| The insensitive munition and fuze initiation enhancement technology was studied with insensitive munition technology.Based on the desensitization process of a fuze,the initiation enhancement technology of detonator output power,the initiation enhancement technology of flyer impact,the initiation enhancement technology of cumulative effect initiation and the detonator safety of insensitive fuze were studied through theoretical analysis,numerical simulation and experimental verification.In order to enhance initiation power of the sensitive explosive element in the insensitive fuze,the influence of the type of high explosive,shell material and the ratio of diameter to height of high explosive on the initiating power was studied by ANSYS/LS-DYNA according to the detonators' own structure.At the same time,the law of detonator structure initiation enhancement was obtained.The results show that the detonator has a strong initiating power when the type of high explosive is HMX.The initiation power from strong to weak resulting from detonator shell materials is the mild steel,titanium alloy,aluminum alloy and tungsten alloy.When the ratio of diameter to height of high explosive is between 0.81 and 0.87,the pressure at the center of the witness plate surface is the largest.The increased output power detonator detonating insensitive explosive lead was also tested.In order to solve the problem of insufficient initiation power of single-stage flyer detonator,the influence of the flyer material,air gap,two-stage charge ratio and detonator outer diameter on two-stage flyer initiation enhancement technology was studied by ANSYS/LS-DYNA,and the characteristics of two-stage flyer initiation enhancement technology were obtained.The results show that insensitive explosive lead can be detonated by the two-stage flyer detonator,which may be applied in insensitive fuze.The mild steel,titanium alloy,aluminum alloy and tungsten alloy used as flyer material can improve the initiation power in turn.With the increase of air gap,the initiation power of two-stage flyer detonator increases first and then decreases.When the air gap is 0.4 mm,the initiating power of two-stage flyer detonator is the strongest.Compared with single-stage flyer detonator structure,the simulation shows that resulting flyer speed is increased by 12.4%.With the decrease of two-stage charge ratio,the initiation power of two-stage flyer detonator increases first and then decreases.When the charge ratio is 1:1.5,the initiating power of two-stage flyer detonator is the strongest.Compared with single-stage flyer detonator structure,the simulation shows that resulting flyer speed is increased by 13.1%.When the height of the detonator remains unchanged,with the increase of the detonator outer diameter,the initiation enhancement power of the two-stage flyer detonator is gradually improved,but the trend of improvement is weakened.In order to provide a solution to the problem of insufficient initiation power of explosive elements,numerical simulation of the initiation enhancement technology of cumulative effect initiation was conducted by AUTODYN-2D,and the influence of concave structure,shell material and double bottom shell material combination on the initiation power of cumulative detonator was obtained.The results show that the hemispherical cumulative structure of detonator can enhance the initiation power,and with the increase of the diameter of the spherical dimple,the initiation power first increases and then decreases.The cone cumulative structure often leads to the phenomenon named "perforation without explosion".When the bottom shell material of the detonator is oxygen free copper,the pressure at the center of the witness plate surface is the largest.Meanwhile,the influence of the sidewall material is little.When pure aluminum-oxygen free copper bottom shell material combination is used,the pressure at the center of the witness plate surface is the largest,which is about 3.6 times of the pressure when using flat bottom detonator.Taking advantage of cumulative effect,the initiation power of the insensitive munition and fuze can be enhanced.With the increase of the shell thickness,the initiation power of cumulative effect decreases for the insensitive booster which has larger size.In order to verify the detonator safety of insensitive fuze after the initiation enhancement technology was used,the influence of accidental fires of detonator on the fuze was studied by AUTODYN based on smooth particle method,and the characteristic of the detonator safety of insensitive fuze after the initiation enhancement technology used was obtained.In view of the detonator safety of insensitive fuze in cook-off environment,the software ABAQUS is used to simulate the initiation power of sensitive explosive elements of the fuze in cook-off environment,and the energy change of detonator in cook-off environment was obtained.The results show that when the insensitive fuze used the increased power detonator,two-stage flyer detonator and the cumulative detonator respectively,the deformation of aluminum alloy fuze body was respectively only about 0.35 mm,0.55 mm and 0.05 mm and there were no dangerous fragments after the detonator exploded.Insensitive lead and booster explosives did not caused detonation reaction.Only a small pit was formed on the surface of baffle plate facing the detonator.The cumulative detonator can pass the detonator safety real situation performance test.In the cook-off test,it is not recommended to remove the detonator of insensitive fuze in fast cook-off test and it is allowed to remove the detonator of insensitive fuze in slow cook-off test.When the detonator is charged with PETN,RDX and HMX respectively,it always reacts firstly in explosive elements of the fuze.However,the ignition position and the explosion time are different from case to case. |
PDF Full Text Request