加载频率对低循环疲劳寿命影响之初探

A Study on the Effect of Loading Frequency on Fatigue Life in Low Cycle

在低循环疲劳试验中，同一应变水平下的试样表面温升及控制应变速率随加载频率增加而升高。在某一较高的频率范围内，疲劳寿命与加载频率及试样温升几乎无关，但当频率低于某一值时，疲劳寿命则有下降的趋势，如若试验在较高频率下进行，而后对疲劳寿命再做适当修正，也可得低频率下的疲劳寿命，这可明显地提高工效，节省费用，具有重要的现实意义。

The surface temperature and strain rate of a specimen increases a with the increase of loading frequency at a certain strain amplitude in Iow cycle fatigue test.In a certain range of higher frequences the fatigue life hardly depends on loading frequency and specimen temperature. However,when the loading frequency is lower than a certain value,the fatigue life will tend to de-crease. It is found that a higher the fatained life in low loading frequency can also be obtained if the experiment is made under higher frequencies and it is properly correted,which apparently time and raises work efficiency.Therrefore,it has an important practical significance.