Jose Augusto Ignacio da Silva

@poli.usp.br

Departament of Mechanical Engineering/Polytechnic School of the University of São Paulo
University of São Paulo

Jose Augusto Ignacio da Silva


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https://researchid.co/ignacio_15

EDUCATION

Doctor in Mechanical Engineering

RESEARCH, TEACHING, or OTHER INTERESTS

Mechanical Engineering, Modeling and Simulation, Computational Mechanics, Control and Systems Engineering

FUTURE PROJECTS

FAPESP 2025/09277-2: Dynamic Characterization of Hybrid Nonlinear Vibration Absorbers Based on Perturbation Methods: Application to Resonant and Self-excited Problems

Structural vibrations are present in various engineering problems, most of which can be classified as undesirable occurrences. High oscillation amplitudes and induced cyclic loading increase the likelihood of component failures. In this context, developing strategies to mitigate this behavior has been a major objective of the scientific community. Recently, the use of Nonlinear Energy Sinks (NES) has gained significant interest due to their ability to promote high attenuation of vibration amplitudes, coupled with their considerable robustness. NES consists of a vibration dynamic absorber with nonlinear characteristics. This research project focuses on proposing a hybrid NES, where an active feedback control element is integrated into the absorber's dynamics. The goal is to improve performance and overcome some limitations found in applications of conventional passive NES.


Applications Invited
Master's student Doctor''s student
1

Scopus Publications

Scopus Publications

  • On the controllers' design to stabilize ground resonance helicopter
    José A. Ignácio da Silva, Douglas D. Bueno, Gustavo L. C. M. de Abreu
    JVC Journal of Vibration and Control, 2019
    Ground resonance (GR) in helicopters is a potentially catastrophic instability commonly caused by coalescence of the regressive cyclic blade lag mode with the fuselage motion in certain rotor speed ranges. It can limit the helicopter operational envelope and the design of this type of vehicle can become a difficult task. Although a broad class of actuators allows the use of active and semi-active techniques to design feedback-based control systems, a limited number of works in the literature introduce formulations to compute the controller gain to suppress this phenomenon. Also, commonly, a control approach defines a feedback, particularly to a specific rotor speed. In this context, this work introduces an alternative methodology to design an active control system to stabilize GR of a helicopter. The proposed approach can suppress this instability in all rotor speed ranges by using only one control gain. Two strategies are proposed based on linear matrix inequalities (LMIs). The Lyapunov stability criteria are used and the unstable rotor speed is considered as an uncertain parameter to define an associated convex space. Using convex optimization, a robust control gain is computed until all the unstable rotor speed range is stabilized. Numerical simulations are carried out to demonstrate the effectiveness of this methodology. The results confirm the viability of the proposed approach to design active and semi-active controllers.