DOI: 10.15986j.1006-7930.2018.04.001
针对桥梁波纹腹板钢箱梁,进行了四点受弯静载试验,采集了不同等级荷载下沿翼缘和腹板检测线方向的磁信号,分析了弹性和塑性阶段沿检测线方向磁信号及其梯度值的变化规律,找出了表征应力集中程度及区域的特征磁信号,得出如下结论:第一,在波纹腹板钢箱梁的四点受弯试验中,过零点的位置不能表征应力集中位置及破坏位置,磁信号过零点的经验判断并不适用; 第二,弹性和塑性阶段磁信号变化曲线相似,弹性阶段的特征磁信号能够较好地表征应力集中程度,塑性阶段特征磁信号不能很好地表征应力集中程度; 第三,利用钢箱梁跨中挠度和磁信号梯度值绝对值曲线中的转折点可以找出钢箱梁屈服时挠度.
The flexural loading test of tilt corrugated web steel box girder are conducted by four-point bending pattern. In the same time, the magnetic signal along the lines of flange and web direction of this beam under different load level of the whole loading process are collected. The change rule of the magnetic signal and its gradient values during the elastic and plastic stage are analyzed, and the characteristics of the magnetic signals to describe the stress concentration degree and the position of beam are extracted by experimental data. Conclusion are obtained as following: First, in the four-point bending test of corrugated web steel box girder, a zero value of magnetic signal can't indicate the stress concentration position of beam, the judgment methods of magnetic signals passing zero value may have some mistake. Second, magnetic signal curves of the elastic and plastic stage of tilt corrugated web steel box girder are similar. The magnetic signal characteristics of the elastic stage can indicate the stress concentration degree very well, while the magnetic signal characteristics of plastic phase can't indicate the stress concentration degree. Third, the deflection degree value in the mid span on the yield stage of the steel box girder can be calculated by using the mutation point of magnetic signal curve and absolute value of gradient curve.
