基于有限元的高铁40 m箱梁抗弯性能分析  

Analysis on Bending Performance of 40 m Box Girder for High Speed Railway Based on Finite Element Method

作　　者：刘高波 吕茂桦 蒋欣 LIU Gaobo;LYU Maohua;JIANG Xin(Hunan Shangshang Municipal Construction and Development Co.,Ltd.,Changsha Hunan 410004,China;School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan Hubei 430074,China)

机构地区：[1]湖南尚上市政建设开发有限公司,湖南长沙410004 [2]武汉工程大学土木工程与建筑学院,湖北武汉430074

出　　处：《中国铁路》2024年第10期27-33,共7页China Railway

基　　金：湖北省自然科学基金计划项目(2022CFB256);研究生教育创新基金项目(CX2023360)。

摘　　要：高速铁路40 m箱梁具有结构性能优异、工程适应性好等特点,尤其应用于跨越沟谷河流较多的西部山区时,能显著减少下部结构的工程造价。为深入了解高铁40 m简支箱梁的抗弯性能,应用混凝土塑性损伤模型开展三维有限元分析,并参照既有的静载弯曲试验结果对模型进行验证。高铁40 m箱梁在开裂前其挠度-荷载曲线呈线性,中性轴距梁底约2 130 mm;开裂后挠度-荷载关系为略凸的曲线,中性轴随加载值的增加而不断上升,待2.00级加载等级后中性轴上升至腹板与顶板交接处;箱梁开裂后可基于损伤因子来评估跨中箱梁底板与腹板内不断发展的竖向弯曲裂缝与斜向弯剪裂缝,以及距梁端1/4梁长范围内的斜向腹剪裂缝。基于有限元分析可知高铁40 m简支箱梁具有良好的裂后塑性性能。The 40 m box girder for High Speed Railway features excellent structural performance and good engineering adaptability,which can significantly reduce construction cost of substructure especially when applied in the western mountainous areas with many valleys and rivers.In order to gain a deeper understanding of the bending performance of the 40 m simply-supported box girder for High Speed Railway,this paper conducts a three-dimensional finite element analysis using a concrete plastic damage model,and verifies the model with reference to existing static load bending test results.Before cracking,the deflection-load curve of the 40 m box girder for High Speed Railway exhibits a linear relationship,and the distance between neutral axis and girder bottom is about 2,130 mm.After cracking,the deflection-load relationship becomes a slightly convex curve,and the neutral axis rises continuously with the increase of loading value.After reaching a loading level of 2.00,the neutral axis rises to the joint between web plate and top plate.After the cracking of the box girder,the vertical bending cracks and diagonal bending shear cracks developing in the bottom plate and web plate of the mid-span box girder,as well as the diagonal web shear cracks within 1/4 girder length from the girder end,can be evaluated based on the damage factor.Based on the finite element analysis,it can be seen that the 40 m simply-supported box girder for HSR has good post-cracking plastic performance.

关 键 词：高速铁路 40 m箱梁 抗弯性能 有限元 塑性损伤模型 

分 类 号：U238[交通运输工程—道路与铁道工程] U442[建筑科学—桥梁与隧道工程]