基于XFEM法的Ti/TiC叠层复合材料裂纹扩展有限元分析

Finite Element Analysis of Crack Propagation of Ti/TiC Laminated Composites Based on XFEM Method

基于扩展有限元法(XFEM),模拟研究了Ti/TiC叠层复合材料在一定约束和载荷作用下断裂时的裂纹扩展行为,并验证了模拟结果的准确性和有效性。研究表明,Ti/TiC叠层复合材料表现出逐层断裂的特性,裂纹呈Z字形路径扩展。裂纹在扩展过程中,扩展方向会发生偏转,在一定程度上延长其扩展路径,消耗了大量的断裂功,从而增强了材料的断裂韧度,并具有更高的安全性和稳定性。载荷达到336.7N时,复合材料在Ti层发生一次启裂,其最大主应力值为3 048.65MPa,此时复合材料并没有完全失效。当载荷值为392.5N时,复合材料在TiC层发生二次启裂,最大主应力值达到4 557.54MPa时,复合材料才开始完全失效。

The crack propagation behavior of Ti/TiC laminated composites was investigated based on the extended finite element method(XFEM).The accuracy and effectiveness of the simulated results were verified by comparing with the existing experimental ones.The results show that Ti/TiC laminated composites exhibit layer by layer fracture characteristics,and the crack propagation is advanced in form of Z shape.In the crack propagation process,the crack propagation will be deflected,which increases the path of crack propagation and absorbs more amounts of the fracture energy,therefore the fracture toughness of the material is increased remarkably,and make the material with higher safety and stability.When the load reaches 336.7 N,the first crack initiation occurs at the Ti layer,and the maximum principal stress is 3 048.65 MPa,which leads to the absence of composites failure.The second crack of the material occurs at the TiC layer when the load value reaches 392.5 N,and the maximum principal stress reaches 4 557.54 MPa,which leads to the composites failure.