阶梯式胶接连接复合材料连接效率评价

Evaluation of bonding efficiency for adhesively bonded step-lap joints of composite laminates

对阶梯式胶接连接复合材料层合板的拉伸性能和弯曲性能进行了试验研究,分析了铺层角度、搭接长度对胶接连接后层合板拉伸和弯曲强度连接效率及失效模式的影响。试验结果表明,搭接长度对试件的刚度影响较小,强度影响较大,随着搭接长度的增加,连接效率逐渐增大;[0/90]4S铺层试件拉伸和弯曲强度的最大连接效率分别为23.5%和34.7%,[±45]4S铺层试件拉伸和弯曲强度最大连接效率分别为37.2%和106.0%;与斜接式胶接连接复合材料相比,阶梯式胶接连接效率低于斜接式胶接连接效率,[±45]4S铺层试件连接效率优于[0/90]4S铺层试件连接效率;拉伸试件主要的失效模式为胶层失效、分层失效和纤维撕裂。搭接长度较小的弯曲试件容易在胶接处断开,出现胶层失效和纤维撕裂,搭接长度较大的弯曲试件胶接处未完全断开,出现分层失效。

The tensile property and the bending property of adhesively bonded step-lap joints have been analyzed experimentally.This study is to investigate the effect of the lay-up,lap length on the bonding efficiency and failure mode of adhesively bonded CFRP joints.The lap length has little effect on the stiffness of the specimen,but it has a great effect on the strength of the specimen, where the bonding efficiency increases with the increase of the lap length;The maximum bonding efficiency of tensile and flexural strength of [0/90]4s specimens was found to be 23.5%and 34.7%.The maximum bonding efficiency of [±45]4s specimens was 37.2% and 106.0%.The bonding efficiency of scarf-lap joints is higher than that of the step-lap joints.The bonding efficiency of [±45]4s specimens are better than [0/90]4s specimens.The main failure modes of tensile specimens include cohesive failure,delamination failure and fiber-tear.Bending specimens with smaller lap length are disconnected at the adhesive layer,where the failure is cohesive failure and fiber-tear.Bending specimens with longer lap length will not be completely disconnected,and the failure is delamination failure.