Publications
RVE-BASED HOMOGENIZATION OF ADDITIVELY MANUFACTURED POROUS METALS
Autors: Alaimo, A., Mantegna, G., Orlando, C., Tumino, D. & Vindigni, C. R.
33RD Congress of the International Council of the Aeronautical Sciences (2022).
Abstract: Additive Manufacturing technologies have been extensively used in different industry sectors thanks to the optimisation of material waste, reduction of the high production costs and the ability to create components with complex geometric shapes and highly customisable mechanical performance. However, to fully exploit the benefits of these technologies, in-depth knowledge is needed on how internal defects condition the overall behaviour of the component. In this work, a Representative Volume Element like approach is presented to study, through different numerical analyses, the effect of size, number and spatial distribution of micro-voids on the stress-strain behaviour of Selective Laser Melting additive manufactured AlSi10Mg. An in-house code on the commercial software ANSYS Parametric Design Language APDL is used to model a random pore distribution inside the RVE in compliance with statistical distribution retrieved from the literature; comparison with reference case studies are reported.
AN AEROELASTIC BEAM FINITE ELEMENT FOR TIME DOMAIN PRELIMINARY AEROELASTIC ANALYSIS
Autors: Vindigni, C. R., Mantegna, G., Esposito, A., Orlando, C., & Alaimo, A. (2022)
Mechanics of Advanced Materials and Structures, 30(5), 1064–1072. https://doi.org/10.1080/15376494.2022.2124333
Abstract: An aeroelastic beam finite element based on Euler-Bernoulli beam theory and two-dimensional unsteady aerodynamics is presented. Based on the flexural-torsional equations of motion of the wing the finite element formulation is provided by means of their weak form, taking into account the presence of trailing edge control surfaces that are considered flexible. Each aeroelastic beam presents transverse and rotation displacements due to bending and torsion of the wing box, torsion of the control surface, and the aerodynamic lag state. The developed finite element model is validated with literature and numerical flutter results of wings with and without control surfaces.
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SANDWICH HYBRID STRUCTURAL COMPONENT FOR TILT ROTOR AIRCRAFT
Autors: Mantegna, G., Vindigni, C. R., Tumino, D., Orlando, C., & Alaimo, A. (2023).
Aerospace Europe Conference 2023 – 10ᵀᴴ EUCASS – 9ᵀᴴ CEAS
Abstract: Sandwich structures have been increasingly used due to their high strength-to-weight ratio and bending and buckling resistance. Today, it is possible to create topology-optimised structures with complex shapes using lattice structures through Additive Manufacturing technologies, avoiding the difficulties in core sheets adhesion in sandwich structures. In this paper, a 3D numerical model is proposed to assess the mechanical properties of hybrid lattice structures. A comparison between the overall response of a control surface of a tiltrotor aircraft with different cores for its sandwich panels will be studied. Specifically, two strut lattice cores and a conventional honeycomb lattice core are considered as options for the asymmetric sandwich panels.
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A 3D AEROELASTIC BEAM MODELLING APPROACH FOR TIME DOMAIN NON-UNIFORM LIFTING STRUCTURES FLUTTER ANALYSIS
Autors: Vindigni, C. R., Mantegna, G., Orlando, C., & Alaimo, A. (2023).
Aerospace Europe Conference 2023 – 10ᵀᴴ EUCASS – 9ᵀᴴ CEAS
Abstract: In this work an alternative 3-dimensional aeroelastic beam finite element for rapid time-domain flutter analysis of non-uniform wings equipped with distributed trailing edge control surfaces is presented. The approach proposed takes advantage of Euler-Bernoulli and De Saint Venant beam theories. The aerody namic loads, expressed in time domain, are directly incorporated in the beam element matrices that are computed from the governing equations weak form, resulting in a simple numerical tool that can be easily implemented in any beam-based finite element code. The method proposed is validated with commercial code aeroelastic results of non-uniform lifting structures with and without control surfaces.
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MECHANICAL PROPERTIES OF BCC LATTICE CELLS WITH WAVED STRUTS
Autors: Tumino, D., Alaimo, A., Mantegna, G., Orlando, C., & Valvano, S. (2023).
International Journal on Interactive Design and Manufacturing (IJIDeM), 1-14.
​https://doi.org/10.1007/s12008-023-01359-9
Abstract: In this paper, the mechanical properties of a modified Body-Centred Cubic lattice cell with waved struts have been determined using FEM simulations with solid element mesh. The strut waviness introduces orthotropic properties in the cell and the correlation between geometrical cell parameters and resulting mechanical attitudes is calculated. For a complete determination of all the mechanical constants, uniaxial compression and in-plane shear have been simulated along different loading directions. Attention has been particularly paid to the definition of appropriate boundary constraints able to mimic the periodic condition that applies to a repetitive unit cell. At first, the numerical model has been validated with existing analytical and experimental results available in the literature, then parametric strut waviness has been introduced to this model. A systematic numerical study has been conducted on lattice cells with different density and different wave amplitude. Results have evidenced for the waved struts a considerable increase in the longitudinal uniaxial modulus and a negligible effect on the transverse moduli, while a slight reduction of the shear moduli is generally obtained in all the sliding planes. Poisson’s ratios are highly affected both by density and waviness. The obtained results can be useful for the optimized definition of a lattice cell, tailored to the specific mechanical requirements of an advanced component.
