H形钢构件双向压弯下全过程弯矩计算模型

THE BENDING MOMENT CALCULATION MODEL OF H-SECTIONAL STEEL MEMBERS SUBJECTED TO BIAXIAL BENDING AND AXIAL FORCE IN THE WHOLE LOADING PROCESS

为探究可发展全截面塑性的H形钢构件在双向压弯加载全过程中塑性应力及两主轴弯矩的发展机制,基于经由已有实验数据校核过的建模方法,采用ABAQUS建立了不同轴压比、腹板和翼缘宽厚比的H形截面构件在不同加载角度下的参数分析模型。结合有限元分析结果,考察了双向压弯下H形截面钢构件的塑性应力发展规律,引入平截面假定,对其应力分布形式进行一定的简化处理。进一步,通过最小二乘法拟合得到相关参数,建立加载位移、塑性发展程度和宏观承载能力三者之间内在联系,构建H形钢构件双向弯矩的理论计算模型。该模型充分考虑了截面尺寸、位移加载方向角、轴压比和加载位移的影响。通过对模型计算结果的分析,验证了该模型可得到构件在加载任意时刻的应力分布形式,并为考虑一定截面塑性发展的双向抗弯设计提供更为简便的设计方法。

To explore the development mechanism of plastic stress and biaxial bending moment of plastic H-section steel members subjected to biaxial bending and axial force,parametric analysis models of H-section members with different axial force ratios,web and flange width-thickness ratios and different loading angles were developed in ABAQUS based on the modeling method verified against existing experimental data.Combined with the finite element analysis results,the plastic stress development law of H-section steel members under biaxial bending was investigated.The plane section assumption was introduced to simplify the stress distribution.Furthermore,the relevant parameters were obtained by the least square fitting,and the internal relations among loading displacement,plastic development degree and macroscopic bearing capacity were established.The theoretical calculation model of bidirectional bending moment of H-shaped steel members was established.The model fully considers the influence of sectional dimensions,displacement loading direction angles,axial compression ratios and loading displacement.Through the analysis of the model calculation results,it was verified that the model can obtain the stress distribution form of the component at any time of loading,and provide a simpler design method for the bidirectional bending design considering a certain degree of plastic development.