Some numerical assessments on intergranular crack propagation in polycrystals. Application to -TiAl D. Geoffroy 1,2 , J. Crépin 2 , E. Héripré 3 , A. Roos 1 1 DMSM/MNU, ONERA, France 2 Centre des Matériaux, MINES-ParisTech UMR CNRS 7633, France 3 LMS, Ecole Polytechnique ParisTech UMR CNRS 7649, France dominique.geoffroy@onera.fr ABSTRACT This work presents a numerical study of the intergranular crack propagation behavior of -TiAl. For this purpose, finite element simulations using remeshing techniques and crystal plasticity are carried out on a bidimensional -TiAl polycrystal. In order to evaluate the influence of crystal orientations, ten different random orientations are generated and used on the same finite element polycrystal mesh. First the force- displacement curves are analysed to show that the crystal orientations influence significantly the material’s global response. Then, the paths taken by the crack in the different polycrystals are investigated, but they show that crystal orientations do not seem to have a great influence on them. INTRODUCTION The thrust-to-weight ratio has always been a crucial criterion in the design of aircraft engines because of its influence on the turbine's efficiency and gas consumption. Since an important part of the aircraft weight is in the engine, many studies have been carried out in order to find new materials for that specific application. Among them, titanium aluminides seem very promising because of their excellent properties at high temperatures. However, the widespread use of this material is still quite limited by its low fracture thoughness at room temperature and its mechanical properties' high sensitivity on the microstructure. Hence, the microstructural properties need to be taken into account when investigating its mechanical response. Many studies have been carried out on these alloys during the last decades [1, 2, 3]. Among them, Héripré et al. [4] developed a coupling method between numerical simulations and experimental studies to identify the parameters of the crystal plasticity constitutive law. Finite element (FE) simulations can now be conducted on this material, as done by Héripré [5], Kabir et al. [6], Roos et al. [7] and Roters et al. [8]. Also, Simkin et al. [9] showed that the crack initiation and propagation in -TiAl was 799