Université de Lyon, F-69622 Lyon, France.
J Biomech. 2010 Mar 22;43(5):927-32. doi: 10.1016/j.jbiomech.2009.11.002. Epub 2009 Dec 1.
Biological soft tissues exhibit a strongly nonlinear viscoelastic behaviour. Among parenchymous tissues, kidney and liver remain less studied than brain, and a first goal of this study is to report additional material properties of kidney and liver tissues in oscillatory shear and constant shear rate tests. Results show that the liver tissue is more compliant but more strain hardening than kidney. A wealth of multi-parameter mathematical models has been proposed for describing the mechanical behaviour of soft tissues. A second purpose of this work is to develop a new constitutive law capable of predicting our experimental data in the both linear and nonlinear viscoelastic regime with as few parameters as possible. We propose a nonlinear strain-hardening fractional derivative model in which six parameters allow fitting the viscoelastic behaviour of kidney and liver tissues for strains ranging from 0.01 to 1 and strain rates from 0.0151 s(-1) to 0.7s(-1).
生物软组织表现出强烈的非线性黏弹性行为。在实质组织中，肾脏和肝脏的研究比大脑少，本研究的首要目标是报告振荡剪切和恒剪切速率试验中肾脏和肝脏组织的附加材料特性。结果表明，肝脏组织的顺应性更高，但应变硬化程度高于肾脏。已经提出了大量的多参数数学模型来描述软组织的力学行为。本工作的第二个目的是开发一种新的本构律，该本构律可以用尽可能少的参数来预测我们在线性和非线性黏弹性范围内的实验数据。我们提出了一种非线性应变硬化分数导数模型，其中六个参数可以拟合肾脏和肝脏组织的黏弹性行为，应变范围为 0.01 到 1，应变速率范围为 0.0151 s(-1) 到 0.7 s(-1)。
