复合材料层合板斜切型挖补修理试验

Experimental study of composite laminate adhesively tapered-scarf repair

为研究拉伸载荷作用下不同挖补角和附加层数对复合材料胶接挖补修理接头刚度、强度、失效模式及关键位置应变变化的影响,开展了复合材料层合板斜切型挖补修理接头拉伸试验.采用一种碳纤维织物增强树脂复合材料作为母板与补片材料,一种改性环氧树脂胶膜作为胶层材料,设计了斜切挖补角分别为1.8°、2.6°、3.5°、4.4°,附加一附加层或二附加层的斜切型挖补修理试验件.拉伸试验结果表明,在1.8°至4.4°挖补角范围内,所研究的接头刚度和强度随挖补角的增大而减小.附加层数的增加能够有效提升接头的刚度及强度.接头的失效可以概括为四种模式,与挖补角及附加层数目相关。接头关键位置点的纵向应变变化能够动态反映接头的失效过程.

Tensile experiments on adhesively scarf-repaired composite laminate joints were conducted, for analyzing the stiffness, strength, failure modes and key positions＇ strain distributions of the joints with different scarf angles and extra ply numbers subjected to unidirectional tensions. A kind of carbon fiber woven reinforced composite was applied to fabricate the base laminates and repair patches, and a kind of curing modified epoxy supported film adhesive was used as adhesive layer, designing a series of specimens with one extra ply or two extra plies, of which scarf angles are equal to 1.8°, 2.6°, 3.5° and 4.4°, respectively. Tensile experiment results show that stiffness and strength of the joints are negatively related to scarf angles in the range from 1.8° to 4.4°. Adding extra plies helps enhancing the stiffness and strength of the joints. The failure modes of the joints can be summarized into four types, which are related to scarf angles and extra ply numbers. The longitudinal strain changing at the key points of the joints can be applied to reflect the failing process of the joints dynamically.