压辊材料及形状对纤维铺放压紧效果的影响

近年来纤维铺放（AFP）技术被广泛用于大型复杂飞机复合材料构件成型。为了保证纤维铺放过程的一致性，纤维铺放压辊必须在适应芯模型面的同时具有较好的压紧力分布均匀性。鉴于此，对不同弹性模量的压辊材料进行了试验分析，薄膜压力传感器及超声显微镜测试结果表明，低弹性模量的压辊材料变形较大，较好地适应了芯模表面，压力分布相对均匀且可以减少铺层的层间孔隙数量，硅橡胶压辊比聚乙烯压辊压紧力分布均匀性提高了50%~60%，铺层孔隙率降低了92.1%。针对孔隙分布主要集中在压辊两端及压紧力在压辊两端下降幅度较大的问题，采用ANSYS Workbench对压辊端部进行斜端面优化，得到最优倾斜角度为20°；测试结果表明斜端面压辊压力分布均匀性比直断面压辊提高了42.9%，铺层孔隙率下降了51.6%。

Effect of Material and Shape of Compaction Roller on the Voids and Compaction Uniformity in Fiber Placement Process

Automated fiber placement(AFP) has been used to form the large aircraft composites structure in recent years. To ensure the consistency of process in AFP, the compaction roller should be flexible to adapt to the model surface with big curvature and also press the placing prepreg uniformly. In this paper, thin film pressure sensor and ultrasonic microscope are used to measure the pressure uniformity and void distribution of compaction rollers with different elasticity modulus. Compaction roller made with high elasticity modulus material exhibited good pressure uniformity and also reduced the void content. Compared with the polythene roller, the pressure uniformity of the silastic roller is improved by 50% to 60%, and the void content is decreased by 92.1%. Based on the fact that the voids distributed mainly on both sides of the prepreg and the pressure was much smaller on both sides of the roller than that in the middle area of the roller, the shape of two sides of the compaction roller is optimized. The best dip angle of the side plane calculated by ANSYS Workbench module is 20°, the pressure uniformity is improved by 42.9%, and the void content is decreased by 51.6% further.