中南大学学报（自然科学版）2025，Vol.56Issue(5)：1784-1794,11.DOI:10.11817/j.issn.1672-7207.2025.05.007
应力比对十字型复合材料试样疲劳行为的影响
Influence of stress ratio on fatigue behavior of cruciform composite specimens
摘要
Abstract
The evolutionary characteristics of fatigue behavior for glass fiber reinforced composites under the synergistic effect of stress multiaxiality and stress ratio were investigated,thus clarifying the stress ratio effect on the multiaxial fatigue performance in composites.Firstly,a center-thinned cruciform specimen with concave chamfer was chosen as the research object,and fatigue test of cruciform specimen was carried out on a planar biaxial test rig.Secondly,the digital image correlation(DIC)technology and the virtual extensometer method were used to measure the strain in the gauge zone of cruciform specimen in a real-time,high efficient,and automated manner.The real-time strain was taken as the only parameter for the control of fatigue test.Thirdly,the crack propagation process in the gauge zone of cruciform specimens was accurately monitored by white light-assisted imaging technology.Combined with finite element simulation analysis,the crack propagation rate under different loading conditions was calculated.Finally,the crack density evolution curves,crack propagation rate curves,and S-N life curves were plotted based on the fatigue test data to systematically analyze the effect of stress ratio on the multiaxial fatigue characteristics of the composites.The results show that increasing the stress ratio can significantly add the number of cycles for crack initiation and crack density up to 0.6 mm-1,slow down the crack propagation,and prolong the life.In the range of positive stress ratios,the multiaxial stress state only influences the damage propagation speed of the specimen and does not alter its damage evolution mechanism.The increase in the in-plane shear stress markedly accelerates fatigue in cruciform specimens.关键词
复合材料/十字型试样/裂纹扩展/疲劳寿命/应力比/应力多轴度Key words
composites/cruciform specimens/crack propagation/fatigue life/stress ratio/stress multiaxiality分类
通用工业技术引用本文复制引用
马辉东,李德旺,杨鑫源,白学宗,安宗文..应力比对十字型复合材料试样疲劳行为的影响[J].中南大学学报（自然科学版）,2025,56(5):1784-1794,11.基金项目
国家自然科学基金资助项目(52365017) （52365017）
兰州市青年科技人才创新项目(2023-QN-35) （2023-QN-35）
兰州理工大学优秀博士学位论文培育计划项目(2022)(Project(52365017)supported by the National Natural Science Foundation of China （2022）
Project(2023-QN-35)supported by the Youth Science and Technology Talent Innovation Project of Lanzhou City （2023-QN-35）
Project(2022)supported by the Incubation Program of Excellent Doctoral Dissertation-Lanzhou University of Technology) （2022）
