### Mathematical modeling of winding square carboplastic tubes

S.O. Borzov, Ukrainian State University of Chemical Technology
2019 Computer Modeling: Analysis, Control, Optimization
The results of modeling thin-walled carbon fiber tubes of square section are presented. The task of the study is to determine and account for deviations during winding and rejection of such products. Traditionally, carbon fiber winding tubes are used for dimensionally stable structures, and circular tubes are used, which are easily wound, but have significant bending during bending. To eliminate this problem, it is proposed to use square carbon tubes. Such tubes have an advantage in gluing,
more » ... e they include flat surfaces. Bending also decreases. To eliminate this problem, it is proposed to use square carbon tubes. Such tubes have an advantage in gluing, since they include flat surfaces. Bending also decreases. However, square tubes require a new approach when winding a carbon prepreg onto a square core. It is shown in the work that the main factor that leads to a spread in wall thicknesses is the alternation of straight sections and sections on the radii of rounding of a square mandrel. This cyclicity manifests itself with each revolution of the mandrel and leads to a significant increase in the pressing pressure at the corners of the square mandrel and the absence of such pressure in the straight sections of the square mandrel. There is no way to avoid this phenomenon on existing equipment. Therefore, a different approach was proposed. It consists in the fact that each manufactured element before entering the assembly phase is subjected to statistical analysis in order to determine the real moment of resistance to bending W. This analysis includes 4 steps. At the first stage, all four faces of each square tube are marked. At the second stage, the actual thickness of each wall is determined. At the third stage, the real moment of bending resistance is calculated for each of the four positions of the tube relative to the main axis of rotation. At the fourth stage, a map of the location of the tube inside the finished structure is created. This article provides the actual thickness of the carbon fiber tubes in the amount of 20 pieces. It is shown that such a method of taking into account thickness deviations will make it possible to find a reserve for reducing the deflection of the finished structure.