Samcef Rotor

7/23/2019 Samcef Rotor

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SAMTECH, Integrating CAE towards Professional Solutions

SAMCEF for RotorsRotor Dynamics Analysis

SAMCEF for Rotors: a FEM basedProfessional solution specificallydedicated to rotating machinesanalysis.

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S AMCEF for Rotors is a solution specifically dedicated to the dynamic analysis of structures containing rotat-ing components. It is finite element based and allows to compute critical speeds, stability, harmonic andtime-transient response of mechanical systems made of rotating parts, static parts and linking devices.

CAE ENVIRONMENT• SAMCEF for Rotors is fully driven by SAMCEF Field, a user-friendly

interactive graphical user interface for modeling, analysis and post-processing of systems with rotating components.

• Data entry is easily done using contextual pull-down menus and pop-up boxes using a wide selection of preprogrammed functions for thedefinition of time or frequency dependent properties, rotational speedsand boundary conditions.

• A CAD modeler is integrated for modeling and data processing; theseare directly defined on the geometry. Some idealization proceduresare included in order to allow easy coupling between rotors and sta-tors. Graphical results post-processing can be performed in manydifferent forms: X-Y plots (Campbell diagram, frequency or time wiseevolution…), contour maps, animations…

ROTATING SYSTEMS MODELINGSAMCEF for Rotors can handle rotors with different rotation speeds; spin axisorientation is free. Fixed parts are modeled using the full SAMCEF standardFinite Element library.

Super-Elements (CRAIG and BAMPTON) can be used to model either rotat-ing or fixed parts.

RotorsSeveral Finite Element models are available to describe rotating parts. Allthese elements include the following capabilities:

• The gyroscopic effect is taken into account. The rotational speed canvary with respect to time or sweeping frequency. Rotor orientation isfree and the model can be made of several rotors rotating with diffe-rent rotational speeds;

• Either a viscous variable damping proportional to stiffness and massmatrix or a hysteretic damping (in the frequency domain) proportionalto stiffness can be associated to these elements. When the element isrotating, the viscous damping induces circulatory forces proportionalto the rotational speed, as the dynamic behavior is described in a fixedreference frame;

• Initial stress conditions can be defined;

• Forces related to an overall acceleration can be considered (gravity,maneuver…);

• The material properties can be temperature dependent.

Beam-mass-spring model

Beams elements are used to model shafts with rigid disks. A spring ele-

ment allows to introduce a local stiffness matrix between two nodes andcan be used to model shaft coupling. The cross-section can vary alongthe beam axis (hollow frustum).

Axisymmetrical model

Flexible rotors are modeled by 2D axisymmetrical shell or volume FiniteElements which displacement field is developed in Fourier series (Multi-harmonic elements). With this approach, it is no longer necessary to makea distinction between shaft and disks. A specialized linking element allowsconnection of 2D axisymmetrical models with 3D ones. These elementsare single or multiple layered when composite rotors have to be ana-lyzed.

3D model

Rotors can also be modeled by 3D shell or volume Finite Elements. Thismodel allows describing rotors with complex shape like impellers or fan.It is possible to mix the 3D model with the beam model.

Stators A comprehensive library of single or multiple layered elements (beam, mem-brane, shell, volume) makes it possible to model all types of structures. Theseelements take into account a viscous variable damping or a hysteretic damp-ing (in the frequency domain).

Linking devices• Linear bearing with variable properties;

• Hydrodynamic bearings;

• Squeeze-films dampers (several models);

• Bushing;

• Rubbing;

• Gear;

• Control elements (sensors and actuators).

Utility elementsSpecial element such as stiffeners, dampers, non-linear force elements, lin-ear constraint elements, distance indicator elements, clearance consumptionand controller elements or user’s defined elements allow characterization ofany kind of mechanical properties.

Linear constraints and rigid bodies can be defined between degrees of freedom.

Loads

• External forces include synchronous loads like unbalances as well as asyn-chronous loads like gravity and maneuvers in rotation and translation;

• Gravity loads, overall or local imposed acceleration;

• Radial unbalances or moments;

• Local imposed displacements or rotations.




