AUTOMATED CONTROL OF FIBER TENSION IN THE IMPREGNATION PATH DURING FILAMENT WINDING OF COMPOSITE SHELLS

Abstract

This paper presents the results of theoretical and experimental research on the process of forming composite shells by filament winding, focusing on the problem of stabilizing fiber tension during passage through the resin impregnation path. Maintaining constant fiber tension is a key factor in composite manufacturing since its fluctuation leads to irregular layer placement, internal stresses, delaminations, and deterioration of the final product’s mechanical properties. Particular attention is paid to the impregnation stage, where fiber tension varies due to changes in the viscosity of a hot-curing epoxy resin during continuous operation. A mathematical model of the roller system in the impregnation path was developed based on the Euler–Eytelwein equation, which describes the dependence of fiber tension on the wrap angle and friction coefficient of each roller. The concept of an effective friction coefficient was introduced to account for the influence of temperature, partial polymerization over time, and the degree of fiber wetting. The proposed model allows for quantitative evaluation of tension variation in real time and enables optimization of process parameters for stable operation. To ensure constant fiber tension, a hardware–software automatic control system was developed using an Arduino Uno microcontroller. The system includes an HX711 load cell amplifier for real-time tension measurement, an MG996R servo motor for adjusting the movable roller’s angle, and a PID controller that compensates for disturbances caused by resin viscosity fluctuations and winding speed changes. The developed control algorithm maintains the fiber tension within ±5% of the target value, even when resin viscosity increases by 30–40% during operation. Experimental validation confirmed the accuracy of the mathematical model and the efficiency of the automated control strategy. The proposed system can be applied both in laboratory studies of filament winding and in industrial installations to ensure stable manufacturing of composite shells, including casings of solid-propellant rocket motors and other high-performance composite structures.