斜拉拱桥自振特性分析

以湘潭市湘江四桥为例,利用大型通用有限元程序建立了斜拉拱桥的2种三维空间有限元模型,计算该桥梁结构的自振频率和振型,分析主要结构参数对振动特性的影响,并与同等跨度的系杆拱桥自振特性进行对比分析。从计算数据可以看出,梁杆系模型具有足够的精度,是一种较为合理适用的分析方法。横向刚度对结构的稳定性起控制作用,该桥横撑位置和数目的变化对结构的自振特性影响较大,其数目适当增加,能有效提高结构的横向刚度,而斜拉索和索塔刚度对其影响相对较小。上述结果和结论可为该桥的设计、施工以及使用阶段的健康检测和维护提供技术参数和依据。

Self-vibration characteristics analysis of cable-stayed arch bridge

The fourth Bridge of Xiangjiang River in Xiangtan City was a good example,in which the two kind of three-dimensional finite element models were established.The natural frequency and modes were calculated.Additionally the influence of primary structural parameters to the self-vibration characteristics was analyzed through the application of the finite element analysis method.The self-vibration characteristics of the bridge was comparied with a coequal span tied arch bridge.The results show that beam model has sufficient accuracy,so it is a reasonable method.Lateral stiffness has a main control on the structural stability.The change of braces' position and number of the bridge has an obvious effect on self-vibration characteristics.The increasing number of braces can increase the structral lateral stiffness effictively.On the other hand,the stiffness of cable and tower has a less effect on it.The calculating results and conclusions can offer the related technical parameters and basic data for the design certification,construction,health detection and maintenance.