摘要
二维编织碳化硅纤维增强碳化硅复合材料(2D-SiC_(f)/SiC)在航空领域中得到广泛使用,然而该材料层间强度低,使其易萌生层间裂纹,引起分层破坏。为此,本工作采用楔形双悬臂梁法(W-DCB)和悬臂梁法(DCB)开展了层间Ⅰ型断裂试验,获得了2D-SiC_(f)/SiC的层间裂纹驱动的加载数据,得到了其裂纹端口张开力及张开位移变形曲线。在试验加载过程,通过光学显微镜监测了视觉裂纹扩展过程,探究了2D-SiC_(f)/SiC的层间I型裂纹扩展规律。结合理论分析和裂纹视觉特征解释了加载曲线拐点及其他特征点的断裂力学含义。利用扫描电子显微镜分析了2D-SiC_(f)/SiC的层间断面特征,揭示了断面分层裂纹扩展机制。结果表明:W-DCB方法测量的2D-SiC_(f)/SiC层间Ⅰ型初始能量释放率与DCB方法等效;2D-SiC_(f)/SiC层间Ⅰ型断裂过程中,裂纹端口变形曲线的多峰性不符合经典线弹性断裂力学预测的加载峰后特征,反映了2D-SiC_(f)/SiC层间约束关系的复杂性;层间断面为结构性非完全损伤,发生了局部纤维桥连现象。
Two-dimensional braided silicon carbide fiber reinforced composite material(2D SiC_(f)/SiC)is widely used in the aerospace field.However,owing to its weak interlaminar mechanical properties,this material is prone to initiation of interlaminar cracks and delamination failure.Therefore,a comparative study on the Wedge-loaded Double Cantilever Beam method(W-DCB)and the classical Double Cantilever Beam method(DCB)was conducted.The loading data of interlaminar crack-driving were obtained,and the relationship curve of crack opening force and opening displacement were obtained.During the loading,the visual crack propagation process was monitored through an optical microscope,which was to explore the interlaminar crack growth behaviors.Combined the theoretical analysis and the visual characteristics of the crack,the meaning of the inflection point and other characteristic points of the relationship curve is explained.What’s more,scanning electron microscope was used to analyze the characteristics of the interlaminar fracture surface to reveal growth mechanism of the delamination crack in the fracture surface.The results show that the W-DCB method is equivalent to the DCB method in measuring the initial energy release rate of interlaminar Mode Ⅰ fracture in 2D-SiC_(f)/SiC;In terms of 2D-SiC_(f)/SiC interlaminar Mode Ⅰ fracture,the multi-peak characteristic of deformation curve is not according with the post-peak loading curve predicted by classical linear elastic Fracture mechanics,which reflects complexity of interlaminar constraint relationship.The interlaminar section is structurally non-completely damaged,but still emerging local fiber-bridgings.
作者
师维刚
张超
李玫
王晶
张程煜
SHI Weigang;ZHANG Chao;LI Mei;WANG Jing;ZHANG Chengyu(NPU-SAS Joint Research Center,School of Materials,Northwestern Polytechnical University,Xi’an 710072,China;Institute of Extreme Mechanics,Northwestern Polytechnical University,Xi’an 710072,China;School of Materials,Northwestern Polytechnical University,Xi’an 710072,China;Department of Mechanics,College of Science,Xi’an University of Science and Technology,Xi’an 710600,China)
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2024年第1期45-50,共6页
Journal of Inorganic Materials
基金
国家自然科学基金(U2241239,12102336)。
