NEi Software is a 20-year technology partner and the number one reseller of Femap in North America. Find out more about Femap. The NEi Nastran Engine is a powerful, general purpose Finite Element Analysis solver used to analyze linear and nonlinear stress, dynamics, and heat transfer characteristics of structures and mechanical components. This Normal Modes, Buckling, and Prestress FEA Analysis package expands on the capabilities of the basic Linear Static and Steady-State Heat Transfer package with the addition of the buckling, modal, and prestress solution types. As with NE-L1 all material models including composites and element types including 6 DOF/Node CQUADR and CTRIAR and parabolic solid elements are supported.