Extrusion Deformation And Pressure Control Of Winding Molding Of The Heat Insulation With Variable Curvature And Variable Thickness

The heat insulation in the combustion chamber of a solid rocket motor is a heat protection composed of ablation-resistant materials between the solid fuel and the motor case.It has good heat resistance and ablation resistance.It can reduce the temperature of the combustion chamber through continuous decomposition and ablation at high temperature,avoiding the sharp drop in strength of the motor case and even structural deformation in the harsh environment of high temperature and high pressure,ensuring that the motor can still work reliably for a long time under extreme conditions,and it plays an important role when the motor is working.At present,the heat insulation of the mandrel head is formed by compression molding,and the heat insulation of the middle section is formed by manual paving in our country.The process is complicated,the degree of automation is low,the efficiency is low,the product dimensions fluctuate greatly,and the quality stability is poor.It has become a bottleneck for the improvement of solid motor production efficiency,and seriously affects the product quality of the motor.This paper focuses on the research about the extrusion deformation of the variablecurvature heat insulation during the winding process.The main research contents include:First,a process plan for automatic winding of the heat insulation of solid rocket motor and a plan for winding molding equipment are designed,and some key technologies involved in the plan are analyzed,and the calculation method for the geometric shape of the pressure roller and the control method of winding pressure are proposed.Secondly,the mechanism of the winding extrusion deformation of the variable-curvature heat insulation is studied,the rubber extrusion deformation law of the heat insulation is revealed and clarified,and the influence of the winding pressure on the winding molding quality of the heat insulation is analyzed according to the law of the pressure distribution on the surface of the heat insulation.A mathematical model of the rubber extrusion deformation of the variablecurvature heat insulation based on the Hertz contact theory is proposed,and the relationship between the winding pressure and the deformation of the variable-thickness rubber heat insulation is established.the constant pressure mechanism and the pressure control scheme were designed.The winding control pressure is calculated using the mathematical model of rubber extrusion deformation of the heat insulation.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 principle of finite element and the simulation analysis software ABAQUS are introduced.The simulation scheme and simulation parameters were reasonably determined,and the stress distribution on the surface of the heat insulation was analyzed,and the validity of the model of the rubber extrusion deformation of the heat insulation with variable-curvature based on the Hertz contact theory was verified.