Sajjad Ganji Zadeh

Grade:  Master

Thesis Title:

Finite Element Analysis for Fatigue Loading of Hybrid Material Using Damage Mechanics

Year: Sept. 2016- Jun. 2019.

Abstract:

Hybrid materials are known as a group of composites that consist of an organic and an inorganic parts. In medical science, hybrid materials are used for the replacement of damaged tissues such as bone prostheses. Hybrid material bone prostheses can be absorbed by body and the new bone tissue replaces the said bone prostheses whilst exhibiting properties similar to those shown by the body bone tissue. As bone prostheses are subjected to cyclic loadings as result of one's physical activities, in this research the fatigue behavior of the hybrid material prosthesis is discussed. The Ogden hyperelastic constitutive equation is used to model the mechanical behavior of bone prostheses. Employing continuum damage mechanics approach, the Ogden hyperlastic model with the Lemaitre-Chaboche damage model was implemented by a VUMAT subroutine in Abaqus software. To investigate the fatigue behavior of bone prosthesis, a representative volume element (RVE) simulation is performed. The RVE geometry is created by spherical pores and random arrangement through a script implemented in the python environment of the Abaqus software. The simulation results of fatigue behavior of this RVE are compared with the experimental data achieved from the fatigue tests of porous bone tissue. Also, the ability of bone prostheses as a replacement for the porous bone tissue is evaluated. The simulation results demonstrated that the hybrid material introduced in fatigue loading exhibit a longer life about 45 percent than the porous bone tissue, and also represents a softer behavior.

Keywords:  Hybrid materials, Hyperelastic, Fatigue, Continuum damage.