Research And Numerical Simulation Of The Damage Properties Of The Ceramic On Ceramic/Metal Composites

In modern military, protection to vehicles and army is an utmost important link for raising ability of troops. Since World War One, metal became the core in the preparation of armed material. But, notonly the proportion of metal brought in ability of protection, but also lowered the maneuvering performance. As a typical example, Tiger was useless without mobility. Hence, it was a significant goal to search the balance point between protection and maneuvering. Since World War Two, destination of investigation was designed to raise maneuvering without sacrifice defense. What is more, the combat system of USA aims at lightening armor in future.Boards of ceramic/metal composite, not only have a metal better the ballistic resistance, but also have characters of lower density, higher hardness and higher strength. Since that, these have met the need of lightening armor and become the core of studying materials of armor nowadays. Although, investigation has proceeded for several decades, but the injury mechanism of composites is still insufficiently clear. At present, unlike in metals, destruction mechanism still has many problems since large amount species. In the thesis, investigation starts from structure of composites and mainly concerns features of destruction in the process of perforating. Impacts of structure on ballistic resistance performance are gotten by numerically simulating process of perforating.In the thesis, the penetration of composites targets, aiming at investigation of structure, has been simulated by LS-DYNA. The remaining velocity and the kinetic energy attenuation of bullet are obtained to evaluate the ballistic resistance performance of composites. The main conclusions are as follows:1. The primitive parameters, which include parameters of constitutive models of materials, parameters ofcontact and perforate algorithm are obtained from literals and experiments results. The penetration model is built in the software.2. Composites targets, composed of different ceramics with the same area density and total thickness are constructed. Damage of variable ceramic are analyzed to obtain the impact of thickness of ceramic on ballistic resistance ability.3. The spread of stress wave, the damage, the ballistic resistance abilities of certain ceramic/metal composites target are investigated, while keeping its area density and total thickness same, varying its thickness ratio of the front plate and the back plate.4. The investigations on micro-holes are also carried out to explore the impact on the projectile-retarded ability of composites target by varied porosity condition of ceramic.Theoretical basis for the design and optimization of the composite armor are studied by modeling, selecting the boundary conditions and calculation methods.