Study On Reaction Rate Dynamic Constitutive Of PBX

The explosive PBX(Plastic bonded explosive) is a special kind of heterogeneous explosives, due to its easy machining and detonation is powerful and widely used in military weapon of all countries. As PBX explosive ordnance penetrator and other bomb internal charge its work will be a strong shock wave action, during processing or transportation will impact load, and so on. In conventional weapons, it is hoped that the shock waves were of the smaller can to increase the blasting damage, and in the processing and transporting or burrow weapons we hope it can absorb a certain amount of impact load and not exploded, so the impact on the condensation of PBX explosive detonation properties research is of great significance. Reaction rate of PBX condensed explosives constitutive model can well reflect the detonation properties of this special materials and can be used directly in the numerical simulation technology of PBX explosive detonation essential material model of the process, therefore, in this paper, the reaction rate of PBX condensed explosives dynamic constitutive as the core content of research. This article main research content is as follows:Firstly, this paper firstly introduces the basic theory of PBX condensed explosives dynamic constitutive model, including the unreacted explosive and the reaction products of equation of state, single temperature model mix rules and common reaction rate constitutive model, etc., for the theoretical analysis.Secondly, under the cooperation of teacher team and the seniors independent design load the Lagrange experiment device, and successfully completed the Lagrange experiment, measurement of the explosive shock initiation process at different positions of pull stress time history curve. Another group in the experimental loading device and trigger probe design made some original achievements.Thirdly, this paper based on the traditional path line method, the MATLAB program is made by replacing the integral with the differential.The experiment measured stress time history curve is used as input, we obtained mass flow field of detonation velocity, specific volume and internal energy curve. The single temperature model and mixed law introduced the concept of reaction degree and the reaction degree and initiates the relationship between the flow field physical quantity, by solving equations, the flow field of detonation reaction time history curve. Using reaction degree obtained rate curve, thus the reaction rate equation of the calibration parameters. This paper obtained the PBX trinomial ignition and growth reaction rate equation parameters of condensed explosives.Finally, numerical simulation on nonlinear finite element analysis software LS-DYNA is adopted to simulate the Lagrange experiment by using the parameters of PBX explosive percussion constitutive model. Numerical simulation result for Lagrange location of the stress time history curve is consistent with the experiment, verified the correctness of the trinomial ignition and growth equation of calibration parameter in this paper.