关键词: FRPM管涵, 变形率, 疲劳性能, 剩余刚度理论

Abstract: The FRPM pipe culvert fixture is developed according to the force characteristics of the pipe culvert, and the specimens with a deformation rate of 0%, 1%, 2% and 3% are subjected to 10 times, 500 000 times, 1 million times and 2 million times of cyclic loading. The influence of deformation rate on the fatigue performance of FRPM pipe culvert is andyzed. According to the residual stiffness theory linear fatigue damage theory and fatigue test results, the residual stiffness fatigue life prediction model of FRPM pipe culvert is established. The main conclusions are as follows: ①The deformation rate affects the load-bearing capacity of the specimen. The greater the deformation rate, the lower the load-bearing capacity of the specimen after the fatigue test. ②The increase in the number of cyclic fatigue loads can reduce the FRPM pipe culvert when the deformation rate is 0%, after 2 million times of fatigue load, the pipe stiffness of FRPM pipe culvert specimen drops from 50.71 kPa to 46.05 kPa, a decrease of 10.12%. ③After fatigue load, the deformation rate reduces the bearing capacity and stiffness of the pipe culvert. For a pipe culvert with a deformation rate of 3%, after 2 million fatigue loads, the stiffness of the pipe decreases by 24.44%. ④The strain growth rate at each measurement point of the specimen is positively correlated with the number of fatigue loads. The greater the deformation rate, the lower the load-bearing capacity after the fatigue load, and the more the number of fatigue actions, the greater the reduction in its load-bearing capacity. ⑤Establishing a fatigue life prediction model based on residual stiffness through the fatigue life prediction model. When the deformation rate is 0%, 1%, 2% and 3%, the fatigue life of FRPM pipe culvert, when the deformation rate is 0%, the fatigue life of FRPM pipe culvert is 12 529 600 times, and when the deformation rate is 3%, the fatigue life of FRPM pipe culvert was 6 937 100 times. The prediction model shows that FRPM pipe culvert has good fatigue performance, and the fatigue life can meet the service requirements.

Key words: FRPM pipe culvert, deformation rate, fatigue performance, residual stiffness theory