Q460高强钢焊接工字形截面双跨连续梁整体稳定性能与设计方法研究

Overall Stability Behavior and Design Method of Q460 High Strength Steel Welded I-section Two-span Continuous Beam

为了研究Q460高强钢焊接工字形截面双跨连续梁的整体稳定性能以及完善规范中关于此类构件的设计方法,采用ANSYS有限元程序建立考虑残余应力的有限元模型,根据已有普通强度Q345钢双跨连续梁的试验数据验证有限元模型的正确性。利用经试验验证的有限元模型,分析残余应力分布模式、跨度比、钢材强度、截面高宽比以及加载比例等因素对连续梁整体稳定性能的影响。基于有限元分析结果,回归出双跨连续梁弹性临界弯矩计算公式,将该公式计算结果代入《高强钢结构设计标准》(JGJ/T 483-2020)中受弯构件整体稳定系数计算公式求得整体稳定系数,并与有限元分析计算得到的整体稳定系数进行对比,比较结果表明二者相差不大且规范计算结果偏于安全,回归得到的双跨连续梁弹性临界弯矩计算公式带入规范公式计算整体稳定系数的方法适用于Q460高强钢双跨连续梁的整体稳定设计。

In order to investigate the overall stability behavior of Q460 high strength steel welded I-section two-span continuous beam and develop the design method of such beams in codes,a finite element model considering residual stress was established by using ANSYS finite element program,and the model was verified on the basis of experimental data of Q345 steel two-span continuous beam.With the finite element model verified by experiment,the overall stability behaviors were investigated by changing the residual stress distribution model,span ratio,steel strength,section height-width ratio,and loading ratio.According to the finite element analysis results,the formula of elastic critical moment was regressed.Furthermore,the elastic critical moments obtained through the above formula were substituted into the overall stability factor formula in the specification for design of high strength steel structures(JGJ/T 483-2020)to obtain overall stability factor,which was compared with that obtained by finite element analysis.The comparison results indicate that the above method is suitable for the overall stability design of Q460 high strength steel two-span continuous beam.