短纤维增强热塑性树脂复合材料断裂机理研究

 测定了两种短碳纤维(CF)增强热塑性树脂复合材料(CF/PPS和CF/PES-C)的抗拉强度(σ_y)、杨氏模量(E)反断裂韧性(K_(IC)等性能随碳纤维体积分数(0～40vol％)的变化。杨氏模量随CF含量增加而线性增加,Krenchel系数为0.05。σ_y和K_(IC)随CF增多而增大,在25vol％处出现峰值。根据裂纹钉扎模型,结合对负载-位移曲线及断口形貌,着重从界面结合力特征进行分析;计算得两种复合材料的等效裂纹张力分別为26kJ/m和2.1kJ/m。

FRACTURE MECHANISM OF SHORT FIBRE REINFORCED THERMOPLASTIC RESIN COMPOSITES

The properties of two types of short carbon fibre (CF) reinforced thermoplastic resin composites (CF PPS and CF / PES C). such as tensile strength σy. Young's modulus E, and fracture toughness KIC, have been measured for varying volume fraction Vf of CF. It shows that moduli increase linearly as increasing of Vf with a Krenchel's efficiency factor 0.05, whereas σy and KIC rise at first and then peak at Vf of order 0.25. The experiments results have been explained as viewed from characteristics of fibre / matrix adhesion according to the analyses of load-deflection curves and fractography. By using crack pinning model, the effective crack tensions T were calculated for both composites and they are 26kJ / m (for CF PPS) and 2.1kJ / m (for CF/ PES-C) respectively. The localized plastic deformation near fibre / matrix interface provides the major contribution to crack tension.