高强钢端板连接节点弯矩-转角曲线数学模型

Mathematical Model for Moment-Rotation Curve of High Strength Steel Endplate Connections

摘要:

为预测高强钢端板连接节点在常温、火灾下及火灾后的弯矩-转角曲线，以四参数指数模型为基础，基于组件法和等效T型连接，提出了初始刚度、屈服后刚度和抗弯极限承载力的计算方法，将计算结果代入四参数指数模型得到预测高强钢端板连接节点弯矩-转角曲线的方法；与足尺试验中Q690和Q960高强钢端板连接节点在常温、火灾下及火灾后的共10组试验结果进行对比。结果表明，抗弯极限承载力的计算结果与试验值较吻合，其中Q960的相对误差在5%以内，初始刚度的计算结果比欧洲钢结构设计规范（EN 1993—1?8）的结果更接近试验值，预测的Q960高强钢端板连接节点弯矩-转角曲线与试验结果吻合，而Q690预测结果偏于安全。

Abstract:

In order to predict the moment-rotation (M-θ) curve of high strength steel endplate connections at ambient temperature, in fire and after fire, a calculation method for initial stiffness, post-yield stiffness, ultimate flexural resistance and shape parameter is proposed based on the four parameter exponential function, the concept of component method, and equivalent T-stubs. The prediction of moment-rotation curve is then obtained by substituting calculation results into the four parameter exponential function. Moreover, the calculation results and predicted moment-rotation curves are compared with the test results of Q690 and Q960 high strength steel endplate connections at ambient temperature, in fire and after fire. The comparisons demonstrate that the calculation values of flexural resistance are in good agreement with the test values, particularly the relative errors of Q960 are within 5%. Besides, the calculation values of initial stiffness are closer to the test results than those of EN 1993—1?8. Moreover, the predicted moment-rotation curves of Q960 are consistent with the test results and those of Q690 are relatively conservative.