Influence of microstructural characteristic torsion length on exponentially graded cylinders in torsion

This paper presents a finite element model for an exponentially graded, isotropic, Cosserat elastic material. The presented research focuses on conducting a parametric study to investigate the influence of the torsional characteristic length on the torsional properties of cylinders in pure torsion, with exponential grading along the axis of the cylinders. A mesh sensitivity study is performed, as well as a study on the influence of the mentioned functional grading on the torsional properties of the cylinders. Lastly, an investigation into the influence of the torsional characteristic length and specimen size (cylinder diameter) is performed to confirm the presence of a size effect, commonly discussed in the literature. The findings of the studies are presented, along with their implications.