为研究以栓钉剪切破坏为表征的钢 -混凝土组合梁的疲劳破坏机理及疲劳损伤过程,制作3根钢-混凝土组合梁试件进行疲劳试验,研究组合梁在疲劳荷载作用下的破坏过程、挠度以及混凝土和栓钉应变的变化规律.结果表明:钢-混凝土组合梁的疲劳寿命对疲劳荷载相当敏感,疲劳荷载幅及荷载峰值都会显著影响组合梁的疲劳寿命;以栓钉剪切破坏为表征的钢-混凝土组合梁的疲劳损伤可以分为3个阶段,第1阶段,部分剪力较大的栓钉发生疲劳损伤,但栓钉群的整体抗剪性能无显著变化,组合梁的挠度无显著变化,第2阶段,随着疲劳荷载持续作用,部分栓钉发生严重疲劳损伤甚至断裂,栓钉群的抗剪性能劣化,组合梁的挠度明显增加,第3阶段,大部分栓钉被剪断,钢梁与混凝土板退出协同工作模式.%To investigate the fatigue failure mechanism and fatigue damage processes of the steel and concrete composite beams characterized by the stud shear failure,3 specimens of the beams were prepared and the fatigue tests for the beams were made.The failure processes and de-flection of the beams and the strain change law s of the concrete and studs under the fatigue loads were studied.The results of the study show that the fatigue lives of the beams are very sensitive to the fatigue loads and the ranges and peak values of the fatigue loads have significant influences on the fatigue lives of the beams.The fatigue damage of the beams characterized by the stud shear failure can be divided in to 3 stages,i.e.,at the stage 1,the fatigue damage of part of the studs subjected to the great shear occurs,but the global shear behavior of the group studs and the deflec-tion of the beams does not change significantly.At the stage 2,with the sustaining action of the fatigue loads,the severe fatigue damage or even the breaking of part of the studs occurs,the shear behavior of the group studs starts to deteriorate and the deflection of the beams significantly in-creases and at the stage 3,most of the studs are broken under the shear and the steel beams and concrete deck slabs quit the mode of collaborative work.
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