Effect of Multi-Scale Porosity in Local Permeability Modelling of Non-Crimp Fabrics
Effect of Multi-Scale Porosity in Local Permeability Modelling of Non-Crimp Fabrics
复制标题
DOI：
10.1007/s11242-007-9161-0
复制
发表时间：
2008-05
影响因子：
2.7
通讯作者：
M. Nordlund;T. Lundström
中科院分区：
文献类型：
--
作者：
M. Nordlund;T. Lundström
研究了纤维增强材料的多尺度孔隙率对局部渗透率的影响，以确定简化渗透率模型以进行更有效的渗透率计算的可能性。开发了双轴无卷曲织物的晶胞模型，并用于研究在模拟局部渗透率时是否可以排除多孔束。控制计算的数值准确性，以保证结果和从中得出的结论的质量。研究发现，具有高纤维密度的纤维束可以从渗透率模型中排除，而具有低纤维体积分数的纤维束需要被包括在内。开发了一种模拟多尺度增强材料局部渗透性的新方法，并针对束中的低纤维密度进行了验证。在该方法中，通过修改代表束间区域的单尺度模型的边界条件来包含纤维束内部流动的影响。因此，多尺度增强材料的局部渗透率可以通过具有所有纤维束孔隙率的简化流体域的模型来计算，而不是通过由整个多尺度几何形状组成的模型来计算。
The influence of multi-scale porosity of fibre reinforcements on local permeability is investigated, in order to determine the possibility of simplifying permeability models for more efficient permeability calculations. Unit cell models of a biaxial Non-Crimp Fabric are developed and used to investigate, whether or not the porous bundles can be excluded, when modelling the local permeability. Numerical accuracy of calculations is controlled to guarantee the quality of the results and the conclusions drawn from them. It is found that fibre bundles with high fibre density can be excluded from permeability models, while bundles with low fibre volume fractions need to be included. A new method to model the local permeability of multi-scale reinforcements is developed and verified for low fibre density in the bundles. In this method, the effects of the flow inside the fibre bundles are included through modifications of the boundary conditions of a single-scale model representing the interbundle regions. The local permeability of multi-scale reinforcements can, therefore, be calculated by models with simplified fluid domains for all fibre bundle porosities, instead of being calculated by models consisting of the entire multi-scale geometry.