690MPa高强钢薄壁方形截面轴压构件承载力直接强度法研究  

Study on direct strength method for the ultimate carrying capacity of 690MPa high-strength steel thin-walled square box section centric compression member

作　　者：申红侠[1,2] 王超 SHEN Hongxia;WANG Chao(School of Civil Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;Key Lab of Structural Engineering and Earthquake Resistance,Ministry of Education(Xi’an University of Architecture and Technology),Xi’an 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,西安710055 [2]结构工程与抗震教育部重点实验室(西安建筑科技大学),西安710055

出　　处：《建筑结构》2021年第18期47-52,8,共7页Building Structure

基　　金：国家自然科学基金项目(51978563)。

摘　　要：与有效宽度法和有效屈服强度法相比,直接强度法更简单。采用ANSYS有限元软件建立模型分析了名义屈服强度f_(y)为690MPa高强钢薄壁方形截面轴压构件的极限承载力,并和直接强度法、修正的直接强度法相比较。主要参数:板件宽厚比b/t=23,30,40,50和60;构件长细比λ=20,30,40,50,60,70,80和90。研究结果表明:对f_(y)=690MPa的薄壁方形截面(b/t>20)轴压构件,采用直接强度法和修正直接强度法计算时,其稳定系数采用《钢结构设计标准》(GB 50017—2017)中的a类曲线;对长细比70≤λ≤90的构件,3种方法均偏保守;对长细比20≤λ<70的构件,在大部分宽厚比范围内,Kwon等提出的修正直接强度法能较好地预测有限元计算结果,直接强度法偏于不安全,Shen Hongxia提出的修正直接强度法偏安全。Direct strength method(DSM)is simpler compared to effective wide method and effective yield strength method.The ultimate carrying capacities of thin-walled square box section centric compression members made from high-strength steel with a nominal yield stress of 690 MPa were analyzed by ANSYS finite element program and compared with the DSM and modified DSM.The plate width-to-thickness ratio(b/t)was taken as 23,30,40,50 and 60 and the member slenderness ratio(λ)as 20,30,40,50,60,70,80 and 90.The study shows that curve a provided in Standard for design of steel structures(GB 50017—2017)should be employed for thin-walled square box section(b/t>20)centric compression members with f_(y)=690 MPa when using the DSM and modified DSM,that the DSM and modified DSM proposed by Kwon etc.and Shen Hongxia are conservative for members with 70≤λ≤90,that the modified DSM proposed by Kwon etc.can accurately predict the finite element results and the DSM is unsafe and the modified DSM proposed by Shen Hongxia is safe over a wide range of wide-to-thickness ratios for columns with 20≤λ<70.

关 键 词：高强钢 薄壁方形截面 轴压构件 局部-整体相关屈曲 极限承载力 直接强度法 修正的直接强度法 

分 类 号：TU391[建筑科学—结构工程] TU323.1