Study On Internal Ballistic Characteristics Considering Dynamic Extrusion Process Of Ballistic Belt

Based on the XXX ministry’s “13th Five-Year Plan” key pre-research project,this paper studies the influence characteristics of the extrusion of a large-caliber grenade shell on the internal ballistic characteristics through experimental and numerical simulation techniques.The mathematical model of the elastic squeezing process of the elastic belt is established.Based on the model,the integrated model of the turbulent motion after the ballistic squeezing process and the end of the squeezing process is further established.The influence of different influencing factors on the overload of the projectile is analyzed.The main work and conclusions are summarized as follows:(1)Experimental study on the process of elastic band extrusionThe experimental device for the extrusion process of a certain type of armor-piercing projectile and howitzer belt was designed.The piezoelectric pressure sensor and high-speed camera were used to record the pressure change in the crucible during the extrusion process and the movement displacement of the projectile.The motion parameters of the projectile were summarized and analyzed.The law of change.The experimental results show that the pressure at the position of the slope and the pressure at the bottom of the raft are basically the same during the squeezing process.At the end of the squeezing process,the projectile bottom pressure is much greater than the squeezing pressure in the classical internal ballistic theory and has a certain velocity at the end of the projectile extrusion process.(2)Numerical simulation of the extrusion process of a large-caliber howitzerOn the basis of experimental research,a three-dimensional nonlinear calculation model of dynamic extrusion of projectiles was established,and the ABAQUS software was used to simulate the extrusion process of the elastic belt.The results show that the extrusion speed of the elastic belt is obviously different under different loading conditions.The larger the charging amount,the faster the elastic belt extrusion speed and the shorter the completion time.In the case of a small charge,negative acceleration may occur.As the amount of charge increases,the extrusion resistance at the same position of the elastic band increases with the increase of the charge amount;under the different charge conditions,the resistance of the elastic band is similar to the stroke curve,and there is a slow rise and a sudden acceleration phenomenon.During the failure of the elastic band failure,the resistance exhibits a certain oscillation;before the end of the extrusion process,the resistance has a maximum value,and the position of the value depends on the relative position of the elastic band and the twist line;The increase in the amount is gradually increasing.(3)Internal ballistic numerical simulation taking into account the dynamic squeezing process of the elastic beltThe internal ballistic model of a certain type of artillery involving the dynamic extrusion process of the elastic belt was established,and numerical simulation was carried out to investigate the effects of the elastic belt and the structure size and the amount of charge on the overload of the projectile.The results show that the internal ballistic model of the instantaneous extrusion and the internal ballistic model of the dynamic squeezing process of the elastic belt are very different in terms of the movement of the projectile,the law of the force,and the completion time of the internal ballistic process.The theory and model of extrusion have important application value in modern internal ballistic theory.Based on the above simulation,considering the different initials of the ammunition,different projectile structures,different charging conditions and the friction coefficient between the ammunition,the overload of the grenade launching process was numerically simulated to obtain the overload in the grenade.Change the law.