Samcef ROTORS versus MSC NASTRAN V** Patrick Morelle – 8/8/2012 ableMAX http:WWW.//ablemax.co.kr 5nd floor, Hanho Building, 90-14 SamSung-1 Dong, KangNam-Gu, Seoul, Korea Republic of TEL: 02) 539-5212 FAX: 02) 539-5213 E-mail: info@ablemax.co.kr

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 Copyright LMS International

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 Copyright LMS International

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 Copyright LMS International

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 Copyright LMS International

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). Copyright LMS International