集中荷载下钢筋混凝土简支T型梁剪力滞效应

Shear Lag Effect of Simply Supported Reinforced Concrete T-Beam Under Concentrated Load

通过对钢筋混凝土简支T型梁进行两点加载试验,研究T型梁翼板内不同截面的剪力滞效应,并通过Abaqus有限元软件对T型梁的加载全过程进行模拟.试验结果表明:简支T型梁在靠近支座位置存在负剪力滞区,随着荷载增大,负剪力滞效应逐渐增强,并且负剪力滞区出现受拉现象,拉应力达到2.34 MPa,而在纯弯段,荷载的增大对剪力滞系数影响不大;T型梁翼板内的剪力主要发生在翼板和腹板交界处,剪力在向翼板边缘传递的过程中快速衰减,在翼板没有出现裂缝前,剪力滞效应随着腹板厚度的增加而降低,但是降低的程度随着腹板厚度的持续增加而减小.

Through the two-points loading experiment of the simply supported reinforced concrete T-beam,the shear lag effect of different sections in the flange of T-beam was studied,and the whole loading process of T-beam was simulated by Abaqus finite element software.The experiment results show that there is negative shear lag zone near the support of T-beam,and the negative shear lag effect increases gradually with the increase of load,and the tensile phenomenon appears in negative shear lag zone,the tensile stress reaches 2.34 MPa.In the pure bending section,the increase of load has little effect on the shear lag coefficient.The shear stress in the flange of T-beam mainly occurs at the joints of flange and web,and the shear stress reduces rapidly along the flange.Before cracking in flange,the shear lag effect decreases with the increase of the web thickness,but the degree of decrease reduces with the continuous increase of the web thickness.