An analytical model for pressure distribution in automated fiber placement on irregular surfaces and its application in aeronautical manufacturing

Abstract

Automated fiber placement (AFP) is a key technology in the fabrication of composite aeronautical components, but the layup defects associated with uneven and insufficient contact pressure limit its application on irregular surfaces. Existing methods for pressure optimization in AFP are mostly based on extensive compaction experiments, which lacks theoretical basis and is not applicable to complex surfaces. In this paper, an analytical model of pressure distribution in AFP is proposed, which is suitable for any irregular surfaces. The influence of mechanical properties of contact materials and the mold curvatures on the calculation of contact pressure is taken into consideration. The Hertz theory is also extended to the three-dimensional contact area to suit the practical needs. Furthermore, an algorithm for pressure calculation along any layup path is proposed to rapid construct the pressure field. Then three sets of experiments are carried out on two aeronautical molds to validate the proposed model. The results show that the model can accurately calculate the contact pressure distribution in AFP, and compared with the previous model, the comprehensive prediction accuracy of the peak pressure is improved by 27.25 %. Combined with the layup path information, this model can be used to analyze the mechanical mechanism of layup defects, which provides a theoretical basis for the optimization of AFP parameters based on pressure distribution.