高强度玻璃纤维增强聚合物基复合材料湿热老化机理及力学行为

Hygrothermal Aging Mechanisms and Mechanical Behaviors of High-strength Glass Fiber Reinforced Polymer Composites

相对碳纤维增强聚合物基复合材料,高强度玻璃纤维增强聚合物基复合材料对湿热环境敏感更为强烈,湿热环境容易导致高强度玻璃纤维增强聚合物基复合材料力学性能出现显著下降。本文对两种浸润剂状态的高强度玻璃纤维进行水浸试验和性能试验,获得了高强度玻璃纤维湿热前后的性能数据。通过对两种浸润剂状态的高强度玻璃纤维增强的聚合物基复合材料分别进行吸湿及力学性能试验研究,得到了复合材料典型湿热-时间曲线及典型力学性能数据。并结合宏微观断口图,研究了湿热老化机理和损伤破坏机理。高强度玻璃纤维水浸试验结果表明湿热过程中纤维表面浸润剂溶出使得纤维曝露,进而破坏了其组织结构,导致力学性能下降。高强度玻璃纤维增强聚合物基复合材料拉伸应力—应变曲线在室温干态环境下呈现典型非线性特征,在湿热环境下基本为线性。室温干态下的开孔拉伸载荷-位移曲线在损伤演化过程中具有特殊的“上下振荡起伏”的特点。宏微观断口显示室温环境下基体拉伸破坏模式为主要破坏模式,而湿热环境下下纤维与基体的剪切破坏为首要破坏模式。

Compare to the carbon fiber reinforced polymer composites,high-strength glass fibers and their polymer composites are more sensitive to hygrothermal environments.The hygrothermal environment is easily to cause the significant decreases in the mechanical properties of high-strength glass fibers and their polymer composites.In this paper,water immersion tests and property tests were conducted on the high-strength glass fibers with two types of impregnating agents,and the performance data of the high-strength glass fibers before and after hygrothermal was obtained.The absorption and mechanical properties of the polymer composites reinforced by high-strength glass fibers with two types of impregnating agents were studied,and typical hygrothermal-time curves and mechanical data were obtained.Combined with macroscopic and microscopic fracture diagrams,the hygrothermal aging mechanism and damage failure mechanism were studied.The water immersion test results of high-strength glass fibers show that the fiber surface wetting agent dissolves during the process of hygrothermal aging,which causes the fibers to be exposed,and then destroys the structures of the fibers,resulting in the decrease of mechanical properties.The tensile stress-strain curves of high-strength glass fiber composites show typical nonlinear characteristics in the room conditions,and are basically linear in hot and hygrothermal conditions.In the process of damage evolutions,the open-hole tensile load-displacement curves at the room temperature have a special characteristic of“up and down oscillation”.The macro and micro fractures show that the tensile failure mode is the main failure mode at the room temperature,while the shear failure mode of fibers and matrix is the main failure mode at the hot and humid environment.