固化压力对厚L形CFRP单向板纤维分布影响的实验研究

EXPERIMENTAL STUDY ON EFFECT OF CURING PRESSURE ON FIBER DISTRIBUTION OF THICK L-SHAPED CFRP UNIDIRECTIONAL LAMINATES

采用热压罐工艺制备了厚L形CFRP单向板,通过对其宏细观结构形貌的分析,研究压力对厚L形CFRP单向板厚度和纤维分布的影响。结果表明:采用热压罐工艺制备厚L形CFRP单向板时会出现褶皱和厚度不均匀等缺陷,预浸料层间有明显的树脂富集带。通过增加固化压力,可以降低树脂富集带的宽度,抑制厚L形CFRP单向板表面褶皱的产生,增加压实量,但会导致不同截面间纤维体积分数差异变大,外侧纤维梯度分布区变大;增加压力还会导致曲面段变薄且靠近底部纤维含量变高,靠近模具侧树脂有向平板/曲面段过渡区流动聚集的趋势。

The thick L-shaped unidirectional carbon fibre reinforced polymer composite laminates(CFRP)were manufactured by the autoclave process.Based on the analysis of macroscopic and microscopic structure morphology,the effects of autoclave pressure on the laminate thickness and fiber distribution were estimated.The results show that the out-of-plane wrinkling and nonuniform thickness distribution arise in the thick L-shaped CFRP unidirectional laminates manufactured by the autoclave process.The resin-rich regions are present between the prepregs.By increasing the autoclave pressure,the thickness of resin-rich regions between prepregs and the wrinkles in the thick L-shaped CFRP unidirectional laminates can be reduced.The thickness compaction,the fiber content difference between different sections and fiber content gradient in the region closing to the bleeder increase with the increasing the autoclave pressure,the thickness of corner section becomes smaller than that of the flat section,and fiber content near mold surface becomes higher if a high autoclave pressure is applied.Close to the mold side,the resin tends to aggregate into the flat/corner transition region.