Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
DESIGN OPTIMIZATION OF A STOCHASTIC DYNAMIC PLATE BASED ON FATIGUE LIFE
Submission Author:
Ulisses Lima Rosa , MG
Co-Authors:
Ulisses Lima Rosa, Lauren Karoline Sousa Gonçalves, Antonio Marcos de Lima
Presenter: Ulisses Lima Rosa
doi://10.26678/ABCM.COBEM2019.COB2019-0792
Abstract
This work presents an optimization strategy to increase and evaluate fatigue life of a dynamic structure subjected to uncertainties in its geometry and loads. The main objective is to reduce thickness of an aluminum plate, which is directly in conflict with enhancing its durability when subjected to cyclic loads. Solving this multiobjective problem requires the application of metaheuristic methods, searching not only one point in the search space, but a whole group of solutions where all are treated as optimal. The chosen technique which was applied in the numerical simulations is the NSGA (Non-Dominated Sorting Genetic Algorithm). As the system is stochastic, this approach presents, in general, high sensitivity to small changes or fluctuations in the variables of interest. This can abruptly affect the objective functions in the region close to a global optimum. A robust method is applied herein and is compared with previous results, highlighting that, despite the robust optimum may not always be the global optimum, structural randomness makes this type of analysis necessary to ensure reliability. Numerical results are presented in terms of FRF, stress responses in the frequency domain and Sines fatigue index for each finite element composing the plate.
Keywords
stochastic finite elements method, fatigue, Robust optimization, Random vibrations
