Interval finite element analysis of thermal protection system under thermomechanical coupling

Abstract

The uncertainty of thermal protection system (TPS) is inevitable in practical engineering. In this article, the interval finite element model of TPS is established by taking the uncertainties of TPS in thermomechanical coupling analysis as interval parameters. The perturbed-based interval finite element method (PIFEM) and affine-based interval finite element method (AIFEM) are proposed to study the displacement response of uncertain TPS under thermomechanical coupling. Two numerical examples are given and compared with Monte Carlo method (MCM) to verify the effectiveness and accuracy of the PIFEM and AIFEM proposed in this article. The results show that compared with the MCM, the computational efficiency of PIFEM and AIFEM is improved by more than three orders of magnitude, and the computational efficiency of PIFEM and AIFEM is similar. In the case of considering uncertain parameters, the conservative AIFEM is more suitable for the thermomechanical coupled uncertainty analysis of TPS. The numerical results provide useful guidance for TPS design.