Explosive Shock Initiation Phenomenological Reaction Rate Model Study

Phenomenological reaction rate model of shock initiation in heterogeneous explosives is a significant research direction in detonation physics. According to the train of thought which comprise experiment research, theoretical analysis, finding regular, putting forward initial reaction rate model, finding theoretical support, improving reaction rate model, verifying feasibility of reaction rate model, putting forward conclusion, research has been completed. A phenomenological reaction rate model base on mechanism of crack nucleation was put forward and numerical simulation was used to verify feasibility of reaction rate model.Establish viewpoint:Shock initiation experiments of JOB-9003 were conducted using artillery and LANL magnetic gauges made of AL, and particle velocity of reaction was measured. Using CIM and improved CIM, flow distribution of shock initiation of JOB-9003 was analysed and initial reaction rate model was put forward. DEM numerical simulation using PFC3D was made to research mesoscale response of inhomogeneous explosives under shock, and regular of mechanism of crack nucleation was found. Mechanism of crack nucleation can affect shock initiation was assumed and a reaction rate model based on phenomenological analysis and mechanism of crack nucleation was put forward.Argument:redevelopment DYNA2D used the new reaction rate model, and made numerical simulation of shock initiation of JOB-9003, PBX-9501, PBX-9502 and double shock initiation of PBX-9501 to research if the new reaction rate model has wide application and stability. Numerical simulations of shock initiation of PBX-9404, PBX-9501, EDC37 were made using the new reaction rate model and Lee-Tarver Reactive Burn Model to research which model is more effective.Conclusion:The new reaction rate model has good feasibility and validity for the shock initiation and detonation for reaction zone of JOB-9003, PBX-9501 and PBX-9502, and the results of numerical simulation can match particle velocity of experiments of JOB-9003, PBX-9501 very well while can match particle velocity of experiments of PBX-9502 well. The new reaction rate model can numerical simulate double shock initiation of PBX-9501 stably. The new reaction rate model has better effect in numerical simulation of particle velocity of shock wave front, arrival time of shock wave, peak particle velocity and particle velocity curve shape in reaction zone compared with the Lee-Tarver Reactive Burn Model which is the most widely used.Prospect:Some of the research in this paper is still in the qualitative stage. At the same time, the new reaction rate model should be further improved to have a better effect in numerical simulation of PBX-9502 and similar explosives. At the same time, the numerical simulation results using the new reaction rate model in double shock initiation experiments are still in the stage of qualitative discussion while there is no experimental research. Further work is mainly focused on the nucleation mechanism of the crack and its relationship with Initiation, in order to obtain a more perfect reaction rate model.