FFT-based approach for dynamic response prediction of non-periodic systems
Combined experimental and numerical model updating approach for stress prediction in rotating components
A combined numerical and experimental approach named Confluence Algorithm has been developed to predict the dynamic response of rotorcraft dynamic components when only minimal experimental data are available. The confluence algorithm systematically updates the numerical model of the external loads, mass and stiffness distributions to best represent the experimental data and to extract information on the map of the response of the system at non-measured locations. The integration of experimental measurements into a numerical algorithm allows a continuous and accurate tracking of the dynamic strain and stress fields of each component without requiring detailed initial models. Specific algorithms have been developed for the updating of external loads and of physical properties of a periodic system. They can be separately applied when one of the sources of inaccuracy is predominant, or used in combination to solve a more general problem. The confluence algorithm aims to combine them into a unique, global approach. The identification procedure has potential practical use on usage health and monitoring systems and can contribute to improve the safety of rotorcraft flight and to decrease the handling costs of helicopters.
Modeling of anisotropic beams
Elastic, anisotropic, non-homogeneous, prismatic beams are solved with a semi-analytical formulation which separates the motion into a cross sectional and a beamwise component. The resulting variational formulation is solved with a finite element discretization over the cross-section, leading to a set of Hamiltonian ordinary differential equations along the span. Such a formulation is characterized by a group of generalized eigenvectors associated with null eigenvalues, which are shown to combine rigid body motions and the classical De Saint-Venant’s beam solutions. The generalized deformation are identified through the amplitude of the deformable generalized eigenvectors.
Structural design of seaplane floats
This project investigates the preliminary design of a seaplane float in fact have a great potential future market but their design and regulations are still obsolete so much so new floats made of composite materials needs to be designed with the use of modern technologies. The definition of the general arrangement of the float required the evaluation of preliminary parameter for the new float such as its shape, the number and volume of each watertight compartment. The heavy-load condition is identified as an alighting manouvre on water. Water loads are computed using Wagner Momentum Theory and a preliminary stress analysis is performed using monoque methods to define which materials are suitable for the structure and its mass distribution.