Fatigue Analysis of Viscoelastically Damped Structures Subjected to Uncertainties
Ulisses Lima Rosa1; Lauren Karoline de Sousa Gonçalves1; Antônio Marcos Gonçalves de Lima1
1 Universidade Federal de Uberlândia
doi:10.20906/CPS/CILAMCE2017-0705
Resumo
In the scope of structural dynamics, in most of the cases, engineering systems are evaluated by considering mean values of their physical and geometrical properties. However, based on the fact that real-word engineering systems are subjected to uncertainties, deterministic approaches may not represent with reasonable accuracy the real dynamic behavior of the structures such as in fatigue failure induced by mechanical vibrations. As a result, it can lead to a catastrophic failure, depending on the application. Thus, in order to provide a more realistic study of this subject, structural characterization requires the application of statistical methods, considering fluctuation of design variables such as elastic modulus, thickness and temperature. After the presentation of the theoretical foundations, numerical studies are performed with a sandwich thin plate system incorporating viscoelastic damping. The interest is to investigate the influence of the uncertainties and to perform a sensitivity analysis for the three-layer sandwich plate structure treated with passive constrained damping layer under Gaussian random loadings. In this case, the influence of the parametric uncertainties on the stress responses and the fatigue index are performed by means of the well-known Latin Hypercube Sampling (LHS). Numerical results are presented in terms of frequency responses functions (FRFs), stress responses (PSDs) and fatigue indexes estimated by Sines' criterion. Based on the obtained results, it is possible to highlight the importance of considering the effects of uncertainties in the fatigue analysis of more realistic situations.
Palavras-chave: Non-parametric uncertainties; Viscoelastic Damping; Fatigue; Finite Elements Method; Dynamics