集中荷载和均布荷载下T形简支梁不同截面的剪力滞效应

Shear Lag Effect of Simply Supported T-Beam on Different Sections Under Concentrated Load and Uniform Load

对有机玻璃T形简支梁进行两点集中加载和均布加载,研究T形简支梁不同截面的剪力滞效应,分析正、负剪力滞的产生原因和传递机理.试验结果表明:T形简支梁支座位置存在明显的负剪力滞效应,且随着荷载的增加,负剪力滞效应增强,远离支座截面则为明显的正剪力滞现象,有效翼缘宽度为正;集中荷载作用时,剪力滞效应随着荷载的增加而逐渐减弱,均布荷载作用时,剪力滞效应随着荷载的增加先逐渐增强,后逐渐减弱;剪力滞效应主要集中在腹板对应的翼板处,向两侧逐渐减弱,且不可简单地根据剪力滞系数推断剪力滞效应的正负.

Two-point concentrated load and uniform load were applied on the plexiglass simply supported T-beam,the shear lag effect of different sections of the simply supported T-beam was studied.The causes and transfer mechanism of the positive and negative shear lag were analyzed.The test results show that:obvious negative shear lag effect exists at the support position of simply supported T-beam,and as the load increases,the negative shear lag effect increases;obvious positive shear lag exists at the section away from the support,the effective flange width is positive.Under the concentrated load,the shear lag effect gradually weakens as the load increases.Under the uniform load,the shear lag effect gradually increases firstly and then decreases gradually as the load increases.The shear lag effect mainly concentrates in the corresponding flange of the web and gradually decreases to the sides.The positive or negative of the shear lag effect cannot be judged simply by the shear lag coefficient.