中文摘要：

对有机玻璃进行了不同频率下的低周疲劳试验,得到了相应的S-N曲线和滞后环。试验结果表明,低频时,寿命随频率降低而减小。频率对滞后环面积影响不大,模量随频率降低有较明显降低。分析认为在低频率范围内,频率影响疲劳寿命的原因,有蠕变损伤随频率降低而增加和疲劳强度随应变率减小而降低两个方面。据此,用频率修正法描述不同频率的疲劳寿命并预测了低频段的疲劳寿命,与试验结果吻合较好。

英文摘要：

The fatigue tests of Plexiglas Resist 45 PMMA at different frequencies were carried out and the S-N curves together with hysteresis loops were obtained. The resuhs show that the fatigue life increases with frequency at low frequency domain. Creep damage and mechanical property rate-dependence are two attributes of frequency effect on fatigue life. And the frequency modified approach was employed to describe and estimate the fatigue life under different frequencies at low frequency domain and the calculated results are consistent with the experimental results.