Skip to main navigationSkip to main content
The University of Southampton
Institute for Life Sciences

Bioengineering Seminar: Microstuctural models of ligament and tendon elasticity and viscoelasticity Event

Time:
11:00 - 12:00
Date:
15 January 2016
Venue:
University of Southampton, Highfield Campus, Building 07, Room 3027.

For more information regarding this event, please email Dario Carugo at D.Carugo@soton.ac.uk .

Event details

Ligaments and tendons are fundamental structures in the musculoskeletal systems of vertebrates. In this talk, we will discuss two models that describe the mechanical behaviour of ligaments and tendons.

Ligaments connect bone to bone to provide stability and allow joints to function correctly, whereas tendons connect bone to muscle to allow the transfer of forces generated by muscles to the skeleton. The wide variety of roles played by different ligaments and tendons requires them to have considerably different mechanical responses to applied forces, and their differing stress-strain behaviours have been well documented. Ligaments and tendons consist of collagenous fibres organised in a hierarchical structure. Their main subunit is the fascicle which consists of fibrils arranged in a crimped pattern. The first model is a non-linear elastic model, which is expected to be valid in the low strain-rate limit, where hysteresis is minimised. We will derive a new strain energy function for modelling ligaments and tendons based on the geometrical arrangement of their fibrils (which are individually assumed to be linear elastic), and will compare the ability of the new model to reproduce experimental data with that of the commonly used Holzapfel-Gasser-Ogden (HGO) model. We will show that the new model gives a better fit to stress-strain data for human patellar tendon than the HGO model, with the average relative error when using the new model being 0.053 (compared with 0.57 when using the HGO model), and the average absolute error when using the new model being 0.12MPa (compared with 0.31MPa when using the HGO model). The second model is a viscoelastic model. By assuming that each fibril is now linearly viscoelastic, we will show that several complex, non-linear viscoelastic effects can be explained solely by the distribution of the fibril crimp lengths. The viscoelastic model also shows excellent agreement with experimental data, and can reproduce different data sets with the same set of constitutive parameters simply by changing the distribution of the crimp lengths.

Speaker information

Dr Tom Shearer and Dr William J. Parnell,School of Mathematics, University of Manchester ,Visiting speakers

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×