Numerical Simulation Research Of In-Situ Modeling Process For Composite Shell

Due to the advantages of high strength, high specific intensity and excellent erosion-resistance, fiber winding composite has a wide application in the fields of aerospace, energy transposition and pressure vessel. There have been many composite molding processes. Composite molding process directly determines composite molding quality. So developing high-efficiency molding process is the key to improve composite molding quality. Traditional winding-before-curing composite modeling method has low efficiency. However, in this paper, a new molding process called the in-situ molding process is researched, which can realize composite winding and curing at the same time with the method of heating the internal metal mandrel with steam. The in-situ molding process can not only save molding time and cost, but also improve quality and efficiency.In this paper the principle of the in-situ molding process is introduced. Three mathematical models including heat conduction model, cure kinetics model and strain model of the in-situ modeling process are built and initial and boundary conditions are given. The finite element method is used to realize numerical simulation of the process. Differential equations are solved by Newton-Raphson method. The validity and feasibility of the algorithm is verified. Using ANSYS and APDL, the numerical simulation program of the in-situ modeling process is developed to research the distribution and the variation of temperature, curing degree and strain, and the influences of heating rate, winding speed and film coefficient on the distribution of temperature, curing degree and strain are analyzed.The in-situ modeling process researched in this paper has been applied to the modeling of composite shell. The practical application shows that the performance of composite shell produced by the in-situ modeling process is superior to that of traditional composite modeling processes. The in-situ modeling process can realize the modeling of composite shell with low cost and high quality and efficiency. The numerical simulation of the in-situ modeling process for the cylinder shell shows that in the premise of guaranteeing curing efficiency, heating rate should be reduced and winding rate and film coefficient should be increased to improve molding quality. So the choose of the process parameters should comprehensively consider the influences of the parameters on molding efficiency and molding quality. The research supplies the new idea for the modeling of fiber winding shell with the high efficiency and quality and low cost and provides theoretical basis and analysis method for the design and optimization of the in-situ modeling process.