Research On Dynamic Compression Mechanical Properties Of ZrB₂-based Ultra-high Temperature Ceramic Composites

With the rapid development and leapfrog progress of Aerospace Technology,hypersonic vehicles in the atmosphere,high-speed reentry vehicles and reusable transatmospheric vehicles have become the hotspots of research.Its high supersonic speed,long flight time and reusable service characteristics put forward higher and higher requirements for its material performance.ZrB₂-based ultra-high temperature ceramic composites have the characteristics of high melting point,high hardness,high thermal conductivity,excellent high temperature strength and oxidation resistance.Therefore,as a new generation of thermal protection materials,it has attracted wide attention and is expected to be applied to high temperature thermal structures such as flange,nose cone and engine of hypervelocity vehicle.Under the condition of high-speed service of aircraft,it is not only affected by high temperature,but also by the pressure of aerodynamic load,so it is very important to study the dynamic impact resistance of materials.In this paper,the dynamic compression properties of ZrB₂-based ultra-high temperature ceramic composites are studied by dynamic compression experiments of separated Hopkinson bar and numerical simulation by ANSYS/LS-DYNA finite element analysis software.Firstly,the compression strength and the corresponding compression strength of materials under different strain rates are studied by dynamic compression experiments of separated Hopkinson bar.Then the SHPB experiment was simulated by finite element analysis software ANSYS/LS-DYNA,and the parameters of the original JH-2 model were revised according to the experimental results,and compared with the compressive strength and stress-strain curve obtained from the experiment,the correctness of parameter selection was verified.At the same time,combining the failure process of specimens captured by high-speed camera under different strain rates and simulating the failure process of specimens in the experiment,the failure mechanism of specimens under different strain rates is analyzed,which lays a foundation for the next application of materials and the design of related structures.