框架桥在不同列车速度下的瞬态动力响应

以普通混凝土框架桥工程为研究对象，采用有限元分析软件中的实体单元solid65建立了混凝土框架桥数值模型.利用完全法瞬态动力计算分析得到的框架桥跨中节点的挠度-时间曲线，可以反映出列车在不同速度下通过框架桥时桥体发生的动态响应特征，即框架桥的位移响应特征.结果表明，90~120 km/h为列车通过框架桥的最佳速度区间，此时框架桥的动态挠度时程曲线呈缓慢地上下波动，该速度区间下桥体的最大变形量为2.79×10^-5 m，位置发生在跨中附近，时间发生在列车经过跨中位置的前后时刻.

Transient Dynamic Response of Frame Bridge to Train at Different Speeds

With an ordinary concrete frame bridge project as the research object, a numerical model of concrete frame bridge was established with the solid element Solid65 in the finite element analysis software. The deflection-time curve of the mid-span joints of the frame bridge was obtained through transient dynamic calculation and analysis of the complete method, which reflected the dynamic response characteristics, the displacement characteristics of the frame bridge when the train passed through the frame bridge at different speeds. The analysis results showed that 120~150 km/h was the optimal speed interval for the train to pass through the frame bridge. At this speed interval, the dynamic deflection time-history curve of the frame bridge tended to be flat, and the maximum deformation of the bridge body was 1.88×10-2mm which occurred near the mid-span before and after the train passed through the mid-span.