玻璃纤维增强铝锂合金层板单峰过载疲劳寿命性能对比研究

为了研究铝锂合金、纤维金属层板(玻璃纤维增强铝锂合金2/1层板及3/2层板)材料不同加载下的疲劳寿命性能特点,对每种材料进行疲劳寿命试验。通过对每种材料试样施加不同循环特征的循环应力(恒幅循环应力(应力比R=0.06)、单峰拉伸过载、单峰压缩过载),共获得了9种应力-寿命试验数据。使用样本信息聚集原理,拟合出了各材料的P-S-N曲线。通过比较相同材料不同加载方式及相同加载方式不同材料下S-N曲线的差异,结果表明:拉伸过载下3种材料均表现出过载迟滞效应;压缩过载下合金材料表现出加速破坏效应,层板材料表现出一定的延迟效应;不同结构层板之间疲劳性能的优劣与其所受远程应力的大小有一定关系。

Contrast study on fatigue life performance of glass fiber reinforced Al-Li alloy laminates under unimodal overload

In order to study on fatigue life performance of the Al-Li alloy and fiber metal laminates (2/1 laminates and 3/2 laminates of glass fiber reinforced Al-Li alloy) under different loading modes, these materials are subjected to fatigue life test. Each type of the materials is applied to cyclic stress, which has different cycle characteristics (constant amplitude with the stress ratio 0.06, unimodal tensile overload and unimodal compressive overload). Nine kinds of test data on stress life are obtained and P-S-N curve of each material is fitted using the principle of sample polymerization. In addition, the differences of the S-N curve with the same material in different loading modes and different materials in the same loading mode are compared with each other. The results show that all of the three kinds of materials show the effect of overload retardation under tensile overload, Al-Li alloy material exhibits accelerated destruction effect and laminate materials exhibit a delayed effect under compressive overload. The pros and cons of fatigue performance between different structural laminates have a relationship with remote stress.