Department of Mechanical Engineering, Faculty of Engineering, Ubon Ratchathani University, Warinchumrap, Ubon Ratchathani, Thailand.
Med Eng Phys. 2011 Nov;33(9):1056-63. doi: 10.1016/j.medengphy.2011.04.012. Epub 2011 May 31.
A simple model is presented for the description of relaxation, creep, and strain stiffening phenomena that are observed in parallel-fibered collagenous tissues such as ligaments and tendons. In the model formulation, the tissues are assumed to be composed of collagen fibers aligned along their physiological loading direction. The collagen fibers are gradually recruited under strain and are arranged in parallel with a Maxwell element which accounts for the viscoelasticity of the proteoglycan-rich matrix. Once straight, the collagen fibers are assumed to behave as linear elastic springs. Experimental data published by Hingorani et al. [1] are used to estimate the five model parameters by fitting relaxation and strain stiffening data and the predictions are evaluated by using creep data. The influence of each parameter on describing relaxation, creep, and strain stiffening is presented. The modeling results demonstrate that, by considering the fibers' recruitment and assuming that the matrix is linear viscoelastic, a conceptually simple model can describe relaxation, creep, and strain stiffening phenomena in ligaments and tendons.
本文提出了一个简单的模型，用于描述平行纤维胶原组织（如韧带和肌腱）中观察到的松弛、蠕变和应变硬化现象。在模型公式中，假设组织由沿生理加载方向排列的胶原纤维组成。胶原纤维在应变下逐渐被募集，并与一个 Maxwell 元件平行排列，该元件描述了富含蛋白聚糖的基质的粘弹性。一旦变直，胶原纤维就被假设为线性弹性弹簧。Hingorani 等人发表的实验数据[1]用于通过拟合松弛和应变硬化数据来估计五个模型参数，并通过使用蠕变数据来评估预测。展示了每个参数对描述松弛、蠕变和应变硬化的影响。建模结果表明，通过考虑纤维的募集并假设基质是线性粘弹性，可以用一个概念简单的模型来描述韧带和肌腱中的松弛、蠕变和应变硬化现象。
