Open Access

ARTICLE

An Anisotropic Damage Model for the Evaluation of Load Carrying Capacity of Composite Artificial Ligaments

by P. Vena¹, R. Contro

1 Laboratory of Biological Structure Mechanics Department of Structural Engineering Politecnico di Milano Piazza Leonardo da Vinci, 32 – 20133 Milano – Italy

Computer Modeling in Engineering & Sciences 2003, 4(3&4), 497-506. https://doi.org/10.3970/cmes.2003.004.497

Abstract

The adoption of artificial ligaments in current surgery is still characterised by a low success rate due to the fact that mechanical properties of the biomedical devices are such that a biomechanical compatibility is not fully satisfied. A durable artificial ligament should exhibit stiffness as well as strength properties which are such that a full articulation functionality is guaranteed. To this purpose, reliable numerical methods able to predict the mechanical behaviour of such devices both in the elastic and in inelastic range until complete rupture, could be used for designing of devices with tailored mechanical properties.

The present paper deals with the mechanical characterisation of artificial ligaments made of composite materials, with specific reference to the tensile load carrying capacity. The artificial ligaments taken into consideration are composite cylinders which are manufactured by reinforcing a compliant matrix by means of helicoidally oriented fibres. A finite strain model has been developed and characterised by a stiffness degradation of the reinforcing fibres playing the prominent mechanical role. A suitable choice of the constitutive parameters allowed to reproduce the elastic behaviour and to catch the limit load experimentally measured.

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