FMI for Sharing NASTRAN Dynamic FEM models

This paper presents an approach for sharing dynamic FEM structure models built in NASTRAN environment through the Functional Mock-up Interface (FMI) standard. Relevant data such as stiffness and mass matrices is generated in HDF5 database from modal analysis solution without the need for altering of NASTRAN solution sequence. State space Linear Time Invariant (LTI) model is generated from this dataset which represents the dynamics of structure model in modal coordinates. Nodal accelerations, displacements and elemental stresses can be output from FMI model by constructing the output matrix from eigenvectors and modal stress contribution data at desired element IDs. Generated FMI model is simulated in Simulink and is compared with NASTRAN modal transient solution which shows good correlation.