iMechanica - Comments for "Fractional-order nonlinear hereditariness of tendons and ligaments of the human knee"
https://imechanica.org/node/24232
Comments for "Fractional-order nonlinear hereditariness of tendons and ligaments of the human knee"enTendons and Ligaments, Nonlinear Hereditariness
https://imechanica.org/comment/30326#comment-30326
<a id="comment-30326"></a>
<p><em>In reply to <a href="https://imechanica.org/node/24232">Fractional-order nonlinear hereditariness of tendons and ligaments of the human knee</a></em></p>
<div class="field field-name-comment-body field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><span>In this paper, the authors pointed out the main features of a wide experimental campaign devoted </span><span>to investigate the mechanical behaviour of knee tendons subjected to long-standing loads. The </span><span>results of the experimental campaign show that creep and relaxation behaviour of the tendons </span><span>may be well captured by power laws in the ranges of strain (1–5%) and stress (0–16 Mpa) </span><span>considered.</span></p>
<p><span>The order of the power law proved to be different between creep and relaxation proving that </span><span>some form of nonlinearity is involved in the micromechanics of the tissue so that no linear theory </span><span>of fractional hereditariness may be used to capture the mechanics of tendons. Moreover, it has </span><span>been observed that the material parameters are significative dependent on the applied stress in </span><span>creep tests as well as on the applied strain during relaxation.</span></p>
<p><span>These features, already observed in other mechanical tests in the last 20 years, have never been </span><span>conducted in combination on human tendons, yielding one to conclude that the finding relaxation </span><span>runs faster than creep is valid also on human knee patellar and hamstring tendons.</span></p>
<p><span>Based on this observation, the paper was devoted to the introduction of an analytical model </span><span>to describe creep and relaxation showing that some closed-form expression relating creep and </span><span>relaxation parameters could be established.</span></p>
<p><span>Direct comparison among results of such expressions and the measured values showed </span><span>excellent matches with slight coefficient of variations and, in order to show that such relations </span><span>hold whatever kind of test is considered, a numerical validation has been introduced with other </span><span>than constant value of the applied strain (stress), namely linear and harmonically varying strain </span><span>(stress).</span></p>
<p><span>The obtained results showed excellent match among the initial and the recovered values of the </span><span>applied stress (strain) leading one to conclude that the proposed relations may be a benchmark </span><span>to provide clinical support to the surgeons that apply pre-stress to the tendons before surgical </span><span>replacement to reconstruct anterior cruciate ligaments functionality.</span></p>
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</ul>Sun, 24 May 2020 14:47:04 +0000Luca-Desericomment 30326 at https://imechanica.orgError | iMechanica