Fiber metal laminates, as the new generation of aircraft structural materials, are widely concerned by material researcher. This paper presents a study on the life prediction problems of fiber-reinforced Al–Li alloy laminates under spectrum loading by applying the cumulative damage and residual strength models. Firstly, fatigue life performance of the laminate materials is tested under different loading cases. Then, the most advanced damage accumulation and residual strength models are summarized, which is applied to composite laminates. Some models are directly abandoned because the data needed for fitting model cannot be obtained by this experiment or the model formulation is prevented directly to the application for the spectrum blocks with free loading. Meanwhile, a cumulative damage model considering residual strength is modified accordingly based on the characteristics of life prediction under spectrum loading. To study the impacts of these models on the fatigue life prediction for fiber reinforced Al–Li alloy laminate under spectrum loading, the predicted accuracy of these models will be compared by applying them to life prediction problems of 2/1 laminate and 3/2 laminate. Results show that compared with other models, modified model improves the prediction accuracy especially for 3/2 laminate.

中文翻译：

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光谱载荷下影响纤维增强铝锂合金层压板寿命预测的损伤判据

纤维金属层压板作为新一代飞机结构材料，受到材料研究人员的广泛关注。本文通过应用累积损伤和残余强度模型，研究了纤维增强铝锂合金层压板在频谱载荷下的寿命预测问题。首先，对不同载荷工况下层压材料的疲劳寿命性能进行了测试。然后，总结了最先进的损伤累积和残余强度模型，并将其应用于复合材料层合板。部分模型由于本次实验无法得到拟合模型所需的数据，或者模型的制定直接无法应用于自由加载的谱块，直接放弃了一些模型。 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 同时，根据谱载荷下寿命预测的特点，对考虑残余强度的累积损伤模型进行相应修改。为了研究这些模型对光谱载荷下纤维增强铝锂合金层板疲劳寿命预测的影响，将这些模型应用于2/1层板和3/2层板的寿命预测问题来比较这些模型的预测精度. 结果表明，与其他模型相比，修正模型提高了预测精度，尤其是对于3/2层板。将通过将这些模型应用于 2/1 层压板和 3/2 层压板的寿命预测问题来比较这些模型的预测精度。结果表明，与其他模型相比，修正模型提高了预测精度，尤其是对于3/2层板。将通过将这些模型应用于 2/1 层压板和 3/2 层压板的寿命预测问题来比较这些模型的预测精度。结果表明，与其他模型相比，修正模型提高了预测精度，尤其是对于3/2层板。