基于三维微观结构的SiC/AZ91D复合材料单轴拉伸过程中裂纹萌生扩展机制  

Crack Initiation and Propagation Mechanism of SiC/AZ91D Composites During Uniaxial Tensile Process Based on Three-dimensional Microstructure

作　　者：李怡然 尧军平[1] 梁超群 肖鹏 陈国鑫 李步炜 LI Yiran;YAO Junping;LIANG Chaoqun;XIAO Peng;CHEN Guoxin;LI Buwei(School of Aeronautical Manufacture Engineering,Nanchang Hangkong University,Nanchang 330000)

机构地区：[1]南昌航空大学航空制造工程学院,南昌330000

出　　处：《机械工程学报》2024年第16期160-170,共11页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(52065046,51661024)。

摘　　要：为避免基于线弹性力学对裂纹问题模拟时,需要在试件中预制裂纹且在裂纹尖端存在奇异性的弊端,提出在颗粒界面引入内聚力单元来模拟研究SiC/AZ91D镁基复合材料在单轴拉伸情况下裂纹萌生扩展机制,提供一种解决裂纹扩展问题的新手段。结果表明:SiC颗粒的引入能够有效阻挡裂纹的萌生扩展,颗粒体积分数增加或者颗粒尺寸的增加均会加速复合材料的裂纹扩展过程,降低其伸长率,与试验情况吻合较好;SiC/AZ91D镁基复合材料拉伸过程中裂纹萌生扩展机制是颗粒与基体交界处萌生裂纹,微裂纹相互连接形成主裂纹,并绕开颗粒进行扩展致使材料断裂。To avoid the drawbacks of pre cracking in specimens and singularity at the crack tip when simulating crack problems based on linear elasticity,it is proposed introducing cohesive elements at the particle interface to simulate and study the crack initiation and propagation mechanism of SiC/AZ91D magnesium based composites under uniaxial tension,providing a new approach to solving crack propagation problems.The results show that the introduction of SiC particles can effectively block the initiation and propagation of cracks.An increase in particle volume fraction or particle size will accelerate the crack propagation process of composite materials,reduce their elongation,and are in good agreement with experimental results;The mechanism of crack initiation and propagation during the tensile process of SiC/AZ91D magnesium based composite material is the initiation of cracks at the interface between particles and matrix,where microcracks connect to form cracks and propagate around the particles,resulting in material fracture.

关 键 词：SiC/AZ91D镁基复合材料 有限元分析 内聚力模型 单轴拉伸 裂纹扩展 

分 类 号：TB331[一般工业技术—材料科学与工程]