热轧方矩管连续梁塑性承载力研究

REASEARCH ON THE PLASTIC BEARING CAPACITY OF HOT-ROLLED SHS/RHS CONTINUOUS BEAMS

为研究热轧方矩管连续梁在荷载作用下的塑性承载力,采用有限元软件ABAQUS建立考虑几何初始缺陷和残余应力的有限元模型。基于已有的试验数据,验证了建立的有限元模型的正确性,分析钢材的强度等级、截面高宽比、板件宽厚比、集中荷载作用位置对连续梁塑性承载力的影响。将有限元结果与连续强度法、欧洲规范EN 1993-1-1的计算结果进行对比。结果表明:对于欧洲规范中的Ⅱ类截面,塑性设计建议允许适用。与现有设计方法对比,连续强度法是一种更为有效的设计方法,能够很好地考虑塑性重分布。最后,基于大量的数值研究,提出了适合连续梁塑性设计的截面相对宽厚比的建议值。

In order to study the plastic bearing capacity of hot-rolled SHS/RHS continuous beams under load, finite element software ABAQUS was used to establish a finite element analysis model, which considering both local geometric initial imperfections and residual stresses. Based on the collected test data, the accuracy of the finite element model established by ABAQUS was verified, then the influence of steel strength grade, height-width ratios of section, width-thickness ratio and location of concentrated load on plastic bearing capacity of continuous beam was analyzed. The finite element analysis results were compared with the results of continuous strength design method and EN 1993-1-1, the results showed that for the Class II cross-section in the EN 1993-1-1, the plastic design proposal is allowed to apply. Compared with the existing design methods, the Continuous Strength Method is a more effective design method, it can well take plastic redistribution into consideration. Finally, based on a large number of numerical studies, the recommended values for the relative width-thickness ratio of the section for the plastic design of continuous beams were proposed.