三跨连续曲线宽箱梁力学特性有限元分析与模型试验

基于梁格法、有限单元法以及比拟正交异性板法的基本原理，针对曲线宽箱梁特殊的截面特点，建立了一种简单实用又具有足够精度的改进梁格法，即比拟板-梁格法，并提出该方法用于梁格划分以及截面特性计算的一般方法；同时，模拟实际工程，建立曲线宽箱梁桥的传统梁格模型、比拟板-梁格模型以及精细的三维实体有限元模型，研究曲线宽箱梁在不同荷载作用下的空间受力情况及内力横向传递机制；制作三跨连续曲线宽箱梁桥的有机玻璃模型，采用静力加载的方式来测得曲梁控制截面上的应变和挠度，并提出用不均匀系数来表达曲线桥的不均匀受力；将试验结果与有限元模型的计算结果进行比较分析，验算比拟板-梁格模型的计算精度及实用性，同时得到了连续曲线宽箱梁的应力与挠度横向分布规律。结果表明:比拟板-梁格模型的计算精度高于传统梁格模型，同实体单元法相比，比拟板-梁格法的模型简单且计算方便，便于工程设计应用。

Finite Element Analysis of Mechanical Properties and Model Test on Three-span Continuous Wide Curved Box Girder

Based on the basic principles of grillage method, finite element method and orthotropic plate simulation method, according to the characteristics of the wide curved box girder cross section, a simple practical modified method with reasonable precision was discussed and put forward, which was called simulated plate-grillage method. Moreover, the generalizing method of grillage meshing and sectional characteristic of this method were presented. Simulated the actual project, the traditional grillage model, simulated plate-grillage model and accurate solid element model of the wide curved box girder bridge were built. Under different loads, the spatial forces and the lateral transfer mechanism of internal forces of wide curved box girder were investigated. A three span continuous wide curved box girder model was made by using plexiglass. With the model static load test, the strain and deflection of the control cross sections of curved girder was measured, the uniformity coefficient was used to express the uneven force of the curved bridge. Compared the finite element analysis results and experimental data, the accuracy and practicality of simulated plate-grillage method were verified. Meanwhile, the distribution law of the stress and deflection of the wide curved continuous box girder was obtained. The results show that the accuracy of simulated plate-grillage model is higher than that of the traditional grillage model. Compared with solid element method, simulated plate-grillage model is more simply and convenient in calculation, and easy to apply in engineering design.