预固化环氧树脂复合材料构件的共固化研究

Study on co-curing of precured epoxy composite components

针对工字梁等由多个预构件组装后采用先进拉挤工艺共固化的制件,通过对部分构件预固化的方式,在保证后续共固化的黏结性能的前提下,降低表面黏度、提高构件的挺括性以便于构件组装。采用差式扫描量热法(DSC)研究M21C预浸料中树脂的固化动力学,确定预固化工艺,并对不同固化度下制件黏性和层间性能进行研究。结果表明:随着固化度的提高,预浸料的黏性不断下降,可通过改变铺放温度调整预浸料黏性。当预固化度为5.5%时,制件共固化时产生尺寸偏差以及纤维扭曲导致层间性能的下降;当预固化度为20%时,所得制件层间性能最好;当预固化度为32%、45%时,搭接界面不能形成完整的三维网状结构,层间性能大幅减弱。

For multi-component composite beams in the advanced pultrusion technology, such as I-beam, the precuring of process for components can reduce the surface viscosity and improve the stiffness to facilitate the assembly of components under the premise of ensuring the bond property of subsequent co-curing. The curing kinetics of resin in M21C prepreg was studied by differential scanning calorimetry(DSC) to determine the curing process, and the viscosity and interlaminar properties of the product under different curing degrees were studied. The results show that the viscosity of prepreg decreases with the increase of curing degree. The viscosity of prepreg can be adjusted by changing the laying temperature. When the precuring degree is 5.5%, the dimension deviation and fiber distortion will lead to the decrease of interlayer performance. When the degree of precuring is 20%, the interlaminar performance is the best. When the degree of precuring is 32% and 45%, the lap interface cannot form a complete three-dimensional network structure, and the interlayer performance is greatly weakened.