On the Extension-Torsion of Short Hyperelastic Tubes of Axially Functionally-Graded Materials

Abstract

The mechanical behavior of thick-walled tubes made of axially functionally graded (FG) incompressible nonlinear elastic materials under combined extension-torsion loading is focused on in this study. To achieve more realistic modeling, a computation-efficient semi-analytical approach is proposed, which is subsequently validated through finite element simulations. Axially functional grading is addressed by considering finite length instead of the commonly assumed infinite length. Additionally, a comparative study is conducted to examine twelve different functional grading distributions based on silicon-rubber Neo-Hookean material constant. 3D numerical simulations are outperformed by our approach by up to 50 times in computational efficiency under identical hardware conditions. The results indicate the model's capability to evaluate the non-linear distribution of twisting along the length, also stress analysis suggests that decreased shear stress variation, reaction torque, and force can be achieved by increasing the material gradient in larger than one composition ratio. Overall, valuable insights for engineers are provided by our approach, ensuring structural integrity and safe operation of functionally graded cylindrical components in various engineering applications.