Lu Y T, Zhu H X, Richmond S, Middleton J
School of Engineering, Cardiff University, UK.
Comput Methods Biomech Biomed Engin. 2011 Dec;14(12):1079-88. doi: 10.1080/10255842.2010.509100. Epub 2011 Jun 24.
Skeletal muscle tissues have complex geometries. In addition, the complex fibre orientation arrangement makes it quite difficult to create an accurate finite element muscle model. There are many possible ways to specify the complex fibre orientations in a finite element model, for example defining a local element coordinate system. In this paper, an alternative method using ABAQUS, which is combination of the finite element method and the non-uniform rational B-spline solid representation, is proposed to calculate the initial fibre orientations. The initial direction of each muscle fibre is specified as the tangent direction of the NURBS curve which the fibre lies on, and the directions of the deformed fibres are calculated from the initial fibre directions, the deformation gradients and the fibre stretch ratios. Several examples are presented to demonstrate the ability of the proposed method. Results show that the proposed method is able to characterise both the muscle complex fibre orientation arrangement and its complex mechanical response.
骨骼肌组织具有复杂的几何形状。此外，复杂的纤维取向排列使得创建精确的有限元肌肉模型相当困难。在有限元模型中有许多指定复杂纤维取向的可能方法，例如定义局部单元坐标系。本文提出了一种使用ABAQUS的替代方法，该方法是有限元方法和非均匀有理B样条实体表示的结合，用于计算初始纤维取向。每条肌肉纤维的初始方向被指定为纤维所在的NURBS曲线的切线方向，并且变形纤维的方向是根据初始纤维方向、变形梯度和纤维拉伸比来计算的。给出了几个例子来证明所提方法的能力。结果表明，所提方法能够表征肌肉复杂的纤维取向排列及其复杂的力学响应。
