Large strain behaviour of brain tissue in shear: some experimental data and differential constitutive model.
Large strain behaviour of brain tissue in shear: some experimental data and differential constitutive model.
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发表时间：
2001
期刊：
影响因子：
1.1
通讯作者：
Lynne E. Bilston;Zizhen Liu;Nhan Phan-Thien
中科院分区：
文献类型：
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作者：
Lynne E. Bilston;Zizhen Liu;Nhan Phan-Thien
本文报道了牛脑组织在体外大剪切应变下行为的一些实验测量，并建立了与数据一致的本构模型。据确定，脑组织不是应变时间可分离的，在较高应变下表现出较慢的松弛，并且剪切应力与剪切应变的增加不是线性的。新的本构模型是一个微分模型，包括门尼类型的“弹性”项和非线性粘弹性项。后者通过修改具有阻尼函数的上部对流多模麦克斯韦模型，允许松弛行为随应变的变化。该模型与实验剪切结果吻合良好，可用于描述其他类型的数据。
In this paper, some experimental measurements of the behaviour of bovine brain tissue under large shear strains in vitro are reported, and a constitutive model which is consistent with the data is developed. It was determined that brain tissue is not strain-time separable, showing slower relaxation at higher strains, and that the stresses in shear are not linear with increasing shear strain. The new constitutive model is a differential model, including both an "elastic" term, of the Mooney type and a nonlinear viscoelastic term. The latter allows for the change in relaxation behaviour with strain, by modifying an upper convected multimode Maxwell model with a damping function. The model shows good agreement with the experimental shear results and could be used to describe other types of data.