Simulation of the Behavior of a Cracked Head of Shoulder Prosthesis

The health safety of the human being is one of the most important goals of governments around the world. The cessation of the functioning of any organ of the human body would have a negative impact on psychological and physical health of the patient. The replacement of the damaged organ by an artificial organ is the used solution. The shoulder joint is an example; a total prosthesis can be implanted to recover the functioning of the upper limb. The right choice of materials for this prosthesis is one of the research directions today. The purpose of this work is to predict the propagation of the crack previously created in the head of the shoulder prosthesis. Shoulder prosthesis is composed of two components: a head made usually of inoxydable steel or metallic alloys and a cup which could be made of UHMWPE. The proposed material of the head was alumina. As bioceramics, alumina has known properties that make it a candidate material to replace used stainless steel or metallic alloys. But fragility is the most undesirable alumina property. So to investigate its tenacity prior defects were created and to extend the investigation two cases of remarkable location of the prior crack were considered. The selected mean of simulation is the finite element calculation code Abaqus. The needed data: geometries of the two compounds of the shoulder prosthesis, loads and mechanical properties of the considered material were implemented. The obtained results concerned normal stresses at the tip and the line of propagation of prior cracks. The calculation of intensity stress factor is necessary to judge alumina tenacity. Final results in the two cases reveal the possibility of using alumina as a material of the humeral insert.