典型小口径自动步枪热散形成原因分析与结果预估

Cause Analysis and Result Prediction of Thermal Dispersion for Typical Small Caliber Rifles

热散现象是小口径自动步枪在连续射击后出现的射弹散布异常现象,对热枪状态命中率和作战效能有重要影响,形成机理尚不完全清楚。通过冷热枪对比试验发现,热枪状态下枪管向铜材料弹头壳传热,弹头壳温度升高、材料变软,弹与枪相互作用,使弹头出膛速度偏角和弹轴摆角大幅度增大,这是热散的主要原因。基于试验获得的热散机理,提出一种典型小口径自动步枪热散分析计算方法。该方法采用分段建模和参数传递方法,通过建立热枪状态枪管温度场和应力场分析模型、弹-枪相互作用热力耦合计算模型和随机外弹道及射弹散布计算模型,实现了热枪状态射击密集度的定量分析计算。计算结果与试验结果基本一致,为小口径自动步枪热散问题定量分析提供了有效预估策略。

Thermal dispersion is an abnormal phenomenon of bullet dispersion after continuous firing of a small-caliber automatic rifle.It has an important influence on the shooting accuracy and combat effectiveness of the hot gun,but the formation mechanism of thermal disperison is not completely clear.Through the comparison experiment of hot and cold guns,it is found that,in the hot gun state,the barrel transfers heat to the copper bullet jacket,then the temperature of the jacket increases to soften the material,and the interaction between the bullet and the barrel greatly increases the deflection angle of bullet velocity and the swing angle of bullet axis,which is the main reason of thermal dispersion.A thermal dispersion analysis and calculation strategy for a typical small-caliber automatic rifle is proposed based on the thermal dispersion mechanism obtained from the experiment.Hot gun state barrel temperature field and stress field analysis model,bullet-barrel interaction thermos-mechanical coupling calculation model and random exterior ballistic and bullet dispersion calculation model are established by using the method of segmental modeling and parameter transfer,which realizes the quantitative analysis and calculation of the firing dispersion in hot gun state.The calculated results are basically consistent with the experimental results.The research in this paper provides an effective calculation method for the quantitative analysis of thermal dispersion problem of small-caliber automatic rifles.