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COMPARISON OF LATTICE CORE TOPOLOGIES IN SANDWICH STRUCTURES
Autors: Mantegna, G., Vindigni, C. R., Tumino, D., Orlando, C., & Alaimo, A. (2023).
Aeronautics and Astronautics, AIDAA XXVII International Congress
Materials Research Proceedings, 37.
Abstract: Hybrid sandwich structures are often used in the aviation industry thanks to their high strength-to-weight ratio and resistance to bending and buckling. Today, through Additive Manufacturing technologies, it is possible to use different materials to create topology-optimized structures with complex shapes using lattice structures. In this work, a numerical approach is proposed to study the behaviour of a hybrid sandwich structure which can be used as a reinforcement for a control surface of a lightweight aircraft. A comparative analysis is conducted between a conventional honeycomb lattice core and lattice truss core structures.
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SIMPLE ADAPTIVE WING-AILERON FLUTTER SUPPRESSION SYSTEM
Autors: Vindigni, C. R., Mantegna, G., Orlando, C., & Alaimo, A. (2024).
Journal of Sound and Vibration, 570, 118151.
https://doi.org/10.1016/j.jsv.2023.118151
Abstract: In this work a simple adaptive flutter suppression system is designed in order to increase the operative speed range of a wing-aileron aeroelastic plant. The equivalent beam finite element based aeroelastic modeling of a wing equipped with a trailing edge aileron in incompressible flow is presented and its state space representation is provided. The almost strictly passivity of the plant is assured by means of a parallel feed-forward compensator implementation and the invariant controller parameters are tuned using a population decline swarm optimization algorithm that minimize the integral of the time absolute error on the wing tip torsion angle. The performance of the closed loop system are studied carrying out numerical simulations that reproduce different flight scenarios with the presence of speed variations, disturbances, and gusts proving the effectiveness of the proposed simple adaptive flutter suppression architecture.
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STOCHASTIC ROBUSTNESS ANALYSIS OF WING-AILERON FLUTTER SUPPRESSION SYSTEMS
Autors: Vindigni, C. R., Mantegna, G., Esposito, A., Orlando, C., & Alaimo, A. (2024, May).
In Journal of Physics: Conference Series (Vol. 2746, No. 1, p. 012007). IOP Publishing.
Abstract: In this work a stochastic robustness analysis approach is used to compare the performances of two non-linear flutter suppression systems designed for stabilization of a wing-aileron lifting structure. A reduced order modelling approach based on an alternative aeroelastic beam finite element is presented and used for the flutter suppression systems design, which are driven by a simple adaptive controller and a sliding mode controller, respectively. A heuristic algorithm is used to determine the simple adaptive controller invariant parameters at the design point while a simple parametric study is performed to tune the sliding mode controller. The performances of each closed loop system are evaluated taking into account mass, stiffnesses, and aerodynamics uncertainties of the aeroelastic plant also considering the presence of discrete gust disturbances.
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WING-AILERON ADAPTIVE FLUTTER SUPPRESSION SYSTEM
Autors: Vindigni, C. R., Orlando, C., Esposito, A., & Alaimo, A.
Materials Research Proceedings, 42.
Abstract: In this work a flutter suppression system design based on simple adaptive control architecture and an alternative beam finite element modelling of wings equipped with trailing edge control surfaces is proposed. The aeroelastic beam finite element used is based on Euler-Bernoulli beam theory for the flexural behavior, De Saint Venant theory for torsion and two-dimensional time-domain unsteady aerodynamics applied by means of strip theory assumptions. The finite element modeling used allows to write the aero-servo-elastic plant governing equations in state-space form, from which the flutter suppression system design can be carried out in a time domain fashion. The simple adaptive control architecture has been applied to the aero-servo-elastic plant which passivity requirement has been enforced implementing a parallel feed-forward compensator.
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ADAPTIVE WING FLUTTER SUPPRESSION BY MEANS OF MULTIPLE TRAILING EDGE CONTROL SURFACES - A COMPARATIVE STUDY
Autors: Vindigni, C. R., Mantegna, G., Esposito, A., Orlando, C., & Alaimo, A. (2024).
34th Congress of the International Council of the Aeronautical Sciences
Abstract: In this work the employment of multiple control surfaces for adaptive flutter suppression systems design of wings is addressed. The aeroelastic plant is modeled taking advantage of an aeroelastic beam finite element framework that relies on an equivalent beam idealisation of the structure and strip theory aerodynamics, in cluding the dynamics of trailing edge control surfaces. A simple adaptive control architecture is employed to realize the flutter suppression systems and the passivity requirement of the aeroelastic plant is ensured by a parallel feedforward compensator implementation. Single and double aileron based flutter suppression sys tems are investigated and their performance are compared in terms of flutter boundary extension with respect to the open loop case.
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