血管残余应力的一种确定方法

动脉无载荷状态下存在残余应力，分析血管壁在载荷状态下的应力分布必须计及血管壁的残余应力。本文通过检测动脉不同轴向伸长比条件下的压力—容积(p—V)数据，根据其p—V实验曲线的“S”型特征，提出了一种用反正切函数关系对试验数据点进行拟合，进而导得动脉管壁周向残余应力沿壁厚分布的方法。文章对10只正常大鼠颈动脉的分析结果表明，大鼠颈动脉周向残余应力沿血管壁厚呈单调上升趋势。残余应力在内壁处为负呈压缩状态，在外壁处为正呈拉伸状态，并且内外壁处应力绝对值大小基本相等，大约在2．5kPa左右。文章结果对进一步分析动脉管壁在载荷作用下的应力分布提供必要的信息。

A Method for Determining Vascular Residual Stress

There exists residual stress in a no-load vascular wall, which should be taken into consideration when calculating stress distribution in a loaded vascular wall. In this paper, through measuring the pressure-volume (p-V) data of artery at various axial extension ratios, and based on the p-V data's characteristic shape of "S", a method was proposed that the experimental p-V data could be fitted using arc tangent function from which the circumferential residual stress distribution along the arterial wall thickness could be derived. The analysis result on 10 normal rats indicated that the circumferential residual stress distribution in rat carotid wall is monotone increasing along the arterial wall thickness. There exists compres-sive residual stress in the inner wall region and tensile residual stress in the outer wall region, the absolute values of which are almost identical and approximately equal to 2.5kPa. The results provide necessary information for further study on stress distribution in the loaded arterial wall.