Prediction of the elastic strain limit of tendons

Prediction of the elastic strain limit of tendons

Reyes Lua, A.M.

Weinans, H.H. (mentor)
Zadpoor, A. (mentor)

Mechanical, Maritime and Materials Engineering

BioMechanical Engineering

BME

2012-11-22

The elastic strain limit of the tendon appears to be an omnipresent parameter in the literature in many of the problems described related to its pathologic conditions, which are often related to the repetitive loading tendons undergo during life. In other words, the study of the fatigue resistance of the tendons may provide information about the etiology of these pathologies. The elastic strain limit corresponds to the point after which micro-damage in the tendon starts. Thus, the prediction of this limit and its use in the design of fatigue loading protocols, may benefit the understanding of the onset and evolution of damage which is intimately related to the repair capacity of the cells. The variability of the elastic strain limit between different individuals makes it difficult to choose the applied load in these tests. This thesis shows a possible approach to predict the elastic strain limit based on a point-wise comparison of the sample’s stress- strain curve to a set of N number of failure curves from a database that was constructed for this purpose. The accuracy of the method proved to be statistically significantly (p <0.05) higher than other methods that were evaluated. It was also shown that it could be applied to predict the elastic strain limit of other species such as the horse’s superficial digital flexor tendon which together to the human Achilles tendon are the most injured between species. The main advantage of this method is that the higher accuracy comes along with a certainty that every prediction will be carried out, in contrast to other methods where some obstacles may render missing predictions. Finally, the smallest strain percentage up to which the sample’s stress-strain curve was used for the prediction, proved to be sufficient for obtaining similar accuracy as that with the highest strain percentage tested, with the only requirement of a moderately higher number of failure curves against to which it should be compared.

elastic limit
tendon

http://resolver.tudelft.nl/uuid:6737bce4-dab4-441e-8d10-929ca422d267

2013-11-22

Student theses

master thesis

(c) 2012 Reyes Lua, A.M.