我们表明，猪脑物质可以准确地建模为一个非常柔软的橡胶状材料使用Mooney-Rivlin应变能函数，高达60%的应变。该结果来自于在准静态应变率下对小矩形新鲜样品（$2.5$ cm $^3$和$1.1$ cm $^3$）进行的简单剪切实验。它们揭示了线性剪切应力-剪切应变关系（$R^2> 0.97 $），这是Mooney-Rivlin材料在大应变下的特征。我们发现猪脑物质对剪切力的抵抗力比硅凝胶低约30倍。我们还通过实验验证了大脑物质表现出非线性弹性的正坡印亭效应，并且在数值上，应力和应变场在简单剪切中在整个样品的厚度上保持基本均匀。
英文摘要：
We show that porcine brain matter can be modelled accurately as a very soft rubber-like material using the Mooney-Rivlin strain energy function, up to strains as high as 60\%. This result followed from simple shear experiments performed on small rectangular fresh samples ($2.5$ cm$^3$ and $1.1$ cm$^3$) at quasi-static strain rates. They revealed a linear shear stress--shear strain relationship ($R^2> 0.97 $), characteristic of Mooney-Rivlin materials at large strains. We found that porcine brain matter is about 30 times less resistant to shear forces than a silicone gel. We also verified experimentally that brain matter exhibits the positive Poynting effect of nonlinear elasticity, and numerically that the stress and strain fields remain mostly homogeneous throughout the thickness of the samples in simple shear.
Influence of twist direction and large deformation on soft material torsional contact
Hefei University of Technology（合肥工业大学）；Politecnico di BARI（巴里理工大学）；Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高等研究院）；Anhui Province Key Laboratory of Digital Design and Manufacturing（安徽省数字设计与制造重点实验室）
Generalized invariants meet constitutive neural networks: A novel framework for hyperelastic materials
Institute of Applied Mechanics, Friedrich-Alexander-Universität Erlangen-Nürnberg（应用力学研究所，埃朗根-纽伦堡弗里德里希-亚历山大大学）；Mathematical Institute, University of Oxford（数学研究所，牛津大学）；Department of Mechanical Engineering, Stanford University（机械工程系，斯坦福大学）
