Reliability Analysis And Research Of Firearm Firing-ignition System

In firearms,the components that complete the function of firing primer to ignite propellant are collectively called firing-ignition system.The working process of the firearm firing and ignition system is:when the bullets into a gun,pull the trigger,hammer spring push hammer blow needle,needle hit the primer,the firing charge in the primer is impacted,and the fire platform is relatively squeezed into the firing agent,The firing drug is squeezed to form a hot spot,and the growth of the hot spot causes the surrounding drug to burn and produce a flame,The flame passes through the fire hole of the shell casing,igniting the propellant in the shell casing,and the high-pressure gas produced by the combustion of the propellant launches the projectile.In the actual use,it is affected by many factors such as design and manufacturing,assembly technology and combat environment,no ignition,early ignition and primer breakdown often occur in firearms,which can affect the automatic firing process,damage the key parts of firearms,and even cause casualties.Therefore,it is of great significance to study the performance reliability of firearms-ignition system.Based on gun firing-ignition system as the research object,using theoretical analysis,numerical simulation and experiment validate the method of combining model based on fault tree analysis,random reliability theory,the stress-strength interference theory and related theory,established a firing-typical fault of ignition system fault tree,determine the cause,fire-ignition faults are the main factors,The finite element method was used to analyze the performance and sensitivity of the firearms-firing ignition system.On this basis,the reliability analysis model of the firearms-firing ignition system was established,and the reliability analysis test of the firearms-firing ignition system was carried out to verify the reliability analysis model.It provides data support and theoretical basis for further study on optimization design and reliability control method of firearm firing ignition system.The main research contents of this paper are as follows:（1）Based on the research on the fault mechanism of firearm firing-ignition system,the typical firing and ignition fault trees such as"Non-ignition","Non-cocking","Cocking weakness","Early ignition"and"Primer breakdown"were established and qualitative analysis was carried out.The results show that the main factors leading to the firing-ignition fault of firearms are the load of firing needle,the shape and size of firing needle,the protruding quantity of firing needle,Primer loading depth,Thickness of primer shell and wall,The shape and size of the fire station head,Degree of deviation,Material properties change under high and low temperature environment,etc.（2）Through the finite element analysis software and combined with the improved drop hammer firing device,the analysis model of firearm firing and ignition performance was established,and the model was parameterized.The sensitivity analysis of the main factors leading to the ignition failure was carried out by using the optimal Latin hypercube experimental design method.The results show that the drop hammer height（LH）,primer loading depth（ZH）and ambient temperature（T）have negative effects on the pressure starting time QT of the objective function,and LH>T>ZH;The thickness of primer shell（DH）,deviation degree（PHD）,radius of fire station head（RH）and radius of hitting needle（RJ）have a positive effect on the pressure starting time QT of the objective function,and RH>RJ>DH>PHD.（3）Based on the research of the basic theory of reliability analysis,response surface model（RMS）,radial basis functions,elliptical basis functions and Kriging model were used to establish four proxy models,and choose the highest fitting precision（R~2 value biggest）of the response surface model as the proxy model of firearms firing-ignition system.The stress-strength interference model,Monte Carlo method and proxy model were used to construct the reliability analysis model of firearm firing and ignition,and the model was implemented in Isight software.（4）Gun firing-ignition reliability analysis model are obtained by the above（3）,carried out at room temperature,high temperature,low temperature environment,different height of the reliability of the simulation analysis,at the same time using the gun firing-ignition simulation test device for the corresponding temperature and under high reliability analysis of the test,the reliability analysis model is verified,the model error is less than20%,It shows that the model is accurate and meets the engineering requirements.