改性碳/碳复合材料疲劳试验后的断裂行为及剩余强度预测  

Fracture Behavior and Residual Strength Prediction of Modified Carbon/Carbon Composite after Fatigue Test

作　　者：陆文韬[1] 张宏宇[2] 林位麒 赵华[1] LU Wentao;ZHANG Hongyu;LIN Weiqi;ZHAO Hua(School of Mechanics and Aerospace,Southwest Jiaotong University,Chendu 610031,China;Key Laboratory of Space Physics,China Academy of Launch Vehicle Technology,Beijing 100076,China)

机构地区：[1]西南交通大学力学与航空航天学院,成都610031 [2]中国运载火箭技术研究院,空间物理重点试验室,北京100076

出　　处：《机械工程材料》2023年第2期96-102,共7页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(11872319)。

摘　　要：对改性碳/碳复合材料多层板试样在应力比0.1,-1下进行一定循环周次的疲劳试验后,再进行单向拉伸试验,测得复合材料的平均剩余强度;选择疲劳后具有规整穿透型裂纹的试样,基于其裂纹形貌在Abaqus软件中建立有限元计算模型,计算得到该试样的临界应力强度因子,并以此作为断裂判据对其余试样的剩余强度进行预测,并与各试样的实测剩余强度进行对比。结果表明:试样断口上的疲劳裂纹均呈I型断裂模式,在应力比0.1,-1下的剩余强度均值分别为252.3,258.8 MPa;疲劳后具有规整穿透型裂纹的试样的临界应力强度因子为630 MPa·mm^(1/2),以此作为断裂判据得到其余试样的预测剩余强度与实测值的相对误差均小于5.5%,说明该方法预测精度较高。The multi-layer plate specimens of a modified carbon/carbon composite were subjected to fatigue tests for a certain number of cycles at a stress ratio of 0.1 and-1,and then were subjected to uniaxial tensile tests to measure average residual strength of the composite.The specimen with regular penetrating cracks after fatigue was selected.On the basis of crack morphology of the specimen,a finite element calculation model was established in Abaqus software,and the critical stress intensity factor of the specimen was calculated.By using the critical stress intensity factor as a fracture criterion,the residual strength of the remaining specimens was predicted and compared with the measured residual strength of each remaining specimen.The results show that the fatigue cracks on fracture surface of the specimens were all I-type fracture mode,and the average residual strength at the stress ratio of 0.1 and-1 was 252.3 MPa and 258.8 MPa,respectively.The critical stress intensity factor of the specimen with regular penetrating cracks after fatigue was 630 MPa·mm^(1/2).The relative errors between the predicted residual strength and the measured values of the remaining specimens were all less than 5.5%,indicating that the prediction accuracy of this method was high.

关 键 词：碳/碳复合材料 疲劳 应力强度因子 剩余强度 

分 类 号：TB332[一般工业技术—材料科学与工程]