铺层方向角偏差对复合材料层板阶梯挖补的拉伸强度影响研究

THE EFFECT OF PLY ANGLE DECLINATION ON TENSILE STRENGTH OF COMPOSITE STEP-LAP REPAIR

针对复合材料损伤结构维修中容易出现的铺层角度偏差,根据实际维修情况建立复合材料层板阶梯挖补结构的有限元计算模型,并通过试验验证了该模型的准确性。基于该有限元分析模型并考虑真实维修过程中可能出现的铺叠误差与基准偏差,分别进行了维修结构的单层与整体铺层方向角偏移的拉伸强度性能分析。结果表明,补片出现小角度方向角偏移时,补片中面层以下的铺层角偏移对于拉伸强度的影响可以忽略,中面层以上的铺层随着偏移角度的增大与越靠近表层的位置,结构整体极限应力逐渐增大,当最表层铺层出现偏移时,对于修补结构拉伸强度的影响较大;附加层在修补结构中受载严重,通用的0°附加层铺设角度不一定适用于所有的修补工况,该分析结论也为实际工程维修提供了很好的指导意义。

According to ply angle declination of composite repair,a three dimensional finite element analysis model is developed for the composite laminated plates with a step-lap repair,which conforms with the results of experiments. Both single ply declination and total plies declination were calculated for the deviation of laying and benchmark. The result of calculations shows that few effects on tensile strength that the declinate ply is under middle plane. The larger angle declination and the position more close to the top ply,the stress level of whole structure is lager. The most serious case occurs on when the angle declination of top ply. The additional ply affords much more loads,and the general 0° angle may not fit for all the repair cases. The conclusion has great significance in directing the engineering practice of composite repair.