RESIDUAL-STRESS AND STRAIN IN AORTIC SEGMENTS
RESIDUAL-STRESS AND STRAIN IN AORTIC SEGMENTS
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DOI：
10.1016/0021-9290(87)90290-9
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发表时间：
1987-01-01
影响因子：
2.4
通讯作者：
VOSSOUGHI, J
中科院分区：
文献类型：
--
作者：
VAISHNAV, RN;VOSSOUGHI, J
在血管节段应力和应变的研究中，通常假设没有轴向力且没有血管内和血管外压力的节段所呈现的无牵引构型是无应力的。为了研究这一假设的有效性程度，从 3 个牛主动脉和 6 个猪主动脉上切下 286 个椭圆形环并拍照。在这些环上进行放射状切割，将其打开成马蹄形，并拍照。从照片中测量环内膜和外膜水平处的平滑边界长度及其切开配置，并计算环形配置中相对于开放配置的残留污点。结果发现：（1）所有九个主动脉在未切割结构中的平均最大残余内膜工程应变为-0.082，而牛主动脉和猪主动脉单独的平均最大残余内膜工程应变分别为-0.096和-0.077； (2) 所有主动脉的平均最大残余外膜应变为 0.085，牛主动脉和猪主动脉的平均最大残余外膜应变分别为 0.102 和 0.078； (3)估计平均有益压应力为-0.188×。内膜水平可提供105 Pa（对应-0.082应变水平），以抵消体内血管内压力造成的拉应力； (4)估计平均初始拉应力为0.195×。 105 Pa（对应于 0.085 的应变水平）存在于外膜水平，这增加了由于血管内压力而产生的体外拉伸应力。虽然这些应力水平与动脉壁的体内应力相比并不大，但详细的应力分析必须考虑这些初始应力。
In the study of stresses and strains in vascular segments, it is generally assumed that the traction-free configuration assumed by a segment where there is no axial force and there are no intravascular and extravascular pressures is stress-free. To investigate the degree of validity of this assumption, 286 oval shaped rings were excised from three bovine and six porcine aortas and photographed. Radial cuts were made in these rings which opened up into horseshoe shapes and were also photographed. Smoothed boundary lengths at intimal and adventitial levels in the rings and their cut open configurations were measured from the photographs and the residual stains in the annular configuration relative to the open configuration were computed. It was found that: (1) the average maximum residual intimal engineering strain in the uncut configuration was -0.082 for all nine aortas and -0.096 and -0.077 for the bovine and porcine aortas alone, respectively; (2) the average maximum residual adventitial strain was 0.085 for all aortas, and 0.102 and 0.078 for the bovine and porcine aortas alone, respectively; (3) an estimated average beneficial compressive stress of -0.188 .times. 105 Pa (corresponding to a strain level of -0.082) is available at the intimal level to counteract the in vivo tensile stress due to the intravascular pressure; (4) an estimated average initial tensile stress of 0.195 .times. 105 Pa (corresponding to a strain level of 0.085) exists at the adventitial level which adds to the in vitro tensile stress due to the intravascular pressure. Although these stress levels are not large in comparison with the in vivo stress in the arterial wall, a detailed stress analysis must take into account these initial stresses.