Schools of Aeronautics/Astronautics and Materials Engineering, Purdue University, West Lafayette, IN 47907-2045, USA.
J Mech Behav Biomed Mater. 2011 Jan;4(1):76-84. doi: 10.1016/j.jmbbm.2010.09.007. Epub 2010 Sep 25.
This study aims to experimentally determine the strain rate effects on the compressive stress-strain behavior of bovine liver tissues. Fresh liver tissues were used to make specimens for mechanical loading. Experiments at quasi-static strain rates were conducted at 0.01 and 0.1 s(-1). Intermediate-rate experiments were performed at 1, 10, and 100 s(-1). High strain rate (1000, 2000, and 3000 s(-1)) experiments were conducted using a Kolsky bar modified for soft material characterization. A hollow transmission bar with semi-conductor strain gages was used to sense the weak forces from the soft specimens. Quartz-crystal force transducers were used to monitor valid testing conditions on the tissue specimens. The experiment results show that the compressive stress-strain response of the liver tissue is non-linear and highly rate-sensitive, especially when the strain rate is in the Kolsky bar range. The tissue stiffens significantly with increasing strain rate. The responses from liver tissues along and perpendicular to the liver surface were consistent, indicating isotropic behavior.
本研究旨在通过实验确定牛肝组织在压缩应力-应变行为中的应变速率效应。使用新鲜的肝组织制作用于力学加载的标本。在 0.01 和 0.1 s(-1) 下进行准静态应变速率实验。在 1、10 和 100 s(-1) 下进行中间速率实验。使用为软材料特性而修改的 Kolsky 杆进行高应变速率（1000、2000 和 3000 s(-1)）实验。使用带有半导体应变计的空心传输杆来感知软试样的微弱力。使用石英晶体力传感器来监测组织试样上的有效测试条件。实验结果表明，肝组织的压缩应力-应变响应是非线性的，并且对速率非常敏感，尤其是当应变速率处于 Kolsky 杆范围内时。组织的刚度随应变速率的增加而显著提高。沿肝表面和垂直于肝表面的组织的响应一致，表明各向同性行为。
