Research On Mechanical Properties Of Composite Cartridge Under Ultra-high Load

Fiber-reinforced composite materials are more and more popular because of their advantages such as high specific strength and specific modulus,good fatigue resistance,and good safety performance during overload.From the initial application in the aerospace field,and subsequently in military supplies,to a wide range of applications in construction,electrical engineering,chemistry,machinery,sports and other industries and people's daily life supplies,it has a very broad development prospect.At present,most of the cartridges are made of metal products.Although the mechanical properties can meet the needs of use,the metal material production process is long and the quality is heavy.Therefore,the development of new lightweight composite material cartridges has important engineering application value.The thesis is aimed at the problems such as the unclear mechanical behavior of the composite cartridge firing state and the harsh overall service state.Combining numerical simulation and firing experiments,in-depth study of the firing state stressstrain characteristics of the cartridge and the failure limit conditions of the cartridge which provides a basis and reference for the optimal design of the composite material cartridge structure.The main work and conclusions of the paper are as follows:(1)The inner layer of the cartridge is made of aramid fiber-epoxy based composite material by winding molding,and the outer layer of the cartridge is injection-molded with glass fiber reinforced high-density polyethylene to prepare a composite cartridge sample.(2)The physical model of the stress and strain analysis of the composite material cartridge was established,and the stress of the inner and outer layers of the composite material cartridge in the firing state was analyzed.Through the stress balance differential equation and geometric equation under the axisymmetric structure,the three-dimensional stress distribution law of the cartridge was calculated.And using the failure theory of epoxy aramid fiber cloth and chopped glass fiber reinforced highdensity polyethylene,the failure analysis of the composite material cartridge was carried out.Combined with the gas pressure boundary conditions during the firing of the cartridge,the maximum blasting internal pressure that the composite cartridge can withstand is predicted to be 60.9MPa.(3)Based on the failure theory of epoxy aramid fiber cloth and chopped glass fiber reinforced high density polyethylene,combined with the gas pressure boundary conditions of the cartridge during the firing process.Using ANSYS simulation software,the deformation process,stress size and distribution law of the composite material cartridge in the firing state were numerically simulated,and the maximum burst pressure obtained was 63.7MPa.Based on the above mathematical calculations and simulation results,the firing state failure pressure of the composite cartridge is 60-70 MPa,which provides a basis for the optimization of the composite material structure and material selection.