针对聚合物基复合材料力学性能的应变率依赖性问题，探讨、量化了复合材料静态和疲劳性能的应变率强化效应，提出了变频加载下复合材料剩余强度和疲劳损伤的评估方法。首先，分别对包含和不包含静强度的疲劳寿命数据执行幂律S-N曲线拟合，分析静强度和疲劳寿命的加载频率敏感性，进而通过引入应变率强化系数，量化了应变率对材料强度的强化程度，确保了复合材料力学性能表征数据的应变率一致性。其次，利用强度储备概念构建了独立于应力水平的概率型剩余强度模型，该模型能仅用一组模型参数预测任意应力水平下的强度退化过程。最后，基于所开发的模型和公开数据进行了变频加载的剩余强度预测，结果表明，升频加载和降频加载造成的累积损伤分别为0.323、0.493，与试验数据相差不超过5%，预测结果可靠。

To address the strain-rate dependence of the mechanical properties in polymer matrix composites， the strain-rate strengthening effect on the static and fatigue properties of such composites is investigated， quantified， and a method for assessing residual strength and fatigue damage of these composites under variable-frequency loading is proposed. Firstly， power-law S-N curve fitting was performed on the fatigue life data with and without static strength respectively， and the loading frequency sensitivity of static strength and fatigue life was analyzed. Besides， the strengthening magnitude of strain rate on material strength was quantified by integrating strain rate strengthening coefficient， which ensured the strain rate consistency of the data for characterizing the mechanical properties of the composite materials. Secondly， a probabilistic residual strength model independent of stress level was derived using the concept of strength reserve， which can predict the strength degradation process at any stress level with only one set of model parameters. Finally， based on the developed model and published data， the residual strength prediction under variable frequency loading was carried out. The results show that the cumulative damage caused by the ascending-frequency and descending-frequency loading are 0.323 and 0.493 respectively， which are less than 5% different from the experimental data， and the prediction results are reliable.