a shell CAD geometry, which is used to create a support structure mid-surface shell. The support structure mid-surface shell is combined with the shell mesh model into a generative mid-surface mesh that is used in a computer-aided engineering (CAE) crash simulation. The generated shelled base is combined with the shell CAD geometry into a generative shelled solid that is utilized in an additive build simulation.