疲劳荷载作用下栓钉连接件的抗剪承载力退化规律

Shear capacity degradation law of stud connectors under fatigue loading

为了解钢-混凝土组合结构中栓钉连接件在疲劳荷载后的力学特性,针对栓钉推出试件进行静载破坏试验、完全疲劳试验以及非完全疲劳破坏试验.在此基础上归纳了已有栓钉连接件的非完全疲劳破坏的相关试验数据,将疲劳循环次数和剩余抗剪承载力这两个参数作归一化处理,使得所有试验数据具备可比性;同时基于剩余强度理论,推导出适用于栓钉连接件的剩余承载力计算模型,并通过试验数据拟合确定其参数;最后通过若干文献的试验数据进行验证分析.结果表明:在疲劳荷载作用下,栓钉连接件的剩余承载能力呈现先慢后快的非线性退化趋势.所提出的栓钉连接件承载力幂指数退化模型可以较好地描述栓钉连接件的剩余承载力随疲劳循环次数的变化规律.

To explore the mechanical properties of the stud connectors under fatigue loading in steel-concrete composite structures, static, fatigue and non-complete fatigue loading tests for stud connectors were conducted. Based on this, the existing non-complete fatigue push tests for stud connectors were summarized. Two parameters including fatigue life cycle and residual shear capacity were normalized, making all the tests comparable; in addition, based on residual strength theory, an applicable residual bearing capacity model of the stud connectors was developed and the parameters were fitted by the test data. Finally, the established model was verified through the data in literature. The resuks show that the residual bearing capacity of stud connectors presents a nonlinear trend of ＇ slow first and fast later＇ after fatigue loads. The proposed exponential degradation model can well describe variation law of residual shear capacity of the stud connectors under a certain number of fatigue loads.