新型纤维金属混合层板结构的疲劳裂纹扩展与分层行为

Fatigue Crack Propagation and Delamination Behavior of Advanced Fiber Metal Hybrid Laminate

为了研究一种新型混合层板的损伤容限性能,针对两种铺层混合层板结构进行了应力比R=0.1,-1下两种锯切缺口尺寸试样的疲劳裂纹扩展试验,对比分析了获得的裂纹扩展a-N曲线数据,并通过对试样进行腐蚀去层,研究了层板的各层分层形态。结果表明,在应力比R=0.1时该新型混合层板疲劳裂纹扩展性能明显优于铝合金板;预浸料两侧添加胶膜比不添加胶膜会导致较好的疲劳裂纹扩展性能;由于裂纹桥接机制作用,锯切缺口尺寸较短层板试样比较长层板试样有较好的裂纹扩展性能;层板中心层铝板较其它层铝板裂纹扩展明显滞后;内层铝板与预浸料间沿裂纹方向呈近似三角形分层。

To study damage tolerance behavior of one kind of advanced hybrid laminate, this article accomplished fatigue crack propagation test under R = 0.1 or - 1 for two kinds of saw-cut length and two kinds of lay-up, compared and analyzed α-N data, obtained the delamination shape between each layers by etching the aluminium sheet. The result indicates that this advanced hybrid laminate obvi- ously displays a better fatigue crack propagation property than aluminium sheet under R = 0.1. The laminate with adhesive film around the prepreg performs a better fatigue crack propagation property than the laminate without adhesive film around the prepreg. The specimen with shorter saw-cut length shows a better fatigue crack propagation property than the specimen with longer saw-cut length for the bridging mechanism. Crack in central aluminium sheet is shorter than the others. The delamination shape between inner aluminium sheet and prepreg presents a triangle.