扁平曲线箱梁静动力特性分析

应用空间有限元方法，建立了考虑不同力学因素的扁平曲线箱梁分析模型；通过对不同曲率半径的扁平曲线箱梁桥的静动力特性进行计算分析，明确了结构主要部位的活载支承反力、变位和内力随曲率半径的变化规律；得出了弯曲、翘曲、畸变和剪力滞等应力成分的变化规律和分布特点；分析了曲率半径、翘曲、畸变、剪力滞后和剪心形心不重合等效应对结构自振特性的影响。对移动荷载车列作用下结构空间弯扭耦合振动特性进行研究，得出了位移动力系数及截面应力冲击系数的分布特点。结果表明，位移动力系数随速度增大是幅值和周期都在增大的似半正弦波曲线．并且其随半径增大而逐渐减小。

Analysis for Static and Dynamic Characteristics of Flat Curved Box Beam

The special finite element models of flat curved box beams are established. Based on the static and dynamic calculation and analysis of models with different curvature radius, support reaction, displacement, inner force, component and distribution of the stresses of bending, warping, distortion and shear-lag of main parts of the box beams under live loads and their variational laws with curvature radius are revealed.The effect of different parameters, which include curvature radius, warping, distortion, shear-lag and noncoincidence of shear centre with figure centre, on the natural vibration characteristics of structures are analyzed.The space flexuraltorsional coupled vibration of the flat curved box beams under the action of moving vehicle series is studied, and the displacement dynamic load factor and the section stress dynamic load factor are obtained.The analysis results show that the variational law of displacement dynamic load factor is as half-sine wave whose amplitude and periodicity increase with the growth of the speed of moving vehicle, and the displacement dynamic load factor decrease with the growth of the curvature radius.