Material characterization of the pig kidney in relation with the biomechanical analysis of renal trauma
Material characterization of the pig kidney in relation with the biomechanical analysis of renal trauma
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DOI：
10.1016/s0021-9290(98)00180-8
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发表时间：
1999-04-01
影响因子：
2.4
通讯作者：
Niederer, P
中科院分区：
文献类型：
--
作者：
Farshad, M;Barbezat, M;Niederer, P
本研究的目的是调查的材料特性的新鲜猪肾和参数表征其弹性和非弹性材料行为。材料调查包括密度测量，单轴以及三维压缩试验，拉伸试验，和剪切试验的样品提取新鲜的猪肾。为了进行比较，还对许多软合成材料进行了密度测量。在不同的加载速率下对皮质组织的径向和切向样本进行压缩测试。对置于压缩室中的皮质组织进行三轴压缩测试。通过将圆柱体冲压到皮质切片中进行剪切测试。对外囊进行拉伸试验。为了表征材料行为，使用基于双参数Blatz模型的非线性理论模拟。为了表征猪肾皮质的时间依赖性行为，采用四参数线性粘弹性模型。通过实验和理论研究，得出以下结论：（1）猪肾皮质在压缩状态下的一般行为表现出软组织的典型非线性特征;应力应变图由非常低应力水平（约30%）下非常平坦的部分组成相对变形，随后是急剧上升的硬化，导致样品的径向破裂，其最大标称破裂应变约为50%. (2)对皮质组织径向和切向试样的单轴压缩试验表明，随着加载速率的增加，断裂应力增加，但相应的断裂应变减小。(3)在恒定载荷下对皮质骨进行的长期单轴压缩试验表明，皮质骨的瞬时变形和蠕变响应最终趋于渐近线。(4)通过Blatz模型模拟单轴压缩下皮质组织的非线性材料行为，给出了皮质在径向和切向方向上的两对材料参数。进而将假设的四参数线性粘弹性模型与实验数据进行拟合，得到粘弹性材料参数。(C)1999 Elsevier Science Ltd.保留所有权利。
The objective of this study was an investigation of the material properties of the fresh pig kidney and parametric characterization of its elastic and inelastic material behavior. The material investigation included density measurements, uniaxial as well as three-dimensional compression tests, tensile tests, and shear tests on the samples extracted from the fresh pig kidney. For comparison, density measurements on a number of soft synthetic materials were also performed. Compression tests on the radial and the tangential specimens from the cortex tissue were performed at various loading rates. 'Three-axial compression tests were performed on the cortex tissues placed in a compression chamber. Shear tests were performed by punching a cylinder into a slice of the cortex. Tensile tests were carried out on the outer capsule. For characterization of the material behavior, a non-linear theoretical simulation based on a two parameter Blatz model was used. For characterization of the time-dependent behavior of the pig kidney cortex, a four-parameter linear viscoelastic model was employed. From the present experimental and theoretical studies, a number of conclusions were derived:(1) The general behavior of the pig kidney cortex samples under compression showed the general non-linear features typical of the soft tissues; the stress strain diagram was composed of a very flat part at very low stress level to about 30% relative deformation which was followed by a steeply rising stiffening leading to the radial rupture of samples marked by a maximum nominal rupture strain of about 50%.(2) The uniaxial compression tests on the radial and the tangential samples from the cortex tissue showed an increase of the rupture stress with the increase in the loading rate, but a decrease in the related rupture strain.(3) The long-term uniaxial compression tests on the cortex specimens under sustained constant load showed an instantaneous deformation followed by a creep response which eventually approached an asymptote.(4) Simulation of the non-linear material behavior of the cortex tissue under uniaxial compression by the Blatz model gave two pairs of material parameters for the cortex in the radial and the tangential directions. Furthermore, fitting of the assumed four parameter linear viscoelastic model with the experimental data resulted in the viscoelastic material parameters. (C) 1999 Elsevier Science Ltd. All rights reserved.