Constitutive models for biodegradable thermoplastic ropes for ligament repair

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Andre C Vieira (Author) FEUP; Rui M Guedes (Author) FEUP; Volnei Tita (Author) Other

Journal

Title: Composite Structures

Vol. 94 No. 11

Pages: 3149-3159

ISSN: 0263-8223

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 7 Citations

Scopus - 8 Citations

Scientific classification

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: P-002-4AE

DOI: 10.1016/j.compstruct.2012.05.010

Abstract (EN): The concept behind a biodegradable ligament device is to temporarily replace the biomechanical functions of the ruptured ligament, while it progressively regenerates its capacities. However, there is a lack of methods to predict the mechanical behaviour evolution of the biodegradable devices during degradation, which is an important aspect of the project. In this work, a hyper elastic constitutive model will be used to predict the mechanical behaviour of a biodegradable rope made of aliphatic polyesters. A numerical approach using ABAQUS is presented, where the material parameters of the model proposal are automatically updated in correspondence to the degradation time, by means of a script in PYTHON. In this method we also use a User Material subroutine (UMAT) to apply a failure criterion base on the strength that decreases according to a first order differential equation. The parameterization of the material model proposal for different degradation times were achieved by fitting the theoretical curves with the experimental data of tensile tests on fibres. To model all the rope behaviour we had considered one step of homogenisation considering the fibres architectures in an elementary volume.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11