FModal: A Flexible Body Dynamics Modeling Pipeline for G Analysis

In this article, we describe the FModal tool that has been designed to bridge the gap between the structural dynamics and GC domains to develop a pipeline to facilitate the use of high-fidelity flexible body models for GC development. FModal streamlines the process of generating modal data including residual vectors and modal integral terms from component NASTRAN structural dynamics models for use in flexible multibody dynamics tools. The data generation process can be tailored to meet the simulation fidelity and performance needs. FModals output is a portable HDF5 file with hierarchical, well-organized, and labeled data that can be interfaced with multibody tools to automate and simplify the model data transfer process. FModal can be used to extract the critical data needed for flexible multibody dynamics simulations from a NASTRAN structure model and automate the transfer to a multibody dynamics and GC analysis tools. FModal can thus reduce the time needed to create flexible body models and errors in the model transfer process leading to faster design iterations and reduced time and costs. In this paper, we describe the interface between FModal and the DARTS flexible body dynamics tool and several validation studies to exercise and validate this new pipeline.