AUTOMATED FIBER PLACEMENT: RELATION OF COMPRESSION SHEAR AND TENSILE TESTS OF TAPE LAYING AND WINDING

The automated fiber placement process with in situ consolidation (AFPisc) performs the laydown and consolidation of fiber reinforced tapes using thermoplastic matrices in one step. To find processing windows at adequate placement rates to avoid subsequent consolidation processes is challenging, as correlations of test results from reference processes are not always given in this multiparameter experimental environment. In this work, wedge-peel-based processing conditions of carbon fiber reinforced polyamide 6 (CF/PA6) are further specified. Compression shear tests are investigated to characterize the layer bonding strength and correlated to basic tensile linear elastic properties. With additional split disk tests of rings, the substantial differences of tape laying and winding are further analyzed. The results reveal the importance of the parameter processing temperature, whereas the placement rate is of minor significance. A correlation of the matrix dominated compression shear and transverse tensile tests was found in contrast to those in fiber direction. A general increase of stiffnesses was found using the split disk tests. The transverse tensile stiffnesses in the range of 60 % to a pressed reference were increased to the range of 80 % using the split disk tests. Based on these experiments, a placement rate of 18 m/min is suggested.