Abstract Traumatic aortic rupture (TAR) is believed to be the second most common cause of fatality associated with motor vehicle crashes(MVCs) with substantial societal and economic burdens. TAR in motor vehicle crashes is caused by a complex state of deformation progressing at high strain rates. A major step to gain insight into the possible mechanisms of TAR is to understand the mechanical behaviour of aortic tissue under loading conditions that leads to injury and failure. This study reports a total of 29 uniaxial tensile tests performed on porcine aortic tissue in the longitudinal and circumferential direction of loading. Uniaxial tensile tests were performed at targetted strain rates of 0.01/s, 70/s, 150/s and 250/s to failure. Engineering stresses reported in the study is calculated from the ratio of interially compensated measured force and initial cross sectional area whereas true strain is calculated by tracking the markers on the specimen surface using Matlabtm based digital image correlation (DIC) tool. The load – deformation behaviour of porcine aorta is found to be Non-Hookean and strain rate dependent with higher stiffness in circumferential direction compared to the longitudinal direction indicating the anisotropic behaviour of the tissue. As strain rate increased to 250/s, the failure stress ranged from 1.64 MPa to 4.84 MPa and 1.98 MPa to 7.05 MPa for longitudinal and circumferential tissues respectively. For the same range of strain rate, failure strain ranged from 26% to 37% and 24% to 42% and the elastic modulus changed from 9.42 MPa to 31 MPa and 12.33 MPa to 51 MPa for longitudinal and circumferential tissues respectively.

中文翻译：

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单轴张力下猪主动脉组织的高失败率特性

摘要 外伤性主动脉破裂 (TAR) 被认为是与具有重大社会和经济负担的机动车辆碰撞 (MVC) 相关的第二大死亡原因。机动车碰撞中的 TAR 是由在高应变率下进行的复杂变形状态引起的。深入了解 TAR 可能机制的一个重要步骤是了解主动脉组织在导致损伤和失败的负载条件下的机械行为。本研究报告了在纵向和圆周方向上对猪主动脉组织进行的总共 29 次单轴拉伸试验。以 0.01/s、70/s、150/s 和 250/s 的目标应变速率进行单轴拉伸试验，直至失效。研究中报告的工程应力是根据内部补偿测量力和初始横截面积的比率计算的，而真实应变是通过使用基于 Matlabtm 的数字图像相关 (DIC) 工具跟踪试样表面上的标记来计算的。发现猪主动脉的载荷 - 变形行为是非胡克和应变率相关的，与纵向相比，周向刚度更高，表明组织的各向异性行为。随着应变速率增加到 250/s，纵向和周向组织的破坏应力范围分别为 1.64 MPa 至 4.84 MPa 和 1.98 MPa 至 7.05 MPa。对于相同范围的应变率，破坏应变范围从 26% 到 37% 和 24% 到 42%，弹性模量从 9.42 MPa 变为 31 MPa 和 12。