碳纤维增强碳化硅mini复合材料超高温塑性本构关系实验和理论研究OA

Advanced ceramic matrix composites have excellent properties,such as resistance to ultra-high tem-peratures and corrosion,as well as high specific strength and stiffness.They are important candidates for ther-mal protection materials and structures of new-generation hypersonic vehicles.However,ceramic matrix com-posites have complex microstructures and various damage mechanisms,which make the study of their constitu-tive relations challenging.Minicomposites are the critical link in the multi-scale study of ceramic matrix com-posites.The study on their mechanical behaviors is important to the development and evaluation of security and reliability of advanced ceramic matrix composites.The tensile properties of C/PyC/SiC minicomposites were measured at 2 200℃in inert atmospheres for the first time based on the indirect induction heating technology.The plastic deformation behaviors of ceramic matrix composites under ultra-high-temperature extreme environ-ments were revealed.The random cracking of matrix was characterized by a 3-parameter Weibull model.The stress distributions of fiber and matrix were calculated based on the slip-lag model.The effects of ultra-high-temperature nonlinear deformation of fiber bundles and residual thermal stresses in the composites were char-acterized.An ultra-high-temperature plastic mesoscale constitutive model was established for C/PyC/SiC mini-composites and verified.The study is useful for the development of mechanics for ceramic matrix composites and provides experimental and theoretical supports for the reliability evaluation and life prediction of ceramic matrix composites on the hypersonic vehicles.