复合材料变厚层板热压成型缺陷类型与成因实验研究

采用热压机工艺与热压罐工艺两种成型方法制备了玻璃纤维/环氧 648 变厚度层板 , 研究了两种工艺下缺陷的形成机制及铺层方式和变厚梯度对缺陷程度和分布的影响。结果表明 : 纤维分布不均、 富树脂、 分层是主要缺陷类型 , 其中纤维分布不均由树脂二维流动引起 , 并与纤维不连续区、 纤维层渗透特性以及外压的均匀性有关; 富树脂主要是纤维的不连续性造成的 ; 而分层缺陷与纤维分布和热膨胀各向异性紧密相关。研究结果对变厚度复合材料层板的缺陷消除和成型质量控制有重要的指导意义。 

Experimental study on type and cause of defects in variable thickness composite laminates during hot pressing process

The glass fiber/ epoxy resin 648 variable thickness laminates were prepared with the hot press and the autoclave methods. The mechanism of defect formation in the two processings was investigated , and the effect s of the lay-up type and ply-drop gradient on the extent and dist ribution of defect s were studied. The result s show that fiber asymmet ric dist ribution , rich resin and delamination are the major types of defect s. Two dimensional resin flow result s in fiber uneven dist ribution , which is influenced by the fiber discontinuous area , permeability of the fiber bed and the uniformity of applied pressure. Rich resin result s f rom the fiber discontinuous area. Delamination has close  relations with fiber dist ribution and anisot ropy in thermal expansion. The result s are valuable for eliminating the defect s and cont rolling the processing quality in variable thickness laminate st ructures.