摘要
不同于以往荷载作用于箱梁的肋板处时剪力滞效应的研究,考虑当荷载不作用在箱梁的肋板处时顶板与底板位移及剪力滞效应的差异,对顶板与底板分设不同的纵向位移差函数,采用二次抛物线作为箱梁翼缘板的纵向位移沿梁宽分布函数,通过能量变分法,研究荷载在顶板横向变位下箱梁顶板与底板的位移,应力及剪力滞效应的变化,根据对于简支箱梁受均布荷载作用下跨中剪力滞效应的计算结果,随着作用在顶板的对称荷载从对称中心向肋板处移动,顶板将经历一个产生负剪力滞效应到无剪力滞效应,再到产生正剪力滞效应的过程。而与此同时底板的剪力滞效应规律受荷载的移动的影响很小,始终保持正剪力滞效应。计算结果与有限元数值模拟结果吻合较好,验证了理论的可靠性,同时也说明当荷载不作用在箱梁的肋板处时,对顶板与底板分设不同的纵向位移差函数的考虑是正确的。
The. shear lag effect of the loading not acting on variation of shear lag effect, different functions of longitudinal the top and bottom plates of the box beam and a quadric the webs of box beams was investigated. displacement differences were respectively parabolic was adopted as the function of Due to the assumed for longitudinal displacement along the flange width. By using the energy variational method, the variation of displacement and the stress and shear lag effect on the top and bottom plates of the box beam with varying load locations were investigated. Based ,on the caleulation results, for the simple box beam subjected to uniform load, with the symmetrical loading on the top plate moving from the symmetric enter to the webs, the shear lag effect on the top plate ehanges from negative to posilive, and the shear lag effect on the bottom plate rarely changes and remains positive. The results are in good agreemellt with those from finite element method.
出处
《土木工程学报》
EI
CSCD
北大核心
2007年第10期8-12,共5页
China Civil Engineering Journal
基金
国家自然科学基金(50678076)
关键词
箱型梁
剪力滞效应
荷载位置
能量变分法
box beam
shear lag effect
load location
energy variational method
