Department of Engineering and Architecture, University of Parma, Parco Area delle Scienze 181/A, 43124 Parma, Italy.
Department of Engineering and Architecture, University of Parma, Parco Area delle Scienze 181/A, 43124 Parma, Italy.
J Mech Behav Biomed Mater. 2021 Jul;119:104530. doi: 10.1016/j.jmbbm.2021.104530. Epub 2021 Apr 17.
Brain tissue is a heterogeneous material, constituted by a soft matrix filled with cerebrospinal fluid. The interactions between, and the complexity of each of these components are responsible for the non-linear rate-dependent behaviour that characterises what is one of the most complex tissue in nature. Here, we investigate the influence of the cutting rate on the fracture properties of brain, through wire cutting experiments. We also present a computational model for the rate-dependent behaviour of fracture propagation in soft materials, which comprises the effects of fluid interaction through a poro-hyperelastic formulation. The method is developed in the framework of finite strain continuum mechanics, implemented in a commercial finite element code, and applied to the case of an edge-crack remotely loaded by a controlled displacement. Experimental and numerical results both show a toughening effect with increasing rates, which is linked to the energy dissipated by the fluid-solid interactions in the region surrounding the crack tip.
脑组织是一种不均匀的材料，由充满脑脊液的软基质构成。这些成分之间的相互作用及其复杂性导致了其非线性率相关行为，这是自然界中最复杂的组织之一的特征。在这里，我们通过线切割实验研究了切割速率对脑断裂特性的影响。我们还提出了一种用于软材料断裂传播率相关行为的计算模型，该模型通过孔隙超弹性公式包含了流体相互作用的影响。该方法是在有限应变连续体力学的框架内开发的，在商业有限元代码中实现，并应用于由受控位移远程加载的边缘裂纹的情况。实验和数值结果均表明，随着速率的增加，出现了增韧效果，这与裂纹尖端周围区域的流固相互作用耗散的能量有关。
