在低循环应力时，真空环境中的疲劳断裂次数可比室温大气环境中的高近4倍。
Under lower cyclic stresses, the fatigue cycles to failure in vacuum is increased approximately 4 times than in air.
在低循环应力时，真空环境中的疲劳断裂次数可比室温大气环境中的多2至3倍。
Under lower cyclic stresses, the fatigue cycles to failure in vacuum is increased 2 or 3 times.
在高低周复合疲劳研究中采用了正交试验设计的方法，并以此为基础综合研究了低周应力、高低周应力比、高周循环次数和高周循环频率对复合疲劳寿命的影响及其机理。
Based on the orthogonal test design, this paper studied the effect of low cycle stress, high-low cycle stress ratio , high cycle number and high cycle frequency on complex fatigue life.
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