CFRP@GFRP混杂复合材料杆体在水浸泡环境下的性能演化

碳纤维增强树脂复合材料(CFRP)@玻璃纤维增强树脂复合材料(GFRP)混杂复合材料杆体发挥碳纤维的高力学、疲劳性能与玻璃纤维的低成本、高变形能力等优势，在桥梁与海洋工程中具有巨大应用潜力，如跨海大桥斜拉索。针对CFRP@GFRP混杂复合材料杆体在服役环境下长期性能演化，本文采用加速试验方法研究蒸馏水环境下CFRP@GFRP混杂复合材料杆体的水吸收及界面剪切性能长期演化规律。研究结果表明:混杂复合材料杆体皮、芯层及杆体吸水行为符合Fick定律，GFRP皮层扩散系数最大，CFRP芯层次之，混杂复合材料杆体由于在皮/芯界面层形成吸水屏障而扩散系数最小。浸泡在蒸馏水环境下芯层、皮/芯界面及皮层界面剪切强度下降，这是由于浸泡过程中水分子通过氢键形式与树脂基体结合形成结合水，导致树脂基体发生水解和塑化及纤维/树脂界面脱黏。基于Arrhenius加速理论建立了混杂复合材料杆体在三座典型桥梁服役环境下的界面剪切强度预测模型。 

Property evolution of CFRP@GFRP hybrid composite rod exposed in the distilled water

Carbon fiber reinforced polymer (CFRP)@glass fiber reinforced polymer (GFRP) hybrid composite rod plays the advantages of carbon fiber (such as high mechanical and fatigue performances) and glass fiber (such as low cost and high deformation capacity) and has great application potential in bridge and ocean engineering, such as cross-sea bridge cable. In view of the long-term performance evolution of CFRP@GFRP hybrid composite rod under the service environment, the present paper adopted the experimental acceleration method to study the water absorption and interface shear performance evolution of CFRP@GFRP hybrid composite rod under the distilled water environment. The results show that the absorption behavior of hybrid composite rod is in accordance with Fick law. The diffusion coefficient of glass fiber shell is the largest, carbon fiber core is the second, and the hybrid composite rod is the smallest due to the water absorption barrier between the shell/core interface layer. Immersed in distilled water leads to the decrease of the interface shear strength of core, shell/core and shell layers. This is attributed to the water molecules combined with the resin matrix in the form of hydrogen bond to form the bond water, resulting in the hydrolysis and plasticization of the resin matrix and the debonding of the fiber/resin interface. The prediction model of interface shear strength of hybrid composite rod was established in three typical bridge service environments based on the accelerating theory of Arrhenius.