Study On The Mechanism And Application Of Explosive Diode

Engineering blasting is one of the important technologies in economic construction,which is widely used in many national economic fields,such as transportation,water conservancy,coal,metallurgy and so on.However,bad environments especially high temperature cause early blasting great loss.At home and abroad,researchers have put forward many solutions to high temperature environment,such as extinguishing fire to cool zone,explosives and blasting equipments resisting high temperature.But fewer people study how to reduce the loss the early burst loss when the early explosion occurs.In this paper,an explosive logic network for industrial use was designed,which was based on the military explosive logic network.And the core of the network was the explosive diode designed.In this paper,we design and optimiz the explosive diode which was able to transmitting detonation signals from the main detonating network to blasting holes and stop reversing detonation signals from blasting holes to the main detonating network.In this way,the explosive diode can protect main detonating network from being detonation when early blasting occurr in some blasting holes.The importance of the explosion diode is using the transmitting fire element(delay element)as the stopping detonation element.The delay element is lead with delay composition.Detonation signals from the network fire the delay composition in the lead block and then ignite the firing charge,which makes the internal cylinder bottom cut and generates high velocity flyer plate.The flyer plate shocks and ignites the booster charge.After that,Detonation signals pass the second detonating fuse to output.When premature detonation happens,furthermore,reversing detonating signals from the holes pass the second detonating fuse,booster charge,and firing charge and at last are stopped by the lead with delay composition.Because the delay composition in the lead is not detonating but just combusting.Attenuated by the lead,the shock wave doesn’t ignite the detonating fuse.The intelligent functions rely on the lead with delay composition which is a transmitting fire component and used to stop shock wave.Besides we also optimize the parameter of explosive diode by the symmetric charge structure.Reliability of transmitting forward detonation is decided by firing charge and there is a critical mass of firing charge.In these experiments percentages of successfully transmitting detonation is 100%when the mass is more than 20mg.On the other hand,reliability of stopping reversing detonation is decided by lead with delay composition and there is a minimum length of lead.In these experiments percentages of successfully stopping detonation is 100%when the length is more than 4.30mm.Based on the basic principle of detonation wave and shock initiation,the mechanism of explosive diode is studied and the one-dimensional transmitting forward detonation model and stopping reversing detonation model are put forward.The transmitting forward detonation is divided into 3 stages to show quantitative relationships between mass of firing charge and velocity of flyer.By defining reliability coefficients about transmitting detonation,quantitative relationships is given between mass of firing charge and reliabilty of transmitting detonation.Stopping reversing detonation is divided into 3 stages.Quantitative relationships between length of lead and reliabilty of stopping detonation are given by defining reliability coefficients about stopping detonation.Results of calculations are consistent with the experiments.Through the establishment of the above two mathematical models,the mechanism analysis of the explosive diode is given,which proves that the explosion of the explosive diode is stable and reliable.Taking account of the one-dimensional theory,we simulate the transmitting forward detonation and stopping reversing detonation using LS-DYNA software and the ignition and growth model.Especially the length of delay element in stopping detonation and mass of friring charge in transmitting detonation are discussed in detail to supplement the theory of the fourth chapter and show details of detonation process of development in the booster charge and the detonating cord.The reliability of transmitting forward detonation is determined by the mass of firing charge.The larger the charge is,the faster the projectile velocity is,and the larger the initial impact pressure is,the easier the forward detonation is.The results show that the firing charge is lower than 10mg,and the forward detonation is inevitable,which is more than 20mg,and the critical pressure is reached in the final surface.The length of the delay body determines the reliability of the stopping reversing detonation,the longer the length,the greater the degree of shock wave attenuation,the smaller the impact pressure generated in the detonating cord,the more likely the success of the reverse detonation.The results show that the length of the delay body is lower than 4mm,and the reverse explosion is bound to fail,which is higher than 5mm.The flyer velocity is tested.Experiments and simulation are consistent at low weight of fring charge,however experiment is lower than theoretical values at high because the theory does not take into account the flyer damage and side effects of detonation gas overflow.