Q420等边角钢轴压杆稳定性能研究(Ⅰ)——残余应力的试验研究  

Stability of Q420 high strength steel equal-leg angle members under axial compression (Ⅰ):Experimental study on the residual stress

作　　者：班慧勇[1] 施刚[1] 邢海军[2] 李茂华[2] 石永久[1] 王元清[1] 

机构地区：[1]清华大学,北京100084 [2]中国电力科学研究院,北京100055

出　　处：《土木工程学报》2010年第7期14-21,共8页China Civil Engineering Journal

基　　金：国家自然科学基金项目(50708051);"十一五"国家科技支撑计划重点项目(2006BAJ03A02-1)

摘　　要：高强度钢材逐步开始在钢结构实际工程中得到应用,其中包括大型输电铁塔中Q420高强角钢的应用。但目前针对此类钢材轴压杆的稳定性能研究还很少,其中一个很重要的原因在于对构件初始缺陷(主要是残余应力)的研究非常匮乏。本文采用分割法对Q420高强等边角钢的纵向残余应力进行了试验量测,试验对象包括5种截面尺寸共计15个试件。基于试验结果,本文分析了Q420高强等边角钢残余应力的分布特点和数值大小,并与国内外普通强度角钢的残余应力试验结果和规范采用的残余应力分布模型进行了对比,结果表明,残余应力分布形式和绝对数值大小与钢材强度没有直接关系,但截面板件的宽厚比则会影响残余应力的大小。最后,本文提出了适用于Q420高强等边角钢的较为准确和安全的残余应力分布模型和计算公式。这为进一步研究该类钢材截面的轴压构件稳定性能提供了前提条件。High strength steels have been applied in many steel structures, including the application of Q420 high strength steel angles of nominal yield strength of 420MPa in large transmission towers. But research on the stability behavior of such steel members under axial compression is lack, due to the lack of study of effect of initial imperfections on the residual stress. An experimental study of the residual stress of Q420 high strength steel equal-leg angles is conducted, including 5 types of sections and 15 specimens. Based on the test results, the residual stress distribution and magnitude of Q420 equal-leg angles are analyzed, and compared with the test results for ordinary strength steel angles and the distribution models in the design code. It shows that the residual stress distribution and magnitude are not related to steel yield strength, while the slenderness of the section plate has some effects. Residual stress distribution models and calculation formulas for Q420 high strength steel equal-leg angles are proposed, serving as a base for further study of the buckling behavior of such steel members under axial compression.

关 键 词：钢结构 高强度角钢 残余应力 分割法 试验研究 分布模型 

分 类 号：TU391[建筑科学—结构工程]