疲劳荷载作用下抗弯加固RC梁FRP应变分析

Analysis of FRP strain of strengthened RC beams under cyclic bending loads

根据一系列常幅疲劳试验,分析了抗弯加固RC梁中FRP疲劳应变的变化规律和关键影响因素.FRP疲劳应变随着荷载水平的增加而增加,与加固构件挠度变形量成较好的线性关系.在疲劳加载初期由于混凝土裂缝的出现导致加固构件挠度的增加,FRP应变快速增加;随后在大部分的疲劳寿命期内FRP应变变化很小,略有下降,表现出良好的抗疲劳力学性能.

Based on a series of fatigue tests, the change laws and the main influence factors of FRP strain of strengthened RC beams under cyclic bending loads were analyzed. FRP fatigue strain which increased with the increase of load level was linear with the deflection of the strengthened RC beams,FRP strain increased rapidly at initial loading because of the increaing in the deflection of the strengthened RC beams caused by the occurrense of concrete cracks. Then in the main phase of the fatigue lives FRP strain changed little, showing good anti -fatigue mechanical properties.