An improved nonintrusive global-local approach for sharp thermal gradients in a standard FEA platform

Several classes of important engineering problems-in this case, problems exhibiting sharp thermal gradients-have solution features spanning multiple spatial scales and, therefore, necessitate advanced hp finite element discretizations. Although hp-FEM is unavailable off-the-shelf in many predominant commercial analysis software packages, the authors herein propose a novel method to introduce these capabilities via a generalized FEM nonintrusively in a standard finite element analysis (FEA) platform. The methodology is demonstrated on two verification problems as well as a representative, industrial-scale problem. Numerical results show that the techniques utilized allow for accurate resolution of localized thermal features on structural-scale meshes without hp-adaptivity or the ability to account for complex and very localized loads in the FEA code itself. This methodology enables the user to take advantage of all the benefits of both hp-FEM discretizations and the appealing features of many available computer-aided engineering /FEA software packages to obtain optimal convergence for challenging multiscale problems.