斜交连续箱梁桥剪滞效应分析

Analysis of Shear Lag Effect of Skew Continuous Box Girder Bridges

运用ANSYS程序中的shell63单元,分析了集中荷载、均布荷载作用下斜度为30°和45°的斜交箱梁剪滞效应的纵、横向分布规律,并与相应正交箱梁进行了比较,结果表明,跨中断面的剪滞系数随着斜度的增大变化不明显.但对中支承断面,靠斜支承点一侧的剪滞系数随斜度增大而增大,而远离斜支承点一侧的剪滞系数则随斜度的增大而减小.分析斜交连续箱梁剪滞效应的纵向分布规律时,出现了明显的负剪力滞效应,而且比相应正交箱梁严重.总之,斜交箱梁的剪滞效应比正交箱梁更为明显,设计时必须充分考虑其剪滞效应.

Based on shell63 element of ANSYS, skew box girders with thirty degrees and forty-five degrees of skew are analyzed respectively to investigate longitudinal and transversal distributions of shear lag effect under Concentrated or uniform force,and they are compared with the corresponding right box girders. The result shows that with the＇enlargement of degrees of skew, shear lag factors of two webs of midspan cross -section A-A have not more remarkable Change. However, to cross-section P-B, with the enlargement of degrees of skew,shear lag factors near abutment enlarge and shear lag factors far away from abutment decrease. When skew continous box girders are analyzed respectively to investigate longitudinal distributions of shear lag effect,there is a kind of phenomenon of negative shear lag effect,and the phenomenon is more serious than that of a right box girder. In a word, a skew box girder has more remarkable shear lag behavior than a right box girder. Shear lag effect must be fully considered in the design of a skew box girder.