| Carbon fiber wound type ? composite pressure vessel has great application prospects in new energy vehicles and aerospace fields due to its advantages of light weight,corrosion resistance and fatigue.Type ? composite pressure vessels lined with engineering plastics have no relevant standards in China and have not formed large-scale industrialization.Therefore,research work in this area is relatively rare.Here,the following five aspects of carbon fiber wound type ? composite pressure vessel are studied:(1)For the problem that the lining rigidity of the ? type composite pressure vessel is lower than that of the metal lining,the stability of the lining used in the winding experiment was analyzed before the winding experiment.The calculation method of critical instability load of cylindrical liner is derived by Mises formula.Then,based on eigenvalue method and Riks arc length method,the characteristic buckling and post-buckling behavior of the liner are analyzed,and the critical instability load of the liner is obtained.The characteristic buckling and post-buckling behavior of the inner liner without thickness is studied.(2)According to the balance relationship between the micro-element method and the force,the mechanical model of the back pressure generated by the spirally wound and circumferentially wound fibers on the inner liner is given,and the analytical calculation method of the back pressure of the inner liner under the thin-walled winding structure is determined.Refer to the post-buckling instability analysis results to determine the optimum winding tension value.(3)The winding angle and the winding layer design are completed based on the grid theory by the NOL ring test results and load conditions.It is determined that the geodesic winding is used,the winding angle of the barrel section is 12.47°,the number of spiral winding layers is 5,and the number of circumferential layers is 15.Based on the Runge-Kutta method,the MATLAB software is used to solve the winding linear equation,and according to the uniform and stable winding rules,the optimal winding pattern is determined to be 5 tangent winding;the five-point linear line is traversed by MATLAB software.The simulation studies the distribution of fibers on the inner lining.The cubic spline function method was used to predict the thickness of the wound layer at the head.Considering the thickness accumulation at the head and the fiber overlap on the whole pressure vessel,it was determined that the final winding experiment was performed by winding two yarns.(4)Based on the designed winding parameters,the ? model pressure vessel was accurately geometrically modeled by the finite element software ABAQUS to study its mechanical response under working pressure and burst pressure.The results show that under the working pressure,the maximum stress value of the fiber layer is much lower than the fracture strength of the fiber layer,and the composite pressure vessel is in a safe state.The maximum strain criterion is used to predict the burst pressure of the pressure vessel,and the structure is subjected to low pressure blasting under the pressure of 57 MPa.The area is the area of the parallel circle with a radius of 51.74 mm-67.65 mm.Aiming at this problem,the head cap reinforcement method combined with the reaming method is proposed.The structural blasting pressure is increased by 17.5%,and the fiber fails at the boundary between the barrel and the head.(5)Using the four-axis CNC filament winding machine,using T800HB-12000-50 B carbon fiber and EW-6F epoxy resin,using two yarn,five-cut point,geodesic and other winding parameters to complete the plastic liner carbon fiber full-wound type ? Molding of composite pressure vessels.It verifies the reliability of the structural design.The work done in this paper can provide design ideas and technical routes for carbon fiber wound ? composite pressure vessels,laying a theoretical and experimental basis for the development of ? composite pressure vessels. |
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