为了研究高温下纤维增强复合材料( FRP) 筋的力学性能，对直径为8 mm 的玻璃纤维增强复合材料( GFRP) 筋进行了高温下的拉伸试验，获得了10 ～ 500℃范围内随着温度升高GFRP 筋的极限强度和弹性模量的衰减趋势; 并结合材料TG/DSC 热学试验结果提出了GFRP 筋在高温下的拉伸本构模型．该三参数拉伸本构模型以纤维和树脂的热学性能为基础，可简化为由树脂玻璃化温度和纤维丝软化/氧化温度控制的二参数模型．经验证，该二参数模型与文中及相关文献中的FRP 筋的高温拉伸试验结果相吻合，具有较强的通用性，可推广应用于其他树脂材料和纤维类型的FRP 筋中．

In order to reveal the mechanical behavior of the fiber-reinforced polymer( FRP) at elevated temperatures,8-mm glass fiber rein-forced polymer ( GFRP) rebars are investigated by the tensile tests at a range of temperatures from 10℃ to 500℃. Thus,the corresponding deterioration tendencies of the ultimate strength and the elastic modulus with the increasing temperature are obtained. Then,based on the results of both the tension tests and the TG/DSC analyses,a tensile constitutive model of three controlled parameters is proposed to describe the GFRP rebars at elevated temperatures. This model considers the material thermal properties of both the resin and the fibers and can be simplified to be a model of two controlled parameters,namely,the glass transition temperature of the resin and the soften /oxidation temperature of the fibers. After the verification,it is found that the model of two controlled parameters is in full agreement with not only the results of the elevated-temperature tensile tests from this paper but also those of FRP rebars from relative papers,and can be generally applied to the FRP rebars with different fiber types and resin mate-rials.