预应力FRP筋混凝土梁的抗震性能试验研究

进行了8根混凝土梁在低周反复荷载下的拟静力试验,对其受力过程、破坏特征、滞回特性、骨架曲线、延性、刚度退化、耗能能力等抗震性能进行分析比较,研究不同预应力筋种类和预应力度(PPR)对预应力梁抗震性能的影响。考虑材料的非线性,对试验梁进行有限元计算分析。有限元计算和试验结果表明,预应力度是影响预应力梁抗震性能的主要因素,抗震性能随着预应力度的增加而逐渐降低;在同等预应力度的条件下,无粘结预应力FRP筋混凝土梁的耗能能力最好;采用有粘结和无粘结预应力相结合后,试验梁的延性指标有所提高,延性比有粘结和无粘结预应力梁分别提高12%和26%,滞回曲线变得更加丰满,对结构抗震性能有利;有限元计算结果与试验结果较为吻合。

Experimental studies on the seismic performance of concrete beams prestressed with FRP tendons

Based on low reversed cyclic loading experiments of 8 concrete beams,failure pattern,hysteresis curve,ductility,rigidity degeneration,energy dissipation were systematically studied.The effects of prestressing tendon type and prestressing ratio(PPR) on seismic performance were investigated.Studies show that the prestressing ratio is the main factor to affect the seismic performance of prestressed beams,which gradually decreased with the increase of prestessing ratio.If the prestressing ratio remained the same,the energy dissipation capacity of unbonded prestressed concrete beams was better than bonded prestressed beams.With combined bonded and unbonded prestressed FRP tendons,the ductility ratio of the beams was increased by 12% and 26%,respectively,as compared with the ductility ratio of bonded and unbonded prestressed beams,and the hysteretic curve became more plump.Finite element analysis was conducted using nonlinear material model,and the results were close to the test data.