铺层角度对形状记忆复合材料层合板性能的影响

摘要

Micro-buckling and shape memory performances of shape memory composite(SMC) laminates which have different ply orientation were studied. Firstly,the fiber compressive strain on the compressive area of ±θlaminates under large flexural deformation above Tg was theoretically analyzed,then the contours of out-of-plane micro-buckling and the micro-buckling of the outermost fibers of the compressive area were experimentally observed for [04],[±22.5]S,[±45]S and [±67.5]S laminates. It is found that under the same flexural radius,the increase of the ply angle could significantly reduce the micro-buckling degree,which can also reduce the possibility of kink-deformation damage. Finally,the influences of gradually increasing the proportion of ±45° ply within the unidirectional laminates of full 0° ply and changing the order of plies on the micro-buckling degree and the shape recovery ratio are researched through experiments. The results show that the increase of the ±45° ply can significantly reduce the micro-buckling degree,while changing the position of ±45° ply has a little influence on the micro-buckling degree. Below 60%in the proportion of the ±45° ply has little influence on the shape recovery ratio,however,once the proportion of the ±45° ply is over 80%,the shape recovery ratio is significantly reduced.%对不同铺层角度的形状记忆复合材料(SMC)层合板的微屈曲及形状记忆性能进行了研究。首先对±θ铺层的层合板在玻璃化转变温度以上发生弯曲变形时受压区的纤维应变进行理论分析。实验观察了[04]，[±22.5]S，[±45]S和[±67.5]S等4种铺层方式的SMC层合板在弯曲变形下的面外微屈曲及受压区最外层纤维微屈曲形貌，发现在同等弯曲半径下，铺层角度的增大可显著降低微屈曲的程度，且可同时降低折曲破坏出现的可能性。最后，研究了在全0°铺层的单向板内逐步增加±45°铺层的比例并改变铺层顺序对微屈曲程度及形状记忆回复率的影响。结果表明，增加±45°铺层的比例可显著降低微屈曲程度，同时改变±45°铺层的位置对微屈曲程度的影响不大。60%以下的±45°铺层比例对形状记忆回复率影响较小，一旦±45°铺层比例超过80%，形状记忆回复率显著降低。