基于大鼠尾部悬吊实验的三维有限元模型建立与分析

Establishment and analysis of three-dimensional finite element model based on tail-suspended rat experiment

针对微重力环境模拟中广泛采用的大鼠尾部悬吊实验,采用三维有限元方法,研究尾部关节在有限元建模中的必要性。应用CT扫描与计算机软件手段,采用Abaqus有限元软件建立模拟失重的大鼠尾部悬吊三维有限元模型,并在此三维有限元模型基础上计算了尾部悬吊大鼠尾部、腰椎、骨盆、股骨等部位在考虑关节软骨与未考虑关节软骨两种情况下的应力分布和位移变化情况。结果显示,考虑软骨与不考虑软骨的两种情况下,尾部悬吊大鼠各部位应力与位移分布数值差异较大,这将影响到模型的计算准确性。故在建立尾部悬吊大鼠三维有限元模型时,关节软骨的考虑是很有必要的。同时,盆骨应力分布的不对称性,提示尾吊大鼠的左右平衡水平会对大鼠应力分布造成影响。

By using three-dimensional finite element analysis method, the necessity of tail joints in the establishment of finite model specifically for the widely used tail-suspended rat experiments in weightlessness simulation was explored. A weightlessness tail-suspended three-dimensional finite element rat model was established using CT scan and Abaqus software, and the computation and analysis were conducted using the same model. The stress distribution and displacement in tail, lumbar spine, pelvis and femur of a tail-suspended rat both with and without cartilage were simulated and calculated. The results showed that stress distribution and displacement of tail-suspended rat were quite different between rats with cartilage and without cartilage, which affected the calculation precision of the model. Accordingly the consideration of articular cartilage in establishing the tail-suspended three-dimension finite element rat model is quite necessary. In addition, the asymmetry of pelvis stress distribution of tail-suspended rat suggests that the degree of balance of tail-suspended rat will affect the stress distribution in rats.