ABSTRACT

Robotic Automated Fiber Placement (R-AFP) technology was developed to manufacture composite laminates by placing carbon fiber thermoset towpregs, obtained by impregnating 12 K high-strength grade carbon fibers in an epoxy resin system. In order to avoid placement induced defects, a thermographic scanning technique was implemented for on-line quality monitoring of the R-AFP process. The thermal analysis proved to be an effective and quick approach for the real-time detection of deposition defects generated during. The R-AFP process was performed by applying a constant pressure through the compaction roller; different pressure values were investigated. The effect of the resin weight fraction and compaction pressure on the mechanical properties applied by the deposition head during R-AFP of cross-ply laminates was studied. The reduction of the tensile strength and the increase of the elastic modulus with decreasing pressure of the compaction roller was observed. Furthermore, the values of ultimate tensile strength and elastic modulus decrease as the resin content increases. Finally, the three-dimensional topography of surface fracture of tensile samples was investigated by means of the optical and scanning electron microscopy.

摘要

机器人自动纤维铺放（R-AFP）技术是通过将碳纤维热固性丝束放置在复合材料中而制成的，该纤维束是通过将12 K高强度级碳纤维浸渍在环氧树脂体系中而制成的。为了避免放置引起的缺陷，实施了热成像扫描技术以对R-AFP工艺进行在线质量监控。事实证明，热分析是一种实时检测沉积过程中产生的缺陷的有效且快速的方法。R-AFP工艺是通过压实辊施加恒定压力来完成的；研究了不同的压力值。研究了树脂重量分数和压实压力对交叉层压板R-AFP期间沉积头施加的机械性能的影响。随着压实辊的压力降低，观察到拉伸强度的降低和弹性模量的增加。此外，极限拉伸强度和弹性模量的值随着树脂含量的增加而降低。最后，通过光学和扫描电子显微镜研究了拉伸样品表面断裂的三维形貌。