Fatigue and post fatigue monotonic behaviour of partially prestressed concrete beams
Fatigue and post fatigue monotonic behaviour of partially prestressed concrete beams
复制标题
部分预应力混凝土梁的疲劳和疲劳后单调行为
DOI：
10.1680/macr.14.00388
复制
发表时间：
2016-02-01
影响因子：
2.7
通讯作者：
Yu, Zhiwu
中科院分区：
文献类型：
--
作者：
Song, Li;Hou, Jian;Yu, Zhiwu
本工作的目的是研究疲劳和疲劳后的单调行为的部分预应力混凝土（PPC）梁与高预应力度。对11根大型PPC梁进行了疲劳和单调加载试验。研究分析了荷载水平和疲劳损伤程度对梁疲劳及疲劳后单调性能的影响。结果表明，高预应力梁的疲劳性能取决于所施加的荷载水平。为保证设计的安全性和优化性，建议荷载水平应小于开裂荷载的1“28倍，最大裂缝宽度应控制在0“20 mm，反复荷载前非预应力钢筋的初始最大应力范围应小于170 MPa。梁的疲劳后单调行为与单调试验前疲劳损伤的严重程度有关。低疲劳损伤仅对梁的单调性能产生轻微影响，而中疲劳损伤和高疲劳损伤分别使梁的极限强度降低高达15 - 2%和18 - 0%，并使变形延性指数增加高达18 - 6%和41.0%。
The objective of this work was to study the fatigue and post-fatigue monotonic behaviour of partially prestressed concrete (PPC) beams with a high degree of prestress. Eleven large PPC beams were tested under fatigue and monotonic loading. The effects of applied load level and severity of fatigue damage on the beams' fatigue and post-fatigue monotonic behaviour were studied and analysed. The results indicated that the fatigue behaviour of beams with a high degree of prestress was dependent on the applied load level. For an optimum and safe design, the applied load level should be less than 1"28 times the cracking load, the maximum crack width should be limited to 0"20 mm and the initial maximum stress range of non-prestressed reinforcing bars before repeated loading should be less than 170 MPa. The post-fatigue monotonic behaviour of beams was related to the severity of fatigue damage prior to the monotonic test. Low fatigue damage was found to have only a slight impact on the monotonic behaviour of the beams, whereas medium and high fatigue damage respectively reduced the ultimate strength by up to 15"2% and 18"0% and increased the deformability ductility index by up to 18"6% and 41.0%.