为揭示连接孔垂直度误差对航空复合材料连接性能的影响规律,对准各向同性碳纤维环氧树脂复合材料板进行了单钉单剪试验研究。以极限承载强度、弦刚度、2%偏移承载强度为指标研究连接孔的倾斜角度、倾斜方向以及螺栓扭矩对接头承载性能的影响规律。试验结果表明:当连接孔倾斜角度从0°增加到4°时,接头弦刚度增大10%~40%,极限承载强度下降9%~12%;连接孔倾斜方向对极限承载强度影响甚微,却可使接头弦刚度产生20%~30%的变化;增加螺栓扭矩可以有效提高极限承载强度,但对接头刚度无明显影响;连接孔倾斜角度越大,则螺栓扭矩的增大对2%偏移承载强度的强化效果越不明显。
A single-lap single-bolt experimental study of quasi-isotropic lay-ups carbon fiber/epoxy laminates is conducted to assess the effects of perpendicularity error of hole on the bearing properties of composites in aerospace.The effects of the tilt angle,tilt direction of hole and bolt torque on the bearing properties of the joints are investigated by comparing the bearing strength,chord stiffness as well as 2% offset bearing strength.It is found that when the tilt angle of hole increases from0°to 4°,the chord stiffness of joints increases from 10% to 40%,while the bearing strength of joints decreases by 9%-12%.The bearing strength of joints is not influenced by the tilt direction of hole.However,the chord stiffness changes about20%-30% as the tilt direction of hole changes.Higher bolt torque can effectively improve the bearing strength of joints,but has little effect on chord stiffness.With the increase of the tilt angle of hole,the effect of the bolt torque on 2% offset bearing strength decreases.