Stochastic model updating considering thermal effect using perturbation and improved support vector regression

The dynamic modeling of structures in a thermal environment has become a new research topic in structural dynamics. Uncertainties caused by noise or material variability increase the difficulty in structural dynamic modeling when considering thermal effects. In this study, a finite element (FE) model updating approach is proposed that includes thermal effects and uncertainties by using a hierarchical strategy. First, the dynamic problem of a structure in a thermal environment is classified into a thermal model and a structural dynamic model, and they are both constructed by using the FE method. As a result, the model updating process is conducted for both the thermal model and structural dynamic model. Different from other works about model updating methods, the updating variables, which are composed of the mechanical characteristics and thermal parameters of the system, are dominated by the temperature distribution of the structure under study. A perturbation method and a surrogate model are adopted in the stochastic model updating approach to make the updating process highly efficient. Finally, the proposed method is validated by updating the model of a fuselage skin and a bolt connection beam in a thermal environment.