MotionView provides several advanced component mode synthesis (CMS) methods for structural analysis: Craig Bampton, Craig Bampton with Geometric Stiffness, Craig Chang, and Craig Chang with Contact.
In this example, we compare the results of a flexible body modeled using the Craig Bampton and Craig Chang methods. The model in question is a dual-slot component used in a four-bar linkage. Flexprep was utilized to generate the flexbodies, and mode shapes were visualized by loading the H3D file into HyperView. Additionally, mode shapes and natural frequencies were compared by opening the .out file in a text editor.
Up to mode 16, both methods yield similar natural frequencies and eigenvalues. However, deviations in mode shapes become apparent beyond this point.
Deformation, Stress, and Strain Comparison: The dual-slot component was analyzed with one end fixed and the other allowed to rotate about the Y Global axis, with a velocity of 3.14 rad/s applied to the crank. Comparing results in HyperView shows that both flexbodies produced similar outcomes, demonstrating that both methods yield comparable results in this context.