Fully coupled thermo-mechanical analysis of bi-directional FGM beams using NURBS isogeometric finite element approach

The fully coupled thermo-mechanical behavior of bi-directional functionally graded material (FGM) beam structures is studied using a computationally low cost isogeometric finite element model. In the proposed analysis, the temperature is considered as a primary variable. The kinematical equations of the bi-directional FGM beam are described by a refined high order global-local theory. A combination of polynomial and exponential expressions is used to introduce the in-plane displacement field. This representation of the in-plane displacement field allows avoiding shear correction factors. Concerning the thermal part, a high-order temperature field is considered through the thickness direction of the bi-directional graded beam. The capability of this novel formulation has been assessed through various thermal and thermo-mechanical tests. To this aim, the obtained numerical results from the proposed isogeometric formulation have been compared with thermo-elasticity solutions or other available results in open literature. It is found that the results obtained from the present beam formulation agree quite well with the reference results.