In this paper,the influences of bore damage on the bullet-barrel interaction process and the mechanism of how bore damage results in the end of a machine gun barrel’s service life were studied,which had seldom been p...In this paper,the influences of bore damage on the bullet-barrel interaction process and the mechanism of how bore damage results in the end of a machine gun barrel’s service life were studied,which had seldom been paid attention to in the past several decades.A novel finite element mesh generation method for the damaged barrel and a new transient coupled thermo-mechanical finite element(FE)model,which were based on the damage data obtained through barrel life tests,were developed to simulate the interior ballistics process of a coupled bullet-barrel system.Additionally,user subroutine VUAMP was developed in the FE model in order to take the bullet base pressure brought by propellant gas into account.Good consistency between the simulation results and the experimental results verified the preciseness of the proposed mesh generation method and the FE model.The simulation results show that the increase of bullet’s initial disturbance at the muzzle and the variation of its surface morphology caused by bore damage are primarily responsible for the life end of this 12.7 mm machine gun barrel.展开更多
针对当前等效全装药(Equivalent Full Charge,EFC)折算系数的国家军用标准预测值与实际测试结果差距较大的问题,基于热-化学烧蚀模型,研究不同工况下射击发数与EFC射击发数间的折算系数计算方法。射击一定发数后,假设身管内壁白层厚度...针对当前等效全装药(Equivalent Full Charge,EFC)折算系数的国家军用标准预测值与实际测试结果差距较大的问题,基于热-化学烧蚀模型,研究不同工况下射击发数与EFC射击发数间的折算系数计算方法。射击一定发数后,假设身管内壁白层厚度及成分随射击发数呈周期性变化,由质量扩散定律建立膛线起始部热-化学烧蚀量与火药燃气侵蚀性、内膛表面瞬态温度的关系。通过经典内弹道模型获得弹后空间火药燃气平均温度及内壁面强制对流换热系数,在考虑后效期高温燃气影响的基础上,建立身管内壁瞬态温度计算模型。以对内弹道过程有重要影响的射速、药量和药温为重点,计算不同射速、不同药号和不同药温下的身管内壁烧蚀量,并据此获得不同工况下的折算系数。研究发现,射速越快,装药质量越大,装药初始温度越高,单发射击造成的身管烧蚀越严重,其对应的EFC折算系数越大,其中强装药的EFC折算系数可达2.131。以某型155 mm火炮身管实弹射击数据为例,验证了新模型的合理性。展开更多
The barrel lifes of three small caliber rifles were tested by using the propellant with nanomaterial and the standard propellant respectively. The test results show that the service life increases observably due to ad...The barrel lifes of three small caliber rifles were tested by using the propellant with nanomaterial and the standard propellant respectively. The test results show that the service life increases observably due to adding nanomaterial to the propellant. Then, the influence of the nanomaterial on the tube was researched by splitting the two barrels tested and detecting their inner surfaces. It was found that the erosion of the barrel bore is reduced observably by using the propellant with nanomaterial. And it makes the volume and the size of the gun chamber change less. Therefore, the barrel life can be prolonged by adding the nanomaterial in the propellant.展开更多
A power function relation between number of rounds and barrel wear amount is created based on the test data from firing of large-caliber barrels. The function is optimized to fully fit the test data. A new concept of ...A power function relation between number of rounds and barrel wear amount is created based on the test data from firing of large-caliber barrels. The function is optimized to fully fit the test data. A new concept of diameter change rate of bore is proposed and the law of barrel wear is put forward by means of comparing the diameter change rates for large-caliber barrels with different calibers. It is shown that the law of barrel wear is successful in barrel life prediction.展开更多
基金supported by the National Natural Science Foundation of China(grant number 11802138)the China Postdoctoral Science Foundation(grant number 2018T110503)the Fundamental Research Funds for the Central Universities(grant number 30918011302)
文摘In this paper,the influences of bore damage on the bullet-barrel interaction process and the mechanism of how bore damage results in the end of a machine gun barrel’s service life were studied,which had seldom been paid attention to in the past several decades.A novel finite element mesh generation method for the damaged barrel and a new transient coupled thermo-mechanical finite element(FE)model,which were based on the damage data obtained through barrel life tests,were developed to simulate the interior ballistics process of a coupled bullet-barrel system.Additionally,user subroutine VUAMP was developed in the FE model in order to take the bullet base pressure brought by propellant gas into account.Good consistency between the simulation results and the experimental results verified the preciseness of the proposed mesh generation method and the FE model.The simulation results show that the increase of bullet’s initial disturbance at the muzzle and the variation of its surface morphology caused by bore damage are primarily responsible for the life end of this 12.7 mm machine gun barrel.
文摘针对当前等效全装药(Equivalent Full Charge,EFC)折算系数的国家军用标准预测值与实际测试结果差距较大的问题,基于热-化学烧蚀模型,研究不同工况下射击发数与EFC射击发数间的折算系数计算方法。射击一定发数后,假设身管内壁白层厚度及成分随射击发数呈周期性变化,由质量扩散定律建立膛线起始部热-化学烧蚀量与火药燃气侵蚀性、内膛表面瞬态温度的关系。通过经典内弹道模型获得弹后空间火药燃气平均温度及内壁面强制对流换热系数,在考虑后效期高温燃气影响的基础上,建立身管内壁瞬态温度计算模型。以对内弹道过程有重要影响的射速、药量和药温为重点,计算不同射速、不同药号和不同药温下的身管内壁烧蚀量,并据此获得不同工况下的折算系数。研究发现,射速越快,装药质量越大,装药初始温度越高,单发射击造成的身管烧蚀越严重,其对应的EFC折算系数越大,其中强装药的EFC折算系数可达2.131。以某型155 mm火炮身管实弹射击数据为例,验证了新模型的合理性。
文摘The barrel lifes of three small caliber rifles were tested by using the propellant with nanomaterial and the standard propellant respectively. The test results show that the service life increases observably due to adding nanomaterial to the propellant. Then, the influence of the nanomaterial on the tube was researched by splitting the two barrels tested and detecting their inner surfaces. It was found that the erosion of the barrel bore is reduced observably by using the propellant with nanomaterial. And it makes the volume and the size of the gun chamber change less. Therefore, the barrel life can be prolonged by adding the nanomaterial in the propellant.
文摘A power function relation between number of rounds and barrel wear amount is created based on the test data from firing of large-caliber barrels. The function is optimized to fully fit the test data. A new concept of diameter change rate of bore is proposed and the law of barrel wear is put forward by means of comparing the diameter change rates for large-caliber barrels with different calibers. It is shown that the law of barrel wear is successful in barrel life prediction.
