大气或氯离子浸泡环境下玻璃纤维增强复合材料蠕变试验和理论研究

EXPERIMENTAL AND THEORETICAL STUDY OF CREEP BEHAVIOR OF GLASS FIBER REINFORCED POLYMER(GFRP) COMPOSITES IN ATMOSPHERIC AND CHLORIDE ION ENVIRONMENT

分别在大气与氯离子浸泡环境下,测试不同试验周期下玻璃纤维增强不饱和树脂基复合材料(GFRP)片材的蠕变,分析不同环境和应力水平对GFRP蠕变的影响。研究结果表明:GFRP的蠕变率在试验前期增长较快,后期较慢;GFRP蠕变特性与加载应力水平、环境有关,相同环境下加载应力越大,蠕变应变增量越大;在相同应力水平作用下,氯离子环境下GFRP蠕变应变大于大气环境;水分的吸收和扩散使得树脂体积膨胀产生剪应力,与玻璃纤维发生脱黏,引起界面破坏,从而降低GFRP的黏弹性能;树脂与水分子发生化学反应,导致树脂中的化学介质解析出来,其基体中出现坑洼,破坏纤维与树脂界面的完整性,进而降低GFRP的黏弹性能。基于Kelvin标准线固性蠕变模型,考虑环境、应力变化幅值,提出GFRP蠕变预测模型及其适用性。

To investigate the effect of different environment and stress levels on creep of glass fiber reinforced polymer composite （ GFRP） , its creeps under the effect of atmospheric and chloride ion environment during different test periods were measured.The results showed that the rate of creep increases fast initially and slower in late period.The property of GFRP was influenced by environment and stress level,in the same environment,the higher stress level,the more increment of creep;in the same stress level, the increment of creep of GFRP in chloride ion was higher than that in atmosphere;water absorption and diffusion in the resin resulted in a volumetric expansion leading to microcracks, and then decreased the properties of it＆#39;s viscoelasticity.There was a chemical reaction of the resin with the water molecules,and the chemical agents were easily leached out, which led to the occurrence of pits,then the bonding between the fiber and the matrix broke.The creep prediction model of GFRP and its applicability were proposed, based on the standard linear solid model theory by Kelvin, considering various environment and stress range.