基于材料疲劳特性的零部件低周疲劳试验载荷修正

摘要

航空发动机零部件低周疲劳试验时，由于试验温度与发动机实际工作环境温度不一致，需要对载荷进行修正。基于材料疲劳特性数据，给出了一种疲劳试验的载荷修正方法。该方法可综合考虑循环次数、循环类型、应力集中、循环硬化/软化等材料特性的影响，相比以往依据极限强度进行载荷修正的方法更为全面、合理。同时，给出了基于材料疲劳特性进行载荷修正的流程图，通过实例介绍了该方法在低周疲劳试验载荷修正中的应用。%It is necessary to correct the low cycle fatigue (LCF) test load when the test temperature does not correspond with the working temperature. A load correction method based on material fatigue test results was proposed, and the influence of material characteristics, such as cyclic times, cyclic type, stress concen⁃tration, cyclic hardening/softening effects were considered. Compared with conventional method based on ultimate strength correction, this one exhibits more extensive and reasonable outcomes. The work flow chart for load correction was also given. Finally, the application of this method in actual LCF test was illustrated by an example.