Study On The Shock Reaction Model For Impact Energy Release Behavior Of Al/PTFE

Reactive material is a kind of new energetic material which is widely used in military field such as weapon warhead.It is inert under normal temperature and pressure,but can release a lot of chemical energy under impact.The shock energy release behavior of reactive materials usually occurs under extreme conditions such as high temperature,high pressure and transient state.The reaction mechanism is complex and the chemical reaction process is difficult to be directly monitored.The process of impact energy release of reactive materials is different from the process of impact initiation of traditional high energy explosives and the existing reaction model describing the impact initiation of explosives is difficult to apply to Reactive materials.Therefore,understanding and describing the impact reaction behavior of active materials on a macro scale is one of the hot issues to be urgently solved in promoting the engineering application of active materials.The main research contents of this paper are as follows:(1)A typical reactive material Al/PTFE(mass ratio of Al to PTFE is 26.5:73.5)was studied.According to literature research and numerical simulation results,the impact energy release behavior of Al/PTFE was simplified and a phenomenological impact reaction model was proposed.The model was composed of three parts: the state equation of the unreactant,the state equation of the reaction product and the reaction rate equation.It can describe the mechanical-chemical reaction behavior of the reactive material during the impact compression process.(2)The mathematical expression description of the impact reaction model was described,and reverse impact test,thermochemical analysis and forward impact test were carried out to test the mechanical and chemical properties of the material.On the basis of the test data,the model parameters of the impact reaction model of the reactive material were obtained by numerical simulation fitting.(3)Based on the mature platform of LS-DYNA nonlinear dynamics simulation software,the impact response model was embedded into the material library of the software in the form of a custom equation of state,and the writing process of the custom equation of state was introduced in detail,and the correctness of the writing of the equation was verified.(4)The numerical simulation results of Al/PTFE reactive material in several typical application scenarios,such as the shell of armor piercing projectile and the inner core of transverse effect enhanced projectile(PELE),were demonstrated.The results show that the impact reaction model proposed in this paper can well describe the mechanical-thermal-chemical coupling behavior of Al/PTFE reactive materials in the impact compression process at a macro scale,which is of great significance to accelerate the engineering application of reactive materials in the military field such as weapon damage.