In this paper,a novel large caliber machine gun was taken as the research object to analyze the floating technique based on the principle of fixed-point constraint and secondary counter-recoil.A rigid-flexible couplin...In this paper,a novel large caliber machine gun was taken as the research object to analyze the floating technique based on the principle of fixed-point constraint and secondary counter-recoil.A rigid-flexible coupling multi-body dynamic model of the large caliber machine gun with muzzle brake based on floating principle was established,in which the influence of soil and human body was taken into account.The dynamic simulation was conducted and then the results were compared with the corresponding experimental data The dynamic characteristics of the machine gun with or without floating technique were analyzed to indicate the influence of floating technique upon the performance of the gun.Furthermore,the rigid-flexible coupling dynamic models with five different firing angles was constructed to study the influence caused by the angles.The results indicated that the floating mechanism could reduce the recoil effectively and improve the operational performance of this novel large caliber machine gun.展开更多
Machine gun barrels differ from their rifle counterparts in terms of profile.To support high rates of sustained fire,machine gun barrels are made thicker in order to dissipate more heat and maintain their flexural rig...Machine gun barrels differ from their rifle counterparts in terms of profile.To support high rates of sustained fire,machine gun barrels are made thicker in order to dissipate more heat and maintain their flexural rigidity and thus accuracy,but on other hand they also contribute in weight addition to weapon.This investigation deals with comparison between a conventional machine gun barrel and an improved innovative design having T-fins,both having same weight and chambered in 5.56×45 NATO ammunition,to compare their structural and harmonic characteristics which were parameterized by factors such as modal spectrum,directional deformation at muzzle ends during a single shot fire and harmonic behaviour at corresponding range of exciting frequencies.The solid models of both the barrels having same weight,were created using Solidworks.The continuous input data functions were generated by MATLAB using the field tested discreet data points.The generated velocity-distance functions were converted into time dependent functions using integration algorithms to calculate transient parameters such as time steps,excitation frequency range,angle of rotation of projectile and its angular velocity.The dynamic condition simulated the varying nature of forces due to eccentricity in projectile and this data was fed to a time step study using ANSYS transient structural work bench followed by modal and harmonic analysis.The results showed a significant reduction in muzzle end deformation which thus proved that the T-finned barrel,although had same weight as that of the conventional one,but had better structural and harmonic characteristics,and hence it would inherit better firing accuracy.展开更多
Improving the firing accuracy is a final goal of structural optimization of machine guns. The main factors which affect the dispersion accuracy of machine gun are analyzed. Based on the concept of dynamic stability, a...Improving the firing accuracy is a final goal of structural optimization of machine guns. The main factors which affect the dispersion accuracy of machine gun are analyzed. Based on the concept of dynamic stability, a structural optimization model is built up, and the sensitivity of dispersion accuracy to design variables is analyzed. The optimization results of a type of machine gun show that the method is valid, feasible, and can be used as a guide to the structural optimization of other automatic weapons.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.11802138China Postdoctoral Science Foundation under Grant No.2018T110503the Fundamental Research Funds for the Central Universities under Grant No.30918011302
文摘In this paper,a novel large caliber machine gun was taken as the research object to analyze the floating technique based on the principle of fixed-point constraint and secondary counter-recoil.A rigid-flexible coupling multi-body dynamic model of the large caliber machine gun with muzzle brake based on floating principle was established,in which the influence of soil and human body was taken into account.The dynamic simulation was conducted and then the results were compared with the corresponding experimental data The dynamic characteristics of the machine gun with or without floating technique were analyzed to indicate the influence of floating technique upon the performance of the gun.Furthermore,the rigid-flexible coupling dynamic models with five different firing angles was constructed to study the influence caused by the angles.The results indicated that the floating mechanism could reduce the recoil effectively and improve the operational performance of this novel large caliber machine gun.
文摘Machine gun barrels differ from their rifle counterparts in terms of profile.To support high rates of sustained fire,machine gun barrels are made thicker in order to dissipate more heat and maintain their flexural rigidity and thus accuracy,but on other hand they also contribute in weight addition to weapon.This investigation deals with comparison between a conventional machine gun barrel and an improved innovative design having T-fins,both having same weight and chambered in 5.56×45 NATO ammunition,to compare their structural and harmonic characteristics which were parameterized by factors such as modal spectrum,directional deformation at muzzle ends during a single shot fire and harmonic behaviour at corresponding range of exciting frequencies.The solid models of both the barrels having same weight,were created using Solidworks.The continuous input data functions were generated by MATLAB using the field tested discreet data points.The generated velocity-distance functions were converted into time dependent functions using integration algorithms to calculate transient parameters such as time steps,excitation frequency range,angle of rotation of projectile and its angular velocity.The dynamic condition simulated the varying nature of forces due to eccentricity in projectile and this data was fed to a time step study using ANSYS transient structural work bench followed by modal and harmonic analysis.The results showed a significant reduction in muzzle end deformation which thus proved that the T-finned barrel,although had same weight as that of the conventional one,but had better structural and harmonic characteristics,and hence it would inherit better firing accuracy.
文摘Improving the firing accuracy is a final goal of structural optimization of machine guns. The main factors which affect the dispersion accuracy of machine gun are analyzed. Based on the concept of dynamic stability, a structural optimization model is built up, and the sensitivity of dispersion accuracy to design variables is analyzed. The optimization results of a type of machine gun show that the method is valid, feasible, and can be used as a guide to the structural optimization of other automatic weapons.
