Detection and identification of nonlinearities in aeroelastic systems

• Grant number: 12/14273-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2012
• End date: February 28, 2013
• Field of knowledge: Engineering - Aerospace Engineering
• Principal Investigator: Flávio Donizeti Marques
• Grantee: Rui Marcos Grombone de Vasconcellos
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Characterization of nonlinearities in aircraft is critical to the solution of aeroelastic problems where an optimal relation between performance and safety is desirable. Aeroelastic systems are inherently nonlinear. Nonlinearities can be admitted in the project, or may arise at any time during the life of the aircraft, significantly affecting the predicted response by conventional methods of linear analysis and reducing the limits for catastrophic instabilities. Therefore, it is important to characterize, identify and include such non-linear effects to the design and development of aircraft. In this research proposal, through nonlinear time series analysis and identification techniques, a method for the detection, identification and characterization of structural and aerodynamic nonlinearities in aeroelastic systems using an experimental database is proposed. Characteristics of each type of nonlinearities, from structural and aerodynamic sources are determined and verified by using a mathematical model and nonlinear time series analysis techniques. The results are the basis for the analysis of nonlinear experimental data. A nonlinear identified mathematical model for the experimentally observed dynamics, using the proposed methodology is obtained, in order to incorporate the nonlinear effects presented. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VASCONCELLOS, R.; ABDELKEFI, A.. Phenomena and characterization of grazing-sliding bifurcations in aeroelastic systems with discontinuous impact effects. Journal of Sound and Vibration, v. 358, p. 315-323, DEC 8 2015. (12/14273-6)

VASCONCELLOS, RUI; ABDELKEFI, ABDESSATTAR. Nonlinear dynamical analysis of an aeroelastic system with multi-segmented moment in the pitch degree-of-freedom. COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION, v. 20, n. 1, p. 324-334, JAN 2015. (12/14273-6)

VASCONCELLOS, R.; ABDELKEFI, A.; HAJJ, M. R.; MARQUES, F. D.. Grazing bifurcation in aeroelastic systems with freeplay nonlinearity. COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION, v. 19, n. 5, p. 1611-1625, MAY 2014. (12/14273-6)