ANALYSESLinear static analysis (SAMCEF Asef)Rotating systems can be subjected to linear static analysis, under generalthermo-mechanical loading conditions; in the particular framework of SAM-CEF for Rotors, preliminary linear static analysis aim principaly at predicting

initial conditions that can be taken into account in subsequent SAMCEF Dy-nam or SAMCEF Rotor/RotorT analyses.

Modal analysis and Super-Element creation(SAMCEF Dynam)For large models, fixed or rotating parts can be conveniently representedby Super-Elements, created using component modes synthesis (Craig andBampton algorithm) and characterized by reduced stiffness, mass, gyroscop-

ic, damping and circulatory forces matrices.

Critical speeds computation (SAMCEF Rotor)Several methods are available to solve bending, axial, torsional or coupledproblems. With the sweeping method, the user defines ranges of rotational

frequencies whithin which complex eigenvalues have to be computed.The direct method allows directly obtaining the critical speeds as eigensolu-tions. It is used for non damped gyroscopic systems with constant stiffness.

Frequency response analysis (SAMCEF Rotor)Several methods are available to compute the harmonic response to unbal-ances or asynchronous loads.

The Modal Method where the forces and matrices are reduced by projectionin a modal basis and the Direct Method that allows taking into account localnon-linearities (clearances, non-linear stiffness, squeeze-film dampers, userelements, rubbing…) through a Harmonic Balance approach.

Transient response analysis (SAMCEF RotorT)Transient response simulates run-up(or run-down) and blade losses. Itis using Newmark based integration

methods like HHT. Non-linear effectssuch as clearances, squeeze-films,hydrodynamic bearings or rubbingare solved using an iterative Newtonscheme. An automatic time steppingstrategy is available. If necessary, aninitial static computation can be per-formed.

Sensitivity and statistical analysis(SAMCEF Rotor)In the frequency domain (critical speeds and harmonic response), it is possi-ble to carry out a sensitivity analysis of the solution with respect to a variationof a set of design parameters. In particular, dynamic characteristics (stiffness,

damping) of bearing elements can be considered as design parameters.The sensitivities can then be used to estimate the standard deviation of thesolution when the standard deviation of the parameters is given.

GRAPHICAL POST-PROCESSINGEigenvalues

• Damping coefficients and frequencies as a function of the rotationalspeed (Campbell diagram);

• Damping coefficients and frequencies versus design parameters

variation;

• Confidence range of the Campbell diagram after a statistical analysis.

Curves

• The displacements, forces, reactions or stresses obtained by the forcedresponse as a function of time or frequency;

• Orbits after the transient analysis;

• Confidence range of the harmonic response after a statistical analysis.

Plots at given times or frequencies• It is possible to recombine the complex modes for a given phase

angle and to superimpose them on the initial structure. Displacements,rotations and energies can be obtained;

• Complex displacements, rotations, forces, moments and stresses afterthe harmonic response for a given frequency;

• Real displacements, rotations, forces, moments and stresses after thetransient response at a given time;

• For both frequency and time response, it is possible to animate the result.

DOCUMENTATIONFor direct access to information, the Users Guide and Help manual are avail-

able via your favorite navigator (HTML).

COUPLING SAMCEF FOR ROTORS WITHBOSS QUATTRO TASKS MANAGEMENT AND OPTIMIZATION PLATFORM

Besides specific capabilities offered by SAMCEF Rotor for sensitivity and statistical

analyses, SAMCEF for Rotors can be used in combination with BOSS quattro, in

both frequency and time domains, for general parametric studies and optimiza-

tion analyses, including model updating, design of experiments and response

surfaces.

PLATFORMSSAMCEF for Rotors is available on Windows 2000 & XP Pro platforms.




©2006 SAMTECH s.a. The trademarks and the registered trademarks are the properties of their respective owners.

