Structural mechanics

Helicoidal modeling

The helicoidal modeling was applied to continuum mechanics by Prof. Teodoro Merlini and me. The angular equilibrium equations at a point are written with respect to a fixed pole, and not with respect to the point itself; as a consequence, the angular equilibrium equations take the same structure of the linear equilibrum equations.
The kinematic description is peculiar as well: it is based on the concept of rototranslation, a motion that intimately couples displacements and rotations of the materal particle of any micropolar medium.
The proposed formalism was first applied to the modeling of non-structured continua, and then to the modeling of beams and shells. The resulting finite elements, developed without resorting to EAS and/or ANS techniques, show remarkable properties and appears to be free from locking phenomena.
List of publications
Films: Brick elements simulations Shell elements simulations

Beams

The elastic properties of composite beam sections can be computed numerically. A well-established numerical procedure has been recently enhanced and clarified by me, Maria Chierichetti and Prof. Paolo Mantegazza. A generalization to beams made of piezo-electric materials is available as well. The current research involves the extension to non-linear problems and to initially curved beams. The development of enhanced beam FEs based on the more recent results is envisaged as well.
The same characterization procedure has been extensively used for the structural optimization of beam sections. Excellent results has been obtained, in cooperation with Prof. Pierangelo Masarati, for the optimization of helicopter rotor beams actively twisted using piezo patches.
List of publications

Shells

Work on shells has been focused so far on the development of an helicoidal shell element. Future work will be focused on shell constitutive law characterization procedures.
A specialized nonlinear shell element has been developed within the mutibody code MBDyn. It is currently used, coupling MBDyn with different CFD codes, in order to investigate the dynamic behavior of flapping-wing insect-like robots.

Multibody

Activities on Multibody Modeling is focused on the developement of new, advanced joint elements, on the consistent treatment of rotations and on algorithmic issues. The invariant deformable and the gimbal are perhaps the more complex joints among those developed so far.
List of publications

Landing Gears

List of publications

Modeling and control of active telescopes

Accurate modeling of active telescope mirrors is of paramount importance for a reliable and precise prediction of their dynamic. The simulation model developed together with Prof. Paolo Mantegazza and Mauro Manetti correctly reproduces
  • the effect of the thin fluid film (few micrometers) interposed between the mirror and its underlying reference structure;
  • the effect of the position sensor finite dimensions;
  • the position sensor and actuator transfer function.
The simulation model leads to excellent experimental-numerical correlations; this allows to assess the performance and robustness of new, advanced mirror control law that are being developed.
List of publications

Structural Optimization

List of publications

Computational mechanics