摘要
针对多层界面相对陶瓷基复合材料(CMCs)横向开裂行为的影响进行了细观有限元模拟。在代表体单元模型中,按照界面相各亚层的实际厚度建立多层界面相几何模型,然后赋予各亚层对应的组分材料参数,建立细观有限元模型。在此基础上,分别采用扩展有限单元法(XFEM)和内聚力界面模型来模拟CMCs中的开裂裂纹和脱粘裂纹,实现复合材料横向开裂过程的模拟。对单层BN界面相和(BN/SiC/BN)、(BN/SiC/BN/SiC/BN)两种多层界面相的模拟结果进行了对比。可以看出,所研究的SiC/SiC复合材料在横向载荷作用下,首先在纤维与界面相之间产生脱粘裂纹,脱粘裂纹扩展后引起外侧基体开裂,最终引起复合材料横向失效;与单层界面相相比,多层界面相将引起不同形态的脱粘裂纹,其横向开裂应变高于单层界面相,开裂位置也存在显著差异。
The effect of multilayer interphase on the transverse cracking behavior of ceramic matrix composites(CMCs)was simulated by micromechanical finite element method.The sub-layers of interphase were created according to their real thickness within a RVE model to describe the microstructure of multilayer interphase of CMCs.The finite element method was applied to analysis the stress by defining different material properties for the interphase sub-layers.On this basis,the cracking and debonding were simulated by extended finite element method and cohesive interfacial model,respectively..After all,a simulation method for transverse cracking in the multilayer interphase was developed.The simulation results for cracking path within monolayer BN interphase,and multilayer interphase of different structure(BN/SiC/BN and BN/SiC/BN/SiC/BN)were compared.It can be seen that the interfacial debonding occurs at the interface between fiber and interphase for CMCs with multilayer interphase.Moreover,the transverse cracking strain of multilayer interphase is higher than that of monolayer interphase and the location of cracks for the two cases is very different.
作者
任嘉成
方光武
钟毅
高希光
宋迎东
REN JiaCheng;FANG GuangWu;ZHONG Yi;GAO XiGuang;SONG YingDong(School of Mechanical Engineering,Anhui University of Technology,Ma’anshan 243002,China;China Haisum Engineering Co.,Ltd.,Shanghai 200031,China;Key Laboratory of Aero-engine Thermal Environment and Structure,Ministry of Industry and Information Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)
出处
《机械强度》
CAS
CSCD
北大核心
2020年第5期1207-1213,共7页
Journal of Mechanical Strength
基金
国家科技重大专项(2017-Ⅳ-0005-0042)
国家自然科学基金项目(51675266,11972183)
安徽省高等学校自然科学研究项目(KJ2018A0057)
“航空发动机热环境与热结构”工业和信息化部重点实验室开放基金(CEPE2018006)资助。
关键词
陶瓷基复合材料
多层界面
扩展有限元法
内聚力模型
Ceramic matrix composites
Multilayer interphase
Extended finite element method
Cohesive model