About SAMTECH

Founded in 1986, SAMTECH is now the European leading provider of scientific analysis/optimization software (FEA, MBS,MDO), professional solutions and associated services. SAMTECH develops and commercializes:

“General-purpose software tools”: this SAMTECH offer includes the general linear and implicit non-linear Finite Element Analysis package SAMCEF with the CAD/CAE modeling environment FIELD, the general explicit and fast dynamics codeEUROPLEXUS; the task management and optimization platform BOSS quattro; TEA Mecano and TEA Thermal CAA V5 Basedas non-linear thermo-mechanical solution embedded in CATIA V5 and SAMCEF Gateway CAA V5 Based, the SAMCEFintegrated interface within CATIA V5.

“Professional solutions”: this SAMTECH offer is based on its general-purpose software tools and is dedicated to specificdomains of application like rotor dynamics, modeling of composite structures, mechatronic modeling of machine tools,mechatronic of wind turbines, modeling of transmissions, modeling of large deployable or inflatable structures, modeling ofpipes for automotive industry…

“Third party and customized solutions” like the SAFE tool (fatigue analysis of aeronautic structures) and the ApplicationCOMPOSITES (analysis of aeronautical composite materials structures) from AIRBUS, where SAMTECH provides its clientswith services such as development, reengineering, packaging and deployment of proprietary professional solutions on thecustomer site.

“Customized multi-physics solutions”, based on OOFELIE. OOFELIE is commercialized by OPEN Engineering, theSAMTECH subsidiary, that allows SAMTECH to be present on the multi-physics design markets and to provide services for thedevelopment of original highly coupled analysis solutions covering specific needs.

Visit www.samcef.com for further details on SAMTECH Product/Service offer!

Some References

Aerospace

AERMACCHI, AIRBUS, AIR LIQUIDE, ALENIA AERONAUTICA, ALENIA SPAZIO, ASC, AVIO, BOEING HELICOPTER, BOMBARDIER AERO-SPACE, CRYOSPACE, EADS-ST, ESA/ESTEC, EUROCOPTER, HUREL HISPANO, LATECOÈRE, MESSIER DOWTY, MTU, SABCA, SAGEM,

SNECMA-DMS, SNECMA Moteurs, SONACA, TECHSPACE AERO…

Transport

ADTRANZ, DAIMLER-CHRYSLER, DELPHI AUTOMOTIVE SYSTEMS, LOHR, PORSCHE, PSA, RENAULT, RENAULT SPORT, TUC RAIL…

Energy

ABB, AREVA, EDF, ENEL, GE ENERGY PRODUCT, RTE, SCHNEIDER…

Mechanics

APAVES, COMAU Systèmes France, GLAVERBEL, MAK, PICANOL, SAINT GOBAIN, SOLLAC…

Defence

CEAT, CEPR, CEVAP, DCN, DGA, GIAT INDUSTRIES, GROUPE HERSTAL, MBDA, RHEINMETALL AG...

Research Centers

CEA DAPNIA, CENAERO, CIAM, CNR Itia , CNRS/IN2P3, EADS-CCR, ONERA…

SAMTECH HeadquartersLIEGE science parkRue des Chasseurs-Ardennais, 8B-4031 Angleur-Liège, BelgiumTel. : +32 4 361 69 69Fax : +32 4 361 69 80http://www.samcef.com

SAMTECH DeutschlandTempowerkring 6D-21079 Hamburg, GermanyTel. : +49 40 79012 320Fax : +49 40 79012 321

SAMTECH FranceParis

14, avenue du QuébecBât. K 2.1, SILIC 618

Villebon-sur-YvetteF-91945 Courtabœuf Cedex, FranceTel. : +33 1 69 59 22 80Fax : +33 1 64 46 29 65Toulouse

11, rue Marius TerceF-31300 Toulouse, FranceTel. : +33 5 34 55 20 99Fax : +33 5 34 55 15 00

SAMTECH Italia

Via Guido d’Arezzo, 4I-20145 Milano, ItalyTel. : +39 02 48 559 407

Fax : +39 02 46 94 998

SAMTECH Iberica

C/Codonyer 8-10E-08017 Barcelona, SpainTel. : +34 932 802 439Fax : +34 932 802 439

SAMTECH UK

Trym Lodge1 Henbury RoadWestbury-on-TrimBristol BS9 3HQ, England

Tel. : +44 117 959 65 00Fax : +44 117 959 65 01

Samcef Rotor

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