应用经纬互规法建立3D机织复合材料的几何模型

采用改进的经纱脉络法表征三维机织复合材料结构, 并将单胞分解为亚胞晶阵, 提出屈曲形态码概念, 并利用编码中蕴含的信息以分段样条曲线拟合纱线中心线; 采用经纬纱互相规仿的方法, 以分段样条曲线拟合纱线截面轮廓线, 进而以解析法建立了预制件的几何模型; 将所建模型与电镜照片进行对比, 获得了较好的一致性。研究结果表明: 可用分段样条曲线描述预制件中纱线的形态; 精度相同时, 互规法建模效率远高于迭代法。

Geometric modeling of the 3D woven composite with warp and fill mutual imitation

The improved warp skeleton method was used to describe 3D woven composites architecture, and unit cell was decomposed into subcells/grids. The concept of crimp pattern code was put forward, and the yarn centerline could be fitted based on the information contained in the codes. With "mutual imitation method" of tows, cross-section contour line was fitted by sectioned spline curves. Merging centerlines and contour lines could derive yarns’ curved surfaces, which were used to create geometric model of a preform. In order to prove the effectiveness, the obtained cross-section shape is compared with SEM photo. The agreement is quite good. The results show that the sectioned spline curves can be used to describe the yarn pattern. The results also show that the efficiency of mutual imitation method is significant higher than that of iteration one under the same precision.