计算模型对简支箱梁和T梁剪力滞结果影响

Influence of Calculation Model on Shear Lag Results of Simple-Supported Box and T Beam

以剪力滞效应为研究对象,分别采用MIDAS和ANSYS两种软件配合不同的荷载形式、单元类型和网格密度对一个简支箱梁模型和一个实际简支T梁结构进行计算对比,分析了模型参数和荷载类型对所得结果的影响,为剪力滞效应的有限元分析提供了参数。研究表明:对于同一计算工况,ANSYS比MIDAS所得应力幅值略大,实体单元比板单元所得应力幅值略大,高密度网格比低密度网格所得应力幅值略大,但偏差大都在±5%以内;当腹板与顶板无承托时,对于任意荷载作用,两种软件的1倍网格板单元即可准确得到顶板的剪力滞效应;当腹板与顶板有承托时,在点荷载和线荷载作用下,可采用板单元进行顶板的剪力滞效应分析,但对面和体荷载,则需要采用实体单元进行分析,并且均可采用1倍网格密度。

Taking shear lag effect as the research object,a simple-supported box girder model and a practical simple-supported T-beam structure were calculated and compared by using MIDAS and ANSYS software respectively,combined with different load forms,element types and grid density.The influence of model parameters and load types on the obtained results was analyzed,which provided parameters for the finite element analysis of shear lag effect.The research indicates that:under the same calculation condition,the stress amplitude of ANSYS is slightly larger than that of MIDAS,the stress amplitude of solid element is slightly larger than that of plate element,and the stress amplitude of high density grid is slightly larger than that of low density grid,but the deviation is mostly within ±5%.For the situation that there is no haunch at web and top flange,under arbitrary loads,the shear lag effect of roof can be accurately obtained by 1 time grid plate element of two kinds of software.If there is haunch at web and top flange,the shear lag effect of top flange can be analyzed by plate element under point load and line load.However,for both surface and body load,the solid element analysis is needed,and 1 time grid density is applicable for the both conditions.