基于身管应变的小口径火炮弹丸速度测试方法

Method for projectile velocity testing of small caliber guns based on barrel strain

针对传统火炮弹丸速度测试方法中存在难以获取整条速度曲线、易受环境影响、体积庞大、成本较高、操作复杂等问题,提出了一种基于身管应变的小口径火炮弹丸速度测试方法。基于30 mm口径火炮设计了应变测试仪,实现身管外壁应变测试。根据厚壁圆筒理论计算得出火炮膛压曲线,通过弹底压力解算模型得出弹底压力曲线,与弹载存储测试方法得到的弹底压力曲线进行对比。结合弹丸运动方程得出弹丸速度曲线,采用四阶龙格库塔算法建立弹丸速度仿真模型,将应变测试、弹载存储测试得到的弹丸速度曲线与仿真曲线进行对比。结果表明:应变测试、弹载存储测试与仿真弹丸速度曲线趋势基本吻合,最大速度误差分别为1.1%和0.5%,验证了应变测试方法的可行性,为小口径火炮弹丸测速开辟了新途径。

In response to the difficulties in obtaining the entire velocity curve,susceptibility to environmental influences,bulky size,high cost,and complex operation with traditional methods of projectile velocity testing for guns,a method based on barrel strain for measuring the projectile velocity within small caliber guns was proposed.A strain tester was designed for a 30 mm caliber gun to conduct strain tests on the outer wall of the barrel.The chamber pressure curve was calculated based on the thick-walled cylinder theory.The projectile bottom pressure curve was obtained through a projectile bottom pressure solving model,which was compared with the curve obtained from projectile bottom pressure storage testing method.Combining the equations of projectile motion,the projectile velocity curve was determined.The fourth-order Runge-Kutta algorithm was used to establish a projectile velocity simulation model.The projectile velocity curves obtained from strain test and projectile bottom pressure storage testing were compared with the simulated curves.The results show that the trends of the velocity curves obtained from strain test,projectile bottom pressure storage testing,and simulation are largely consistent,with maximum velocity errors of 1.1%and 0.5%,respectively.The feasibility of the strain test method is verified,which opens up a new way for projectile velocity testing of small caliber guns.