C/SiC复合材料连接结构拉脱失效机制  

Pull-out failure mechanism of C/SiC composite connection structure

作　　者：李志强[1] 吴振强[1] 杨凌霄 李尧 刘宝瑞[1] LI Zhiqiang;WU Zhenqiang;YANG Lingxiao;LI Yao;LIU Baorui(Science and Technology on Reliability and Environment Engineering Laboratory,Beijing Institute of Structure and Environment Engineering,Beijing 100076,China;Beijing Institute of Near-Space Aircraft System Engineering,Beijing 100076,China)

机构地区：[1]北京强度环境研究所可靠性与环境工程技术重点实验室,北京100076 [2]北京临近空间飞行器系统工程研究所,北京100076

出　　处：《复合材料学报》2023年第12期6852-6858,共7页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(U20B2002,52202082,12002056)。

摘　　要：通过C/SiC陶瓷基复合材料连接结构单轴拉伸试验,研究了连接结构拉脱失效过程的力学性能变化规律,结合应变测量、高速摄像、CT检测等测试手段从宏观角度和细观角度探究了连接结构拉脱失效过程中的损伤演化过程,确定了陶瓷基复合材料连接结构拉脱失效机制。结果表明:由于螺纹部位沉积及接触状态的差异,导致不同连接结构的初始刚度不一致;随着位移不断增加,连接部位的刚度趋于一致。加载过程中螺纹孔附近受到挤压产生损伤并发生分层现象;当螺纹孔局部的损伤达到一定程度时,连接结构达到最大承载能力,此时随着位移继续增加螺钉开始拉脱,承载能力开始下降,直至螺钉完全拉脱拔出。Through uniaxial tensile test of C/SiC ceramic matrix composite connection structure,the change law of mechanical properties of connection structure during pull-off failure was studied.Combined with strain measurement,high-speed camera,CT detection and other test methods,the damage evolution process of the connection structure during the pull-off failure process was explored from the macro and micro perspectives,and the pull-out failure mechanism of the ceramic matrix composite connection structure was determined.The results show that the initial stiffness of different connection structures is inconsistent due to the difference of the deposition and contact state of the thread.As the displacement increasing,the stiffness of the connecting part tends to be consistent.Damage and delamination occur when the threaded hole is squeezed during loading.When the local damage of the threaded hole reaches a certain degree,the connecting structure reaches the maximum bearing capacity.At this time,as the displacement continues to increase,the screw begins to pull out,and the bearing capacity begins to decline until the screw is completely pulled out.

关 键 词：C/SIC复合材料 连接结构 拉脱失效 损伤演化 CT检测 

分 类 号：TB332[一般工业技术—材料科学与工程]