具有空隙尺寸双尺度特性的纤维织物渗透虑率的预测  

PREDICATION OF PERMEABILITY IN A GLASS-FIBER MAT WITH DUAL-SCALE PORE-SIZE

作　　者：吴炎 晏石林[2] 谭华 

机构地区：[1]广东省佛山市南海第二建筑工程有限公司,佛山528200 [2]武汉理工大学理学院工程结构与力学系,武汉430070 [3]Department of Mechanical Engineering,University of Wisconsin-Milwaukee

出　　处：《固体力学学报》2008年第S1期80-84,共5页Chinese Journal of Solid Mechanics

基　　金：国家自然科学基金项目(50573060)资助

摘　　要：纤维织物的渗透率是开展复合材料液体模塑成型工艺仿真分析的重要参数,对于数值模拟的成功与否起着关键性作用。本文中,我们首先建立了能反映一种双向缝合玻璃纤维毡周期性微观结构的三维单胞有限元网格模型,然后采用自行开发的流体分析程序对单胞有限元模型进行了稳态流体分析,对计算结果采用Darcy定理进行后处理从而预测出纤维织物的渗透率。双向缝合毡是一种典型的具有缝隙双尺度的多孔介质,即纤维束内单根纤维丝的缝隙尺寸与纤维束间的大缝隙的尺寸相差几个数量级。流体在纤维束内微隙和纤维束间空隙的饱和流动分别采用Stokes方程和Brinkman方程进行描述,并采用有限元方法对控制方程进行求解。我们同时使用一维充模实验装置对该纤维毡的渗透率进行了实验测定。实验结果表明采用本文的数值方法能够对纤维预制件的渗透率进行较为准确的预测。Permeability is fundamental to an accurate simulation of mold-filling in liquid composite molding (LCM) technologies (such as RTM) that are used for manufacturing polymer composites. In this paper, unit cell representing the micro-structure of a biaxial stitched fiber mat is used by the 3D finite element based CFD simulation to estimate numerical permeability. Stokes and Brinkman equations are employed to model the saturated flow in the inter- and intra-tow regions, respectively, of the non-crimp fiber mat with a dual-scale pore structure. The experimental permeability of the mat is measured using the 1D flow experiment. A comparison of the numerical and experimental permeabilities reveals that the permeability estimated using the unit cell is close to the real value. Explanations such as nesting between the plies, tow deformation, and overlooking of stitches in the flow simulation, can be used to explain the error witnessed in the numerical permeability obtained from the unit-cell.

关 键 词：液体复合模塑成型工艺(LCM) 渗透率 单胞 Darcy定理 有限元单元法 

分 类 号：TB302[一般工业技术—材料科学与工程]