Higher Edu - Research dev card
Development from the higher education and research community
  • Creation or important update: 25/11/11
  • Minor correction: 25/11/11

MULTIROTOR : prediction of the dynamic behavior of multirotors

This software was developed (or is under development) within the higher education and research community. Its stability can vary (see fields below) and its working state is not guaranteed.
  • System: Windows
  • Current version: March 2010
  • License(s): Proprietary licence
  • Status: stable release
  • Support: maintained, ongoing development
  • Designer(s): Guy FERRARIS, Michel LALANNE
  • Contact designer(s):
  • Laboratory, service: LaMCoS


General software features

This finite element software is devoted to the prediction of the dynamic behavior of parallel multirotors in bending.
Node: 4 degrees of freedom.
Shaft: two-node beam element, classical stiffness and mass matrices, axial forces, shear, rotatory inertia and gyroscopic effect are taken into account.
Disk: one-node disk element, rigid, defined by mass and gyroscopic matrices effects.
Bearings: stiffness and damping matrices which can be non-symmetric and can vary as a function of the speed of rotation.
Specific elements: modeling of particular effects such as couplings, magnetic attraction, stator …

MULTIROTOR predicts:
In Statics:
- The deflection of the shafts subjected to gravity and/or forces which can be concentrated.

In Dynamics:
- Natural frequencies and modes in rotation, Campbell diagram, instabilities and damping factors.
- Mass unbalance response, asynchronous force response, response to a harmonic force fixed in space.
- Maximum stresses in the shafts, loads on bearings.
- Elementary energies, kinetic and strain energies in elements.

Context in which the software is used

MULTIROTOR is used for rotating machinery design, especially for jet engines and for the modification of the architecture of existing machines.
MULTIROTOR is used for training at INSA-Lyon, in France and in foreign countries.

The expertise of the laboratory has been greatly gained from contracts with companies and state organizations over a period of nearly 30 years.

Publications related to the software

The software is based on the theory presented in:
1. Prédiction du comportement dynamique des moteurs d’avion : vitesses critiques, effets de balourd. Patrick Berthier, Guy Ferraris, Michel Lalanne. J. Mec.Th. et Appl, 5. 1986.
2. Prediction of the dynamic behavior of non-symmetric coaxial co-or counter rotating rotors .G Ferraris, V.Maisonneuve , M.Lalanne. J of Sound and Vibration 1996 195(4), 649-666.
3. Rotordynamics Prediction in Engineering by Michel Lalanne and Guy Ferraris. J. Wiley, 254 p, 2nd edition 1998. ISBN 0 471 97288 6
4. Dynamique des rotors en flexion. Guy Ferraris, Michel Lalanne. Techniques de l’ingénieur Traité Génie Mécanique, B5 110, 1996.