移动荷载速度对悬臂曲线箱梁剪力滞效应的影响

利用三维有限元通用软件ANSYS,设置相同的悬臂长度、弹性模量、泊松比和密度等参数,分别考察了7种不同的移动荷载速度对悬臂曲线箱梁和悬臂直线箱梁中剪力滞效应的影响.重点分析了荷载以不同速度移动到悬臂箱梁L/2处时该横截面上应力分布及剪力滞系数变化规律.结果表明:在移动荷载作用下,两种悬臂箱梁L/2处横截面上均出现正剪力滞现象;剪力滞系数随着移动荷载速度的增大而增大,当移动荷载速度小于2m/s时,剪力滞系数增长缓慢;当移动荷载速度超过2m/s时,剪力滞系数增长较快;悬臂曲线箱梁内侧剪力滞系数明显大于外侧剪力滞系数,悬臂直线箱梁剪力滞系数分布曲线介于悬臂曲线箱梁内侧与外侧剪力滞系数分布曲线之间.

Moving load speed on shear lag effect of cantilever curved box girder

Using general software of a three dimensioned finite element ANSYS,the shear lag effect un- der seven different moving load speed was respectively investigated in the cantilever curved and straight box girder while setting up the same parameters such as length, elastic modulus, Poisson＇s ratio and density. The distribution of section stress and shear lag coefficient was mainly analyzed when the loads moved to the mid-span of the cantilever box girder. The results show that under the effect of moving load, the positive shear lag phenomena are confirmed in mid-span sections of the two box girders; the shear lag coefficient increases with the increase of moving load speed, it increases slowly when moving load speed is less than 2 m/s,but it increases quickly when moving load speed exceeds 2 m/s;the inside shear lag coefficient of curved box girder is obviously bigger than that of the outside;the shear lag coef- ficient distribution curve of cantilever straight box girder was between the curves of inside and outside coefficient distribution of the curved box girder.