C/SiC陶瓷基复合材料界面力学性能的离散元模拟

Study on Interfaces Properties of C/SiC Ceramic Matrix Composites Using Discrete Element Method

采用离散元法(DEM),用BPM(Bonded-particle model)模型分别建立并校准SiC陶瓷基体和碳纤维离散元模型,采用位移软化接触模型表征层间和纤维/基体之间的界面元损伤双线性本构关系。通过DCB试验(Doub-le cantilever beam virtual test)和微滴脱黏试验分别对其界面强度进行收敛试验,动态地观察了塑性变形、裂纹扩展及界面脱黏过程。结果表明,位移软化接触模型可以很好地表征界面损伤过程,采用离散元法可以很好地动态模拟较复杂复合材料的损坏过程。

With the aid of BPM （Bonded-particle model）, the discrete element models of SiC ceramics matrix and carbon fiber were set up and calibrated separately by the discrete element method（DEM）. The bilinear cohesive law of interface element damage in interlayer and on matrix/fiber interface was characterized using displacement-sof- tening contact models, and then calibrated by DCB test （Double cantilever beam virtual test） and microhond test, re- spectively. Plastic deformation, crac-king growth situation and dynamic processes of interface debonding were ob- served in these simulation tests. The results show that the displacement-softening contact model could characterize in- terracial damage process nicely, and discrete element method could simulate dynamic damage process for more complex composite materials admirably.