Placeability restricted by in-complete contact between laying roller and mould in an automated fiber placement process

Abstract

In this study, the effect of a roller’s deformability on the placeability restricted by an incomplete contact between a laying roller and mould in an automated fiber placement process was analyzed. The incomplete contact phenomenon was defined theoretically through the differential geometry, and corresponding criteria of placeability were proposed by analyzing the mechanism of interlayer bonding. A finite element model was established to simulate the pressure distribution on the contact zone. The pressure measurement of laying on a curved mould was conducted and the infrared thermographic method was utilized to detect the layup defects. The results of the theoretical analysis showed that the criteria of placeability must satisfy complete contact and pressure’s uniformity simultaneously and be implemented in the condition of laying on a cylinder mould with a fixed angle trajectory. The deformability of the roller with different layup forces relates to its material module and its geometry. The finite element model of pressure distribution was verified by an experiment, and the quantitative relationship between the uniformity of pressure and roller’s module, mould’s radius and tows’ width was acquired by this model. With the increase of module and tows’ width, the uniformity decreases; while with the increase of mould’s radius, the uniformity increases. The thermographic results showed that optimized parameters can guarantee the interlaminar bonding to avoid delamination for laying on the curved mould with a restriction of the incomplete contact.