A new strain energy function for modelling ligaments and tendons whose fascicles have a helical arrangement of fibrils

Shearer, Tom (2015) A new strain energy function for modelling ligaments and tendons whose fascicles have a helical arrangement of fibrils. Journal of Biomechanics, 48. pp. 3017-3025. ISSN 0021-9290

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Abstract

A new strain energy function for the hyperelastic modelling of ligaments and tendons whose fascicles have a helical arrangement of fibrils is derived. The stress-strain response of a single fascicle whose fibrils exhibit varying levels of crimp throughout its radius is calculated and used to determine the form of the strain energy function. The new constitutive law is used to model uniaxial extension test data for human patellar tendon and is shown to provide an excellent fit, with the average relative error being 9.8%. It is then used to model shear and predicts that the stresses required to shear a tendon are much smaller than those required to uniaxially stretch it to the same strain level. Finally, the strain energy function is used to model ligaments and tendons whose fascicles are helical, and the relative effects of the fibril helix angle, the fascicle helix angle and the fibril crimp variable are compared. It is shown that they all have a significant effect; the fibril crimp variable governs the non-linearity of the stress-strain curve, whereas the helix angles primarily affect its stiffness. Smaller values of the helix angles lead to stiffer tendons; therefore, the model predicts that one would expect to see fewer helical sub-structures in stiff positional tendons, and more in those that are required to be more flexible.

Item Type:	Article
Uncontrolled Keywords:	Ligaments Tendons Strain energy function Helically arranged fibrils Crimp
Subjects:	MSC 2010, the AMS's Mathematics Subject Classification > 74 Mechanics of deformable solids MSC 2010, the AMS's Mathematics Subject Classification > 92 Biology and other natural sciences PACS 2010, the AIP's Physics and Astronomy Classification Scheme > 40 ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID MECHANICS > 46 Continuum mechanics of solids
Depositing User:	Dr Tom Shearer
Date Deposited:	02 Oct 2015
Last Modified:	20 Oct 2017 14:13
URI:	https://eprints.maths.manchester.ac.uk/id/eprint/2395

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• A new strain energy function for modelling ligaments and tendons whose fascicles have a helical arrangement of fibrils. (deposited 18 Aug 2015)
  • A new strain energy function for modelling ligaments and tendons whose fascicles have a helical arrangement of fibrils. (deposited 02 Oct 2015) [Currently Displayed]

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