Numerical Study On The Squeezing Process Of The Cartridge Belt After The Gun Bore Is Worn Out Based On Thermal And Mechanical Coupling

In this paper,with the theory of non-linear finite element dynamics utilized,ABAQUS/Explicit finite element solver and its subroutines are used as basic tools.Based on the thermo-mechanical coupling effect,several aspects of work have been done on the numerical study of the band engraving process of a large caliber gun eroded:(1)The script modeling method of rifled barrel and the generation method of 3-D finite element model of self-tightening barrel are presented.The former makes full use of the versatility of barrel structure and outputs text information through Python scripting language programming,then directly generates its isolated grid model.And the initial residual stress in the model is loaded by using the Sigini subroutine of the initial stress field.Finally,the finite element model of the self-tightening barrel is obtained.Subsequent research and application prove that the above two methods have high model quality and modeling efficiency.(2)Based on the explicit dynamics theory of nonlinear finite element method,the dynamic variation law of rotating band engraving process and the evolution model of launching stress field of self-tightening barrel are studied.Considering the heat of inelastic work conversion and the change of thermos-dynamic properties of materials,Modification of projectile bottom load conditions and dynamic friction coefficient are made by Using multiple subprograms.Non-uniform distribution of combined Load in the Space behind the projectile are achieved,Based on the numerical simulation results,the deformation process,thermodynamic response,variation of engraving characteristics and the distribution of launching stress field in the tightened tube during the process are discussed in detail.(3)To investigate the influence of different bore wear of the barrel on the engraving process,Firstly,the wear state of the barrel is described reasonably,and a script modeling method is used to establish the wear barrel model.The Abaqus/Explicit and its subroutines were used to establish the thermo-mechanical coupling model which is developed to achieve analysis and comparison about the various characters of engraving process.The simulation results show that with the increasing wear degree,the squeezed time is shortened,the velocity of projectile,pressure behind the projectile and engraving resistance are all affected to varying degrees during the period.In addition,corresponding to the reduction of relative combustible mass,various energy indicators have also changed.