Research And Simulation Of Rubber Extrusion Deformation Of Variable Curvature And Variable Thickness Heat Insulation

The heat insulation in the solid rocket engine shell is a layer of heat insulation and ablative material between the engine composite shell and the solid propellant,which is an indispensable and important part of the solid engine.Its important role is to continuously decompose and ablate itself under the high-temperature and high-pressure gas environment of the engine,and take away most of the heat to protect the normal operation of the engine casing under high-temperature and high-pressure gas.At present,the domestic thermal heat insulation molding mainly adopts the manual patch method,which has low efficiency,high labor intensity and poor quality stability,and the automatic insulation winding equipment and winding process of the thermal heat insulation are still in the initial stage,with low winding efficiency and poor molding quality.under the high-temperature and high-pressure gas environment of the engine,and take away most of the heat to protect the normal operation of the engine casing under high-temperature and high-pressure gas.The analysis of rubber extrusion deformation of variable curvature and variable thickness heat insulation is the theoretical basis to ensure the automatic winding control of high-quality heat insulation.This paper analyzes the process of automatic winding forming of heat insulation and the extrusion deformation of rubber with variable curvature and thickness during the winding process and simulates the extrusion deformation process.The specific research contents are as follows:First,proposed a solid rocket motor heat insulation automatic winding forming process plan and automatic winding equipment design plan,The key process parameters in the process of automatic heat insulation winding forming were analyzed respectively,and the corresponding process control methods were proposed.At the same time,the paper also proposes a shape design method for winding roller and a method for calculating the width of rubber tape.Second,the rubber extrusion deformation law of variable curvature and variable thickness heat insulation is studied,and three cases of Hertz contact theory are introduced;Analyzing the squeezing deformation law of the winding forming rubber of the insulation layer,establishing the geometric model of the surface of the rubber heat insulation and the shape of the winding roller,and analyzing the geometric characteristics of the curved surface of the contact area;The rubber extrusion deformation law of variable curvature and variable thickness heat insulation was studied,and a mathematical model of rubber extrusion deformation of variable curvature and variable thickness heat insulation based on Hertz contact theory was proposed.Analyzing and calculating the pressure distribution in the deformation area,the maximum pressure and minimum pressure on the contact surface,and the corresponding position and deformation information,and calculate the pressure of the winding roller through the calculus method.Third,finite element simulation was conducted on the rubber extrusion deformation of the surface with variable curvature and variable thickness during the winding process,and the correctness of the mathematical model of the rubber extrusion deformation of the surface with variable curvature and thickness was verified;The finite element simulation method is used to compare and analyze the stress distribution on the contact surface of the cylindrical pressure roller and the elliptical rotary concave pressure contact surface which proved that the use of elliptical rotary concave pressure roller can effectively solve the problem of "warpage".The research results of this paper provide theoretical support for the quality control and trajectory planning of the automatic winding of the rubber surface of the variable curvature and variable thickness heat insulation.