单向玻璃纤维／树脂复合材料的Ⅱ型断裂研究

MODE Ⅱ DELAMINATION OF A UNIDIRECTIONAL GLASS FIBER/EPOXY COMPOSITE

本文研究了长玻璃纤维强化的树脂基复合材料的Ⅱ型断裂韧性及裂纹扩展速率。作者使用了超声波技术来测定复合材料的弹性模量，测定的结果与混合定律计算的结果吻合的很好。ＥＮＦ三点弯曲试样被用来测定ＧⅡｃ和ｄａ／ｄｎ与ΔＧⅡ的关系。通过理论分析，梁内剪应力对用梁理论计算出的ＧⅡ的影响误差约为３％。对断口的分析显示了不同的断裂类型会带来不同的微观断口形貌。

The mode Ⅱ delamination of a glass fiber reinforced epoxy composite was studied by both static and fatigue tests. The ultrasound technic was used to measure the elastic moduli of studied composites. The measured results are proved to agree well with that obtained with mixed rulers. ENF specimens were used to obtain G ⅡC and the relationship between d a /d N and Δ G Ⅱ . By theoretical analysis, the G Ⅱ value calculated with classical beam theories is 3% lower than the exact value.The observation under SEM shows that different fracture modes can result in different microscopic aspects of rupture surface.