Rate- and Region-Dependent Mechanical Properties of Göttingen Minipig Brain Tissue in Simple Shear and Unconfined Compression
Rate- and Region-Dependent Mechanical Properties of Göttingen Minipig Brain Tissue in Simple Shear and Unconfined Compression
复制标题
简单剪切和无侧限压缩下哥廷根小型猪脑组织的速率和区域依赖性机械特性
DOI：
10.1115/1.4056480
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Monson, Kenneth L.
中科院分区：
文献类型：
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作者：
Boiczyk, Gregory M.;Pearson, Noah;Kote, Vivek Bhaskar;Sundaramurthy, Aravind;Subramaniam, Dhananjay Radhakrishnan;Rubio, Jose E.;Unnikrishnan, Ginu;Reifman, Jaques;Monson, Kenneth L.
创伤性脑损伤，尤其是爆炸伤，是现代军事冲突中造成人员伤亡的主要原因。计算模型是理解脑外伤基本生物力学的重要工具，但它高度依赖于软组织的力学特性来产生准确的结果。据报道，脑组织的材料特性在不同的研究之间可能会有几个数量级的差异，而且还没有公布的猪脑组织在与爆炸相关的应变率下的材料参数集。在这项工作中，在准静态(QS)到300 S−1的应变率范围内，对新鲜安乐死的成年雄性Göttingen小型猪的脑干、小脑和脑组织进行了简单剪切和无侧限压缩。脑组织在剪切和压缩下都表现出显著的应变率僵硬。大脑不同区域之间的差异微乎其微。超弹性和超粘弹性本构模型都符合实验应力，考虑了单一加载模式(单向)或两种加载模式一起(双向)的数据。具有Ogden超弹性表示和单项Prony系列的单向超粘弹性模型最好地捕捉了所有区域和速率的脑组织的响应。双向模型一般能够捕捉组织在高速剪切和所有压缩模式下的响应，但不能捕捉QS剪切。我们的本构模型描述了猪脑组织的第一组材料参数，这些参数与冲击伤中所见的加载模式和速率有关。
Traumatic brain injury (TBI), particularly from explosive blasts, is a major cause of casualties in modern military conflicts. Computational models are an important tool in understanding the underlying biomechanics of TBI but are highly dependent on the mechanical properties of soft tissue to produce accurate results. Reported material properties of brain tissue can vary by several orders of magnitude between studies, and no published set of material parameters exists for porcine brain tissue at strain rates relevant to blast. In this work, brain tissue from the brainstem, cerebellum, and cerebrum of freshly euthanized adolescent male Göttingen minipigs was tested in simple shear and unconfined compression at strain rates ranging from quasi-static (QS) to 300 s−1. Brain tissue showed significant strain rate stiffening in both shear and compression. Minimal differences were seen between different regions of the brain. Both hyperelastic and hyper-viscoelastic constitutive models were fit to experimental stress, considering data from either a single loading mode (unidirectional) or two loading modes together (bidirectional). The unidirectional hyper-viscoelastic models with an Ogden hyperelastic representation and a one-term Prony series best captured the response of brain tissue in all regions and rates. The bidirectional models were generally able to capture the response of the tissue in high-rate shear and all compression modes, but not the QS shear. Our constitutive models describe the first set of material parameters for porcine brain tissue relevant to loading modes and rates seen in blast injury.