纤维增强铝锂合金层板不同加载方式下的疲劳性能

Fatigue Properties of Fiber Reinforced Al-Li Alloy Laminates Under the Conditions of Different Loading Modes

对纤维增强铝锂合金2/1层板及3/2层板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,应力比为R=-1;高-低加载,Mini-Twist谱载),共获得了6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.通过比较相同加载方式不同材料的S-N曲线的差异,对比分析了不同复合结构的材料疲劳性能的特点.结果表明:在5×10~4~5×10~5寿命范围内,恒幅R=-1及高-低加载载荷下,纤维增强铝锂合金3/2层板疲劳寿命性能均优于2/1层板;Mini-Twist谱载下,纤维增强铝锂合金3/2层板的疲劳性能总体上也优于2/1层板.

The 2/1 laminates and 3/2 laminates of fiber reinforced Al-Li alloy were taken for fatigue life tests. Each type of the materials was applied to cyclic stress,which has different cycle characteristics( constant amplitude with the stress ratio-1,high and lowload and Mini-Twist spectrum load). Six kinds of test data on stress life were obtained and the P-S-N curve of each material was fitted by using the principle of sample polymerization. The S-N curve differences of varied materials in the same loading mode were compared with each other in order to analyze the fatigue performance characteristics of the materials with different compounding patterns. The results showed that in the range of 5 × 10~4~ 5 × 10~5 life,the fatigue life performance of 3/2laminate materials is better than that of 2/1 laminates under constant amplitude and high and lowload; and the fatigue life performance of 3/2 laminate materials is superior to that of 2/1 laminates on the whole under Mini-Twist spectrum load.