The Design And Simulation Study Of The Principle Scheme Of The Simulation Test Device Of The Outer Ballistic Environment Of The Fuze

In order to provide foundation for fuze design,test and performance verification,a 155 mm howitzer projectile and its fuze are used as the background of application,the fuze exterior ballistics environment simulation test device is proposed and relevant simulation studies are conducted.The theory of projectile rotational movement is used to provide design basis for the fuze exterior ballistics environment simulation test device.Computational fluid dynamics simulation is conducted to provide aerodynamic parameter for six-degree-of-freedom equations for rigid trajectory of projectile exterior ballistics.Six-degree-of-freedom equations for rigid trajectory of projectile exterior ballistics is solved numerically to obtain the motion of a projectile on its exterior ballistics,which provides input parameters for the fuze exterior ballistics environment simulation test device.The modal vibration of the device is analyzed through finite element method to ensure that the device does not resonate during operation.ADAMS is used to simulate the motion of the test device,the influence of dynamic unbalance on internal parts of the fuze and the strength of the device are also analyzed.Through further research on the theory of projectile rotational movement,the law of variation of attack angle of projectile on its exterior ballistics is decomposed into movement on two coordinate axes in a coordinate plane.Because the motion on the two axes is reciprocating,the variation of attack angle on the exterior ballistics can be simulated by using machanism to implement these two motions and then synthesizing these motions.In order to obtain the motion of a 155 mm howitzer projectile and its fuze on the exterior ballistics,six-degree-of-freedom equations for rigid trajectory of projectile exterior ballistics is studied.In order to obtain aerodynamic parameters of the exterior ballistics trajectory of the projectile for six-degree-of-freedom equations,firstly,the credibility of the simulation method is verified,the conclusion is that the deviation between aerodynamic parameters obtained by simulation method and those obtained by experiment is within acceptable range.Then the flow field of the projectile is simulated to obtain aerodynamic parameters of the projectile.When solving six-degree-of-freedom equations for rigid trajectory of projectile exterior ballistics,the unbalance of projectile motion is considered,and the calculated result is compared with the generally accepted credible empirical formula and the motion equation of projectile centroid to verify the calculated result.The three-dimensional model of the exterior ballistics environment simulation test device is established,the rotational motion of the motor is decomposed into reciprocating motion on two coordinate axes in the same coordinate plane by using universal joint drive mechanism,crank slider mechanism and rack and pinion mechanism.The device can directly simulate the six-degree-of-freedom equations for rigid trajectory of projectile exterior ballistics to obtain the law of variation of attack angle.At the same time,the modal vibration of the whole device is analyzed,the first six modal vibration frequencies and the maximum deformation of the device are obtained.The motion frequency of the device must avoid the natural vibration frequency of the device itself,otherwise resonance may occur and the device may be damaged.ADAMS is used to analyze the motion of the fuze exterior ballistics environment simulation test device.The results show that the motion of centroid of the fuze in the device is in good agreement with theoretical analysis results,thus the motion of the projectile and its fuze on exterior ballistics can be simulated.The device implements simulation of motion of the projectile when the fuze axis and the rotating axis of the projectile are not aligned with each other,which proves that the device scheme can test the safety and reliability of the projectile and the fuze in this situation.The movement data of the device is used to analyze the mechanical strength of the device,and the conclusion shows that the parts and components of the device are qualified in strength and will not be damaged by fatigue.