【摘要】 准确预测预成型体渗透率对复合材料液态成型工艺过程仿真有重要意义,铺覆过程中织物发生的剪切变形对局部渗透率有很大影响。本工作考虑纱线的可渗透性,对织物单胞内的树脂流动建立了统一的流动控制方程,同时建立了逼真的正交单胞几何模型,基于Adams-Bashforth差分格式和Chorin投影法构造了数值求解树脂流动控制方程的高分辨率TVD格式,利用达西定律预测了单胞的渗透率,算例表明该算法预测值与实验值有较好的吻合,验证了算法的准确性。在正交单胞渗透率求解的基础上,采用贴体坐标法完成了单胞剪切变形后流动控制方程从物理域到计算域的转换,进而实现了剪切单胞渗透率的数值预测,考察了单胞主渗透率比与剪切角的关系,通过与文献中数据对比证明了该剪切单胞渗透率预测算法的合理性。更多还原

【Abstract】 The accurate prediction of preform permeability has important implications for mould-filling simulation of liquid composite molding.The shear deformation of textile during draping process has a great influence on the local permeability of preform.Considering the permeability of yarn,the unified mathematical model for the resin flow in unit-cell was established,and the geometry model close to the real orthogonal unit-cell structure was built.Based on the Adams-Bashforth difference scheme and Chorin projection method,a numerical method with high resolution TVD schemes for solving the governing equations of resin flow was developed,and then the permeability was predicted using Darcy’s law.The prediction results agreed well with experimental results,the validity of the algorithm was proved.On the basis of the permeability prediction of orthogonal unit-cell,the body-fitted coordinates system was employed and the governing equations were converted from physical domain to computational domain to simulate the resin flow in the sheared unit-cell and predict its permeability,then the relationship between the ratio of principal permeability and shear angle was studied.The results indicate that the method provided by this paper is convenient and effective.更多还原