考虑剪切效应的工字梁弯曲应力比拟杆法

BAR SIMULATION METHOD FOR BENDING NORMAL STRESS OF I-BEAM IN CONSIDERATION OF SHEAR EFFECT

随着工字形短深梁和宽翼缘梁结构的发展,截面非线性剪切变形对弯曲应力的影响愈加突出,导致传统设计中所采用的初等梁理论计算结果误差较大,不再适用。本文基于比拟杆法综合考虑剪切效应,推导出工字形梁横力弯曲应力解析计算公式,并与有限元及现有解析计算方法进行对比分析。结果表明:当跨高比较小,翼缘腹板面积比较大时剪切效应对弯曲变形有显著影响。同时相比于现有解析方法,本文计算结果精度较高且适用范围更广,可用于梁结构设计。

With the wide use of I-section short,deep beams and wide flange beams,the section nonlinear effect of shear deformation on the bending normal stress becomes an important issue,because enormous calculation errors will occur by using the traditional beam theory in the design.With the bar simulation method,formulas are derived in this paper for the calculation of the bending normal stress with consideration of the shear effect and results are compared with those obtained by various analytical methods and theˉnite element numerical simulation results.The results indicate that whenffis small oráis large,the bending de flection is affected greatly by the transverse shear.Besides,compared with the existing analytical methods,the proposed method offers more accurate results with an extended scope of application,which can be used for the structural design.