Theoretical Investigation On Ceramic By Peridynamic Theory Based On The Johnson-holmquist Constitutive Model

With modern warfare turning from battlefield,trench warfare to local war,steering fighting,military personnel and vehicles are facing growing threat on the battlefield,therefore,the armor protection technology has become an important part of the development of military equipment in various countries.The ceramic has the characteristics of high hardness,high strength,high toughness and low density etc.As material for armor,it has incomparable advantages over traditional materials,and became the hotspot of material researching in the world.With the improvement of computer performance,numerical simulation has become more and more popular.However,due to the impact problem of ceramic armor relates to the fracture and failure,using numerical simulation method like finite difference method and finite element method,which based on the continuum mechanics theory is very difficult.Because of the contradiction between the continuity of the fracture problem with the noncontinuous of the theory.As a new non-local theory,the peridynamics theory has advantage over continuous mechanical theory in dealing with fracture and failure problem.Therefore,in this paper,the mechanical properties of ceramic materials are studied by using numerical simulation method with peridynamics theory combine the JH-2 model.The main research contents and results of this paper are follows:1.In order to realize the constitutive relationship based on continuum mechanics,the strain gradient and the first Piola-Kirchhoff stress were described by deformation state and force state based on non-ordinary state-based peridynamics theory.Finally,obtained the peridynamics ceramic model which suitable for the high-speed impact problem.2.By using FORTRAN language designed and programed peridynamics simulation program.A numerical example was presented by using the same model which Johnson and Holmquist had used,and the results were compared to verify the correctness of the model.3.In order to verify the reliability and feasibility of the model,simulation of the impact at edge of the ceramic plate and the glass plate crash were carried out with the same model parameters of Strassburger’s and Bouzid’s experiment by using the program.