When Femap wrote out the Nastran input file in the default short-field format, the spacing between some nodes was on the order of mm, which, when described in meters, are essentially the same number. Solution was to either maintain mm units or use long field format, which is an option under the Bulk Data options dialog (edit analysis). Nastran is a separate finite element solver product that can be bundled within Femap. Simcenter Nastran (formerly NX Nastran) is an actively-developed offshoot of the Nastran code base, but is one of the most common solvers for finite element analysis (FEA). Nastran is essentially the math behind FEA. The Autodesk Inventor Nastran Story This video provides an overview of the uses and benefits of the Inventor Nastran advanced simulation software for finite element analysis (FEA). The FEMCI website is an online archive of mostly Nastran-based finite element analysis information. Some information can be applied to other finite element analysis programs, such as the principles behind the validity checks, but in general, FEMCI is exclusively Nastran.
Achieve computational performance, accuracy, reliability and scalability Simcenter Nastran is a premier finite element method (FEM) solver for computational performance, accuracy, reliability and scalability.