Study On Dynamic Mechanical Properties Of 2.5D SiO₂/SiO₂ Ceramic Matrix Composites And Its Simulation Verification

2.5D Si O₂/Si O₂ceramic matrix composites have been widely used in the manufacture of missile warheads and other special components due to their excellent wave permeability and heat resistance.In practical application scenarios,ceramic matrix composites will be affected by high speed,high temperature,high pressure and other environmental factors,so it is particularly important to explore the dynamic mechanical behavior of the material in the above environment.In this paper,2.5D Si O₂/Si O₂ceramic matrix composites were taken as the research object to study the damage mechanism of 2.5D Si O₂/Si O₂ceramic matrix composites under the condition of high strain rate dynamic impact compression.The dynamic impact mechanical properties and damage law of materials under high strain rate were revealed by experiment and simulation.The research is mainly divided into the following three aspects:(1)2.5D Si O₂/Si O₂ceramic matrix composites are prepared by sol-gel technology,which is characterized by multiple cycles of"impregnation?curing?drying?sintering"processing process to make the ceramic matrix materials more dense and stable.According to its production method and the spinning and weaving process,we further determine the 2.5D Si O₂/Si O₂ceramic matrix composites geometry and material properties,facilitate the reasonable division of cell,build 2.5D shallow curved structure of geometric model,calculation model theory to predict the content of fiber volume fraction,and compare the results with the actual measurement quantity,It is verified that the established geometric model accords with the actual situation.Then,the fiber bundle RVE model was established and the static elastic parameters of Si O₂/Si O₂ceramic matrix composites were simulated and predicted for subsequent simulation research.(2)The formation and structure of the single-cell model of 2.5D Si O₂/Si O₂ceramic matrix composites were studied,and the finite element model of Si O₂/Si O₂ceramic matrix composites was established at the mesoscopic level.On this basis,dynamic impact compression simulation was carried out to predict the dynamic mechanical properties of 2.5D Si O₂/Si O₂ceramic matrix composites.(3)Set up a platform for high strain rate dynamic compression mechanics test(SHPB test device),and complete 2.5D Si O₂/Si O₂ceramic matrix composites SHPB test scheme planning and sample size design.The stress(?)-strain(?)curves of 2.5D Si O₂/Si O₂ceramic matrix composites under different strain rates in the same direction and the same strain rate in different directions were analyzed.To dynamic SHPB test result and(2),comparing the forecasting results of dynamic impact compression model through error analysis,shows that the dynamic impact compression model effectively predict 2.5D Si O₂/Si O₂dynamic mechanical properties of ceramic matrix composites,on the basis of the finite element model,can further for other dynamic mechanical properties prediction and research materials.