Abstract

MARINELLI, Franco; WEISS, Brenda A.; BERLI, Marcelo E.  and  DI PAOLO, José. EQUIVALENT ELASTIC MODULUS FOR PREDICTION OF DEFORMATIONS IN JOINTS. Ingenius [online]. 2018, n.20, pp.70-82. ISSN 1390-860X.  https://doi.org/10.17163/ings.n20.2018.07.

When studying human joints contact mechanics, the surfaces deformations are relevant as they enable a lubrication flow channel that reduces wear. In order to determine the validity of different methods to predict the surfaces displacements, they were applied to the dry and static contact of healthy and prosthetic joints, both for knee and hip joints. Three equivalent elastic modulus for a simplified column model were evaluated: elastic modulus for a layer solid, elastic modulus for a semi-infinite solid (or Winkler elastic modulus) and elastic modulus for a corrected semi-infinite solid. A hertzian load was considered for all cases. The results were compared with the solution of the elasticity equations by means of the finite element method (FEM). The results for the Young´s modulus, corresponding to a material as a layer, are those that best approximate the FEM prediction. It is also shown that the Young´s module derived from the semi-infinite approximation are inappropriate. Likewise, this work allowed the training of an undergraduate student in Computational Mechanics.

Keywords : finite element; hip joint; knee joint; lineal contact; lubrication; punctual contact.

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