文档介绍：Journal of Mechanical Strength 2004 ,26(4) :423~427
多轴疲劳裂纹扩展行为研究 X
BEHAVIOR OF MULTIAXIAL FATIGUE CRACK PROPAGATION
尚德广XX 王大康孙国芹蔡能
(北京工业大学机电学院,北京 100022)
SHAN G De Guang WAN G Da Kang SUN GuoQin CAI Neng
( College of Mechanical Engineering and Applied Electronics Technology ,
Beijing University of Technology , Beijing 100022 , China)
摘要利用扫描电镜对多轴比例和非比例加载下的疲劳试样的断口面和外表面进行扫描观测分析。根据薄壁管
拉—扭复合加载试件断口附近表面观测结果,统计其裂纹扩展的位向,研究多轴疲劳裂纹萌生及扩展机理。研究表明,
多轴疲劳裂纹主要是沿最大剪切平面或垂直于管形试样的轴线方向扩展。在多轴比例加载条件下,裂纹分布的分散性
较小。在非比例加载条件下,随着相位差的增大,分散性增大。
关键词多轴疲劳疲劳裂纹萌生与扩展比例加载非比例加载
中图分类号 O346. 2 TH114
Abstract The fracture surfaces of multiaxial fatigue specimens under proportional and non2proportional multiaxial loadings were
observed and analyzed by using a scan electron microscope. According to the observed results near the fracture surfaces , the orientations
of the fatigue crack initiation and propagation were investigated to study the mechanism of multiaxial fatigue crack propagation. The re2
sults showed that most multiaxial fatigue cracks were initiated and propagated along the direction of maximum shear plane or on the direc2
tion perpendicular to the tubular specimen’s axis. For the multiaxial proportional loading , the dispersion degree of fatigue cracks was
low. For the nonproportional loading the dispersion e larger with the phase difference increasing.
Key words Multia