1. Samcef ROTORS versus MSC NASTRAN V**
Patrick Morelle – 8/8/2012
ableMAX
5nd floor, Hanho Building, SamSung-1 Dong,
KangNam-Gu, Seoul, Korea Republic of
TEL: 02)
FAX: 02)

2. Comparison S4R - MSC NASTRAN
Dedicated GUI and integrated solution for rotor dynamics
Improved conical beam element (degenerated shell, better taking into account conical shafts)
2D Fourier models without limitations in the number of harmonics (0, 1 and higher orders). Possibility to use them for composite materials.
2D Fourier Lagrangian and Eulerian approach
No specific GUI. Rotor dynamics capabilities as part of global FE solution
Classical beam element
NO 2D capabilities
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3. Comparison S4R - MSC NASTRAN
1D, 2D, 3D, cyclic symmetry, multi stage cyclic symmetry, all exhibiting gyroscopic effect, and possibility to combine all of them
Superelement technique for rotating parts AND non rotating parts. The rotating superelement include reduced stiffness, mass, damping, gyroscopic and circulatory forces matrices
General gear element allowing to take into account coupling between axial, bending and torsion modes
Only 1D and 3D, no combinations between different types of models. 3D models are using static condensation method : the nodes are condensed along the axis of rotation (rough “rigid” gyroscopic effect versus our “flexibel” exact one)
Superelement technique ONLY for non rotating parts in inertial frame (except the requested static condensation of 3D model along axis of rotation …)
No gear
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4. Comparison S4R - MSC NASTRAN
Large library of specialized bearings (hydrodynamic bearing, rolling element bearing, squeeze-film damper, added mass effect fluid elements), prototype BEARING module for hydrodynamic bearings (normal and thrust)
Bearing element with 6X6 matrices (stiffness, damping (viscous or hysteretical), mass) The coefficients are either constant or variables with rotational speed, frequency or time
Bi-variable (rotational speed and frequency) bearing element with 6X6 matrices (stiffness, damping, mass)
No specific bearings (modelled with generic “spring”/CELAS + constraints/RBE elements), squeeze film damper available
General stiffness/Damping matrix (MATRIX27) CONSTANT (no dependency of the speed of rotation)
Only constant matrices
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5. Comparison S4R - MSC NASTRAN
Local non linearities are taken into account in the frequency domain ( non linear harmonic balance method). Available : bushing (clearances), rolling element bearing, squeeze-film damper, friction element
Improved integration schemes in time domain, and on non linear elements available : bushing (clearances), rolling element bearing, squeeze-film damper, friction element, hydrodynamic bearing element
Only classical harmonic analysis
No specific integration scheme and no specific non linear elements
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6. Comparison S4R - MSC NASTRAN
Specialized and advanced post-processing included in the GUI
Automatic 3D recombination of 2D and cyclic symmetry models including multi stage cyclic symmetry
Campbell diagram available for problems in inertial AND rotating frame. Very efficient mode tracking process.
No specific GUI, use command language to post-process rotor model
No 2D …
Classical mode tracking process (users complain about it).
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