中文摘要：

为分析单箱三室箱梁的动力特性,采用统一分析梁模型,利用有限节线法计算单箱三室箱梁自由振动时的前三阶频率和振型,揭示此类箱梁在自由振动时所表现出来的动力特性,并绘制出其上翼缘板的振型图。算例的计算结果表明,单箱三室箱梁在其非对称轴方向的振动与其横截面绕轴线的扭转振动是耦合在一起的。

英文摘要：

A unified analytical beam model and a finite nodal-line method are employed to analyze the dynamic properties of a single-box three-cell girder,for the purpose of computing the first three order vibration frequencies and vibration modes and the investigation into the vibration characteristics of the girder,with the help of the diagrams of top flange vibration modes.Computational results show that the vibration in the non-symmetricaxis direction of the girder are coupled together with the torsional vibration of the cross